Abstract:
The present invention relates to novel herbicidal [l,8]-naphthyridines of Formula (la) or (lb), or an agronomically acceptable salt of said compound wherein R2, R3, R4, R5,R6,R7, R8, n, m, X and Q are as defined herein. The invention further relates to processes and intermediates for the preparation of the [l,8]-naphthyridines, to compositions which comprise the herbicidal compounds, and to their use for controlling weeds, in particular in crops of useful plants.
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Notices, Deadlines & Correspondence
EUROPEAN REGIONAL CENTRE, PRIESTLY ROAD, SURREY RESEARCH PARK, GUILDFORD, SURREY GU2 7YH UNITED KINGDOM
Inventors
1. MITCHELL GLYNN
C/O SYNGENTA LIMITED, JEALOTT'S HILL INTERNATIONAL RESEARCH CENTRE, BRACKNELL, BERKSHIRE RG42 6EY, UNITED KINGDOM
2. SALMON ROGER
C/O SYNGENTA LIMITED, JEALOTT'S HILL INTERNATIONAL RESEARCH CENTRE, BRACKNELL, BERKSHIRE RG42 6EY, UNITED KINGDOM
3. BACON DAVID PHILIP
C/O SYNGENTA LIMITED, JEALOTT'S HILL INTERNATIONAL RESEARCH CENTRE, BRACKNELL, BERKSHIRE RG42 6EY, UNITED KINGDOM
4. ASPINALL IAN HENRY
C/O SYNGENTA LIMITED, JEALOTT'S HILL INTERNATIONAL RESEARCH CENTRE, BRACKNELL, BERKSHIRE RG42 6EY, UNITED KINGDOM
5. BRIGGS EMMA
C/O SYNGENTA LIMITED, JEALOTT'S HILL INTERNATIONAL RESEARCH CENTRE, BRACKNELL, BERKSHIRE RG42 6EY, UNITED KINGDOM
6. AVERY ALARIC JAMES
C/O SYNGENTA LIMITED, JEALOTT'S HILL INTERNATIONAL RESEARCH CENTRE, BRACKNELL, BERKSHIRE RG42 6EY, UNITED KINGDOM
7. MORRIS JAMES ALAN
C/O SYNGENTA LIMITED, JEALOTT'S HILL INTERNATIONAL RESEARCH CENTRE, BRACKNELL, BERKSHIRE RG42 6EY, UNITED KINGDOM
8. RUSSELL CLAIRE JANET
C/O SYNGENTA LIMITED, JEALOTT'S HILL INTERNATIONAL RESEARCH CENTRE, BRACKNELL, BERKSHIRE RG42 6EY, UNITED KINGDOM
Specification
HERBICIDAL COMPOUNDS
The present invention relates to novel herbicidal [l,8]-naphthyridines, to processes for their preparation, to compositions which comprise the herbicidal compounds, and to their use for controlling weeds, in particular in crops of useful plants, or for inhibiting plant growth.
According to the present invention there is provided a herbicidal compound of Formula (la) or Formula (lb) (Formula Removed)
or an agronomically acceptable salt of said compound wherein:-
R2 is selected from the group consisting of C1-C3alkyl, C1-C3haloalkyl, C1-C3alkoxy-C1-C3 alkyl, C1-C3 alkoxy-C2-C3alkoxy- C1-C3-alkyl, C1-C3alkoxy-C1-3-haloalkyl, C1-C3-alkoxy-C1-C3 -alkoxy-C1-C3 -haloalkyl; C4-C6-oxasubstituted cycloalkoxy-C1-C3 -alkyl, C4-C6-oxasubstituted cycloalkyl-C1-C3-alkoxy-C1-C3 -alkyl, C4-C6-oxasubstituted cycloalkoxy-C1-C3 -haloalkyl, C4-C6-oxasubstituted cycloalkyl-C1-C3-alkoxy-C1-C3 -haloalkyl, (C1-C3 alkanesulfonyl-C1-C3 alkylamino)-C1-C3 alkyl and (C1-C3 alkanesulfonyl-C3-C4 cycloalkylamino)-C1-C3 alkyl;
R5 is hydrogen or methyl;
R6 is selected from the group consisting of hydrogen, fluorine, chlorine, hydroxyl and methyl;
R7 is selected from the group consisting of hydrogen, halogen, hydroxyl, sulfhydryl, C1-C6alkyl, C3-C6cycloalkyl, C1-C6haloalkyl, C1-C6haloalkenyl, C2-C6alkenyl, aryl-C2-C6alkenyl, C3-C6alkynyl, C1-C6alkoxy, C4-C7 cycloalkoxy, C1-C6haloalkoxy, C1-Cealkylthio, C1-C6alkylsulfinyl, C1-C6alkylsulfonyl, C1-C6haloalkylthio, amino, C1-C6alkylamino, C2-C6dialkylamino, C2-C6alkenylamino, C1-C6alkoxy-C1-C6-alkylamino, (C1-C6alkoxy-C2-C4-alkyl) -C1-C6-alkylamino,C3-C6cycloalkylamino, C3-C6 cyclohaloalkylamino, C1-C3alkoxy-C3-C6cycloalkylamino, C3-C6 alkynylamino, dialkylamino in which the substituents join to form a 4-6 membered ring (e.g pyrrolidinyl, piperidinyl) optionally containing oxygen (e.g morpholinyl) and/or optionally substituted by C1-C3-alkoxy and/or halogen especially fluorine, C2-Cedialkylaminosulfonyl, C1-C6alkylaminosulfonyl, C1-C6alkoxy-C1-C6alkyl, C1-Cealkoxy-C2-C6alkoxy, C1-C6alkoxy-C2-C6 alkoxy-C1-C6-alkyl, C3-C6alkenyl-C2-Cealkoxy, C3-C6alkynyl-C1-C6alkoxy, C1-C6alkoxycarbonyl, C1-C6alkylcarbonyl, C1-C4alkylenyl-S(O)p-R,, C1-C4alkylenyl-CO2-R', C1-C4alkylenyl-(CO)N-R'R', aryl (e.g. phenyl), phenylthio, phenylsulfinyl, phenylsulfonyl, aryloxy (e.g phenoxy) and 5 or 6-membered heteroaryl or heteroaryloxy, the heteroaryl containing one to three heteroatoms, each independently selected from the group consisting of oxygen, nitrogen and sulphur, wherein the aryl or heteroaryl component may be optionally substituted by a substituent selected from the group consisting of C1-C3alkyl, C1-C3haloalkyl, C1-C3 alkoxy, C1-C3haloalkoxy, halo, cyano and nitro;
X = OorS;
n = 0 or 1;
m = 0 or 1 with the proviso that if m = 1 then n = 0 and if n=l then m = 0;
p = 0, lor 2;
R' is independently selected from the group consisting of hydrogen and C1-C6alkyl.
R8 is selected from the group consisting of hydrogen, C1-C6alkyl, C1-C6haloalkyl, C1-C6alkylcarbonyl-C1-C3alkyl, C3-C6cycloalkylalkeneyl for example cyclohexylmethylenyl, C3-C6alkynylalkylenyl for example propargyl, C2-C6-alkenylalkylenyl for example allyl, C1-C6alkoxy C1-C6alkyl, cyano-C1-C6-alkyl, arylcarbonyl-C1-C3-alkyl (wherein the aryl may be optionally substituted with a substituent selected from the group consisting of halo, C1-C3-alkoxy, C1-C3-alkyl, C1-C3 haloalkyl), aryl-C1-C6alkyl (wherein the aryl may be optionally substituted with a substituent selected from the group consisting of halo, C1-C3-alkoxy, C1-C3-alkyl, C1-C3 haloalkyl), C1-C6alkoxy C1-C6alkoxy C1-C6alkyl, aryl, 5 or 6-membered heteroaryl, 5 or 6-membered heteroaryl-C1-C3-alkyl or heterocyclyl-C1-C3-alkyl, the heteroaryl or heterocyclyl containing one to three heteroatoms each independently selected from the group consisting of oxygen, nitrogen and sulphur, wherein the aryl, heterocyclyl or heteroaryl component may be optionally substituted by a substituent selected from the group consisting of halo, C1-C3alkyl, C1-C3haloalkyl and C1-C3 alkoxy;
Q is selected from the group consisting of:- (Formula Removed)
wherein
A1 is selected from the group consisting of O, C(O), S, SO, SO2 and (CReRf)q; q = 0,1 or 2;
R\Rb,Rc,Rd,Re and Rf are each independently selected from the group consisting of C1-C4alkyl which may be mono-, di- or tri-substituted by substituents selected from the group consisting of C1-C4alkoxy, halogen, hydroxy, cyano, hydroxycarbonyl, C1-C4alkoxycarbonyl, C1-C4alkylthio, C1-C4alkylsulfinyl, C1-C4alkylsulfonyl, C1-
C4alkylcarbonyl, phenyl and heteroaryl, it being possible for the phenyl and heteroaryl groups in turn to be mono-, di- or tri-substituted by substituents selected from the group consisting of C1-C4alkoxy, halogen, hydroxy, cyano, hydroxycarbonyl, C1-C4alkoxycarbonyl, C1-C4alkylsulfonyl and C1-C4haloalkyl, the substituents on the nitrogen in the heterocyclic ring being other than halogen; or
Ra,Rb,Rc,Rd,ReandRf are each independently selected from the group consisting of hydrogen, C1-C4alkoxy, halogen, hydroxy, cyano, hydroxycarbonyl, C1-C4alkoxycarbonyl, C1-C4alkylthio, C1-C4alkylsulfinyl, C1-C4alkylsulfonyl, C1-C4alkylcarbonyl, phenyl or heteroaryl, it being possible for the phenyl and heteroaryl groups in turn to be mono-, di- or tri-substituted by substituents selected from the group consisting of C1-C4alkoxy, halogen, hydroxy, cyano, hydroxycarbonyl, C1-C4alkoxycarbonyl, C1-C4alkylsulfonyl and C1-C4haloalkyl, the substituents on the nitrogen in the heterocyclic ring being other than halogen; or
Ra and Rb together form a 3- to 5-membered carbocyclic ring which may be substituted by C1-C4alkyl and may be interrupted by oxygen, sulfur, S(O), SO2, OC(O),NRg or by C(O);or
Ra and Rc together form a C1-C3alkylene chain which may be interrupted by oxygen, sulfur, SO, S02, OC(O), NRh or by C(O); it being possible for that C1-C3alkylene chain in turn to be substituted by C1-C4alkyl;
Rg and Rh are each independently of the other C1-C4alkyl, C1-C4haloalkyl, C1-C4alkylsulfonyl, C1-C4alkylcarbonyl or C1-C4alkoxycarbonyl;
RJ is C1-C4alkyl;
Rj is selected from the group consisting of hydrogen, C1-C4 alkyl and C3-C6 cycloalkyl. In a preferred embodiment Rj is selected from the group consisiting of hydrogen, methyl and cyclopropyl.
R3 is selected from the group consisting of C1-C6alkyl, optionally substituted with halogen and/or C1-C3alkoxy; and C3-C6 cycloalkyl optionally substituted with halogen and/or C1-C3alkoxy.
R9 is selected from the group consisting of cyclopropyl, CF3 and i.-Pr,
R10is selected from the group consisting of hydrogen, I, Br, SR11, S(0)Rn, S(0)2Rn
and CO2R11.
R11 is C1-4 alkyl.
Halogen is, generally, fluorine, chlorine, bromine or iodine. The same correspondingly applies to halogen in the context of other definitions, such as haloalkyl or halophenyl.
Haloalkyl groups having a chain length of from 1 to 6 carbon atoms are, for example, fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, 2,2,2-trifluoroethyl, 2-fluoroethyl, 2-chloroethyl, pentafluoroethyl, l,l-difluoro-2,2,2-trichloroethyl, 2,2,3,3-tetrafluoroethyl and 2,2,2-trichloroethyl, heptafluoro-n-propyl and perfluoro-n-hexyl.
Suitable alkylenyl radicals include, for example CH2, CHCH3, C(CH3)2, CH2CHCH3, CH2CH(C2H5).
Suitable haloalkenyl radicals include alkenyl groups substituted one or more times by halogen, halogen being fluorine, chlorine, bromine or iodine and especially fluorine or chlorine, for example 2,2-difluoro-l-methylvinyl, 3-fluoropropenyl, 3-chloropropenyl, 3-bromopropenyl, 2,3,3-trifluoropropenyl, 2,3,3-trichloropropenyl and 4,4,4-trifluorobut-2-en-l-yl. Preferred C2-C6alkenyl radicals substituted once, twice or three times by halogen are those having a chain length of from 2 to 5 carbon atoms. Suitable haloalkylalkynyl radicals include, for example, alkylalkynyl groups substituted one or more times by halogen, halogen being bromine or iodine and, especially, fluorine or chlorine, for example 3-fluoropropynyl, 5-chloropent-2-yn-l-yl, 5-bromopent-2-yn-l-yl, 3,3,3-trifluoropropynyl and 4,4,4-trifluoro-but-2-yn-l-yl.
Preferred alkylalkynyl groups substituted one or more times by halogen are those having a chain length of from 3 to 5 carbon atoms.
Alkoxy groups preferably have a chain length of from 1 to 6 carbon atoms. Alkoxy is, for example, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy or tert-butoxy or a pentyloxy or hexyloxy isomer, preferably methoxy and ethoxy. Alkylcarbonyl is preferably acetyl or propionyl. Alkoxycarbonyl is, for example, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, n-butoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl or tert-butoxycarbonyl, preferably methoxycarbonyl, ethoxycarbonyl or tert-butoxycarbonyl.
Haloalkoxy is, for example, fluoromethoxy, difluoromethoxy, trifluoromethoxy, 2,2,2-trifluoroethoxy, 1,1,2,2-tetrafluoroethoxy, 2-fluoroethoxy, 2-chloroethoxy, 2,2-difluoroethoxy or 2,2,2-trichloroethoxy, preferably difluoromethoxy, 2-chloroethoxy or trifluoromethoxy.
Alkylthio groups preferably have a chain length of from 1 to 6 carbon atoms. Alkylthio is, for example, methylthio, ethylthio, propylthio, isopropylthio, n-butylthio, isobutylthio, sec-butylthio or tert-butylthio, preferably methylthio or ethylthio. Alkylsulfinyl is, for example, methylsulfinyl, ethylsulfinyl, propylsulfinyl, isopropylsulfinyl, n-butylsulfmyl, isobutylsulfinyl, sec-butylsulfinyl or tert-butylsulfinyl, preferably methylsulfinyl or ethylsulfinyl.
Alkylsulfonyl is, for example, methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, n-butylsulfonyl, isobutylsulfonyl, sec-butylsulfonyl or tert-butylsulfonyl, preferably methylsulfonyl or ethylsulfonyl.
Alkylamino is, for example, methylamino, ethylamino, n-propylamino, isopropylamino or a butylamino isomer. Dialkylamino is, for example, dimethylamino, methylethylamino, diethylamino, n-propylmethylamino, dibutylamino or diisopropylamino. Preference is given to alkylamino groups having a chain length of from 1 to 4 carbon atoms.
Cycloalkylamino or dicycloalkylamino is , for example cyclohexyl or dicyclopropylamino.
Alkoxyalkyl groups preferably have from 1 to 6 carbon atoms. Alkoxyalkyl is, for example, methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, n-propoxymethyl, n-propoxyethyl, isopropoxymethyl or isopropoxyethyl.
Alkylthioalkyl groups preferably have from 1 to 6 carbon atoms. Alkylthioalkyl is, for example, methylthiomethyl, methylthioethyl, ethylthiomethyl, ethylthioethyl, n-propylthiomethyl, n-propylthioethyl, isopropylthiomethyl, isopropylthioethyl, butylthiomethyl, butylthioethyl or butylthiobutyl.
Cycloalkyl groups preferably have from 3 to 6 ring carbon atoms and may be substituted by one or more methyl groups; they are preferably unsubstituted, for example cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl.
Phenyl, including phenyl as part of a substituent such as phenoxy, benzyl, benzyloxy, benzoyl, phenylthio, phenylalkyl, phenoxyalkyl or tosyl, may be in mono-or poly-substituted form, in which case the substituents may, as desired, be in the ortho-, meta- and/or para-position(s).
Heterocyclyl, for example, includes morpholinyl, tetrahydrofuryl.
Heteroaryl, including heteroaryl as part of a substituent such as heteroaryloxy, means a five or six member heteroaryl containing one to three heteroatoms, each independently selected from the group consisting of oxygen, nitrogen and sulphur. It should be understood that the heteroaryl component may be optionally mono or poly substituted. The term heteroaryl thus includes, for example, furanyl, thiopheneyl, thiazolyl, oxazolyl, isoxazolyl, thiazolyl, pyrazolyl, isothiazolyl, pyridyl, pyridazinyl, pyrazinyl, pyrimidinyl, triazolyl.
Compounds of Formula la or lb may contain asymmetric centres and may be present as a single enantiomer, pairs of enantiomers in any proportion or, where more than one asymmetric centre are present, contain diastereoisomers in all possible ratios.
Typically one of the enantiomers has enhanced biological activity compared to the other possibilities.
Similarly, where there are disubstituted alkenes, these may be present in E or Z form or as mixtures of both in any proportion.
Compounds of Formula la where R7 is hydroxyl may be in equilibrium with an alternative tautomeric form, for example in compounds of Formula lb where R8 is hydrogen. Similarly, Ql, Q5, Q6 or Q7 may be in equilibrium with alternative hydroxyl tautomeric forms. It should be appreciated that all tautomeric forms (single tautomer or mixtures thereof), racemic mixtures and single isomers are included within the scope of the present invention.
The skilled person will also appreciate that if n and/or m is 1 with regard to Formula la or lb to form the N-oxide men the nitrogen and oxygen will be charged accordingly (N* O").
In a preferred embodiment the herbicidal compound is of Formula Iaa.
(Formula Removed)
In a more preferred embodiment of the present invention Q is Ql, in particular wherein A1 is CReRf and wherein Ra, Rb, Rc, Rd, Re and Rf are hydrogen, and wherein q=l.
In another preferred embodiment of the present invention Q is Ql, wherein A1 is CReRf and wherein, Rb, Rd, Re and Rf are hydrogen, Ra and Rc together form an ethylene chain and wherein q = 1
In another preferred embodiment R2 is (i) haloalkyl, in particularly fluoroalkyl, and most preferably difluoromethyl or trifluoromethyl, or (ii) C1.3alkoxy-C1-3-haloalkyl, in particular C1-3alkoxy-C1-3-fluoroalkyl, most preferably methoxydifluoromethyl or 2-methoxy-l,l,-difluoroethyl.
In another preferred embodiment R5 is hydrogen.
In another preferred embodiment R6 is hydrogen or fluorine.
In another preferred embodiment R7 is selected from the group consisting of hydrogen, hydroxyl, halogen, C1-C6alkyl, C3-C6cycloalkyl, C1-C6haloalkyl, C1-C6 alkoxy, C1-C6 alkoxy-C2-C6-alkoxy, C1-C6-alkoxy-C1-C6 alkyl, C1-C6-alkoxy-C2-C6-alkoxy-C1-C6alkyl, C1-C6alkylamino, C1-C6dialkylamino, C2-C<5alkenylamino, C1-C6alkoxy-C2-C3-alkylamino, (C1-C6alkoxy-C2-C3-alkyl) -C1-C3-alkylamino,C3-C6 cycloalkylamino, C3-C6 cyclohaloalkylamino, C1-C3alkoxy-C3-C6 cycloalkylamino, C3-C6 alkynylamino and a dialkylamino group in which the substituents join to form a 4-6 membered ring, optionally containing oxygen, or optionally substituted by C1-C3-alkoxy or halogen, especially fluorine In an even more preferred embodiment R7 is selected from the group consisting of hydrogen, methyl, ethyl, 1-methylethyl, cyclopropyl, fluoromethyl, difluoromethyl, trifluoromethyl, 1-fluoroethyl, 1,1-difluoroethyl, 2,2-difluoroethyl, 1-fluoro-1-methylethyl, 2,2,2-trifluoroethyl, difluorochloromethyl, methoxy, ethoxy, methoxymethyl, methoxyethyl, ethoxyethoxy, ethoxyethoxymethyl, methoxyethoxy, methoxyethoxymethyl, (2-methoxyethyl)amino and (2-methoxyethyl)methylamino.
In another preferred embodiment R8 is selected from the group consisting of hydrogen, C1-C6alkyl, C1-C3alkoxyC1-C3alkylenyl and C1-C6haloalkyl.
The present invention also includes agronomically acceptable salts that the compounds of Formula I may form with amines (for example ammonia, dimethylamine and triethylamine), alkali metal and alkaline earth metal bases or quaternary ammonium bases. Among the alkali metal and alkaline earth metal hydroxides, oxides, alkoxides and hydrogen carbonates and carbonates used as salt formers, emphasis is to be given to the hydroxides, alkoxides, oxides and carbonates of lithium, sodium, potassium, magnesium and calcium, but especially those of sodium, magnesium and calcium. The corresponding trimethylsulfonium salt may also be used.
The compounds of Formula (la) or (lb) according to the invention can be used as herbicides by themselves, but they are generally formulated into herbicidal compositions using formulation adjuvants, such as carriers, solvents and surface-active agents (SFAs). Thus, the present invention further provides a herbicidal composition comprising a herbicidal compound according to any one of the previous claims and an agriculturally acceptable formulation adjuvant. The composition can be in the form of concentrates which are diluted prior to use, although ready-to-use compositions can also be made. The final dilution is usually made with water, but can be made instead of, or in addition to, water, with, for example, liquid fertilisers, micronutrients, biological organisms, oil or solvents.
For the avoidance of doubt, reference to compounds of Formula I below includes reference to compounds of either Formula (la) and (lb).
The herbicidal compositions generally comprise from 0.1 to 99 % by weight, especially from 0.1 to 95 % by weight, compounds of Formula I and from 1 to 99.9 % by weight of a formulation adjuvant which preferably includes from 0 to 25 % by weight of a surface-active substance.
The compositions can be chosen from a number of formulation types, many of which are known from the Manual on Development and Use of FAO Specifications for Plant Protection Products, 5th Edition, 1999. These include dustable powders (DP), soluble powders (SP), water soluble granules (SG), water dispersible granules (WG), wettable powders (WP), granules (GR) (slow or fast release), soluble concentrates (SL), oil miscible liquids (OL), ultra low volume liquids (UL), emulsifiable concentrates (EC), dispersible concentrates (DC), emulsions (both oil in water (EW) and water in oil (EO)), micro-emulsions (ME), suspension concentrates (SC), aerosols, capsule suspensions (CS) and seed treatment formulations. The formulation type chosen in any instance will depend upon the particular purpose envisaged and the physical, chemical and biological properties of the compound of Formula (I).
Dustable powders (DP) may be prepared by mixing a compound of Formula (I) with one or more solid diluents (for example natural clays, kaolin, pyrophyllite, bentonite, alumina, montmorillonite, kieselguhr, chalk, diatomaceous earths, calcium
phosphates, calcium and magnesium carbonates, sulphur, lime, flours, talc and other organic and inorganic solid carriers) and mechanically grinding the mixture to a fine powder.
Soluble powders (SP) may be prepared by mixing a compound of Formula (I) with one or more water-soluble inorganic salts (such as sodium bicarbonate, sodium carbonate or magnesium sulphate) or one or more water-soluble organic solids (such as a polysaccharide) and, optionally, one or more wetting agents, one or more dispersing agents or a mixture of said agents to improve water dispersibility/solubility. The mixture is then ground to a fine powder. Similar compositions may also be granulated to form water soluble granules (SG).
Wettable powders (WP) may be prepared by mixing a compound of Formula (I) with one or more solid diluents or carriers, one or more wetting agents and, preferably, one or more dispersing agents and, optionally, one or more suspending agents to facilitate the dispersion in liquids. The mixture is then ground to a fine powder. Similar compositions may also be granulated to form water dispersible granules (WG).
Granules (GR) may be formed either by granulating a mixture of a compound of Formula (I) and one or more powdered solid diluents or carriers, or from preformed blank granules by absorbing a compound of Formula (I) (or a solution thereof, in a suitable agent) in a porous granular material (such as pumice, attapulgite clays, fuller's earth, kieselguhr, diatomaceous earths or ground corn cobs) or by adsorbing a compound of Formula (I) (or a solution thereof, in a suitable agent) on to a hard core material (such as sands, silicates, mineral carbonates, sulphates or phosphates) and drying if necessary. Agents which are commonly used to aid absorption or adsorption include solvents (such as aliphatic and aromatic petroleum solvents, alcohols, ethers, ketones and esters) and sticking agents (such as polyvinyl acetates, polyvinyl alcohols, dextrins, sugars and vegetable oils). One or more other additives may also be included in granules (for example an emulsifying agent, wetting agent or dispersing agent).
Dispersible Concentrates (DC) may be prepared by dissolving a compound of Formula (I) in water or an organic solvent, such as a ketone, alcohol or glycol ether.
These solutions may contain a surface active agent (for example to improve water dilution or prevent crystallisation in a spray tank).
Emulsifiable concentrates (EC) or oil-in-water emulsions (EW) may be prepared by dissolving a compound of Formula (I) in an organic solvent (optionally containing one or more wetting agents, one or more emulsifying agents or a mixture of said agents). Suitable organic solvents for use in ECs include aromatic hydrocarbons (such as alkylbenzenes or alkylnaphthalenes, exemplified by SOLVESSO 100, SOLVESSO 150 and SOLVESSO 200; SOLVESSO is a Registered Trade Mark), ketones (such as cyclohexanone or methylcyclohexanone) and alcohols (such as benzyl alcohol, furfuryl alcohol or butanol), N-alkylpyrrolidones (such as N-methylpyrrolidone or N-octylpyrrolidone), dimethyl amides of fatty acids (such as Cg-C10o fatty acid dimethylamide) and chlorinated hydrocarbons. An EC product may spontaneously emulsify on addition to water, to produce an emulsion with sufficient stability to allow spray application through appropriate equipment.
Preparation of an EW involves obtaining a compound of Formula (I) either as a liquid (if it is not a liquid at room temperature, it may be melted at a reasonable temperature, typically below 70°C) or in solution (by dissolving it in an appropriate solvent) and then emulsifying the resultant liquid or solution into water containing one or more SFAs, under high shear, to produce an emulsion. Suitable solvents for use in EWs include vegetable oils, chlorinated hydrocarbons (such as chlorobenzenes), aromatic solvents (such as alkylbenzenes or alkylnaphthalenes) and other appropriate organic solvents which have a low solubility in water.
Microemulsions (ME) may be prepared by mixing water with a blend of one or more solvents with one or more SFAs, to produce spontaneously a thermodynamically stable isotropic liquid formulation. A compound of Formula (I) is present initially in either the water or the solvent/SFA blend. Suitable solvents for use in MEs include those hereinbefore described for use in in ECs or in EWs. An ME may be either an oil-in-water or a water-in-oil system (which system is present may be determined by conductivity measurements) and may be suitable for mixing water-soluble and oil-soluble pesticides in the same formulation. An ME is suitable for dilution into water, either remaining as a microemulsion or forming a conventional oil-in-water emulsion.
Suspension concentrates (SC) may comprise aqueous or non-aqueous suspensions of finely divided insoluble solid particles of a compound of Formula (I). SCs may be prepared by ball or bead milling the solid compound of Formula (I) in a suitable medium, optionally with one or more dispersing agents, to produce a fine particle suspension of the compound. One or more wetting agents may be included in the composition and a suspending agent may be included to reduce the rate at which the particles settle. Alternatively, a compound of Formula (I) may be dry milled and added to water, containing agents hereinbefore described, to produce the desired end product.
Aerosol formulations comprise a compound of Formula (I) and a suitable propellant (for example n-butane). A compound of Formula (I) may also be dissolved or dispersed in a suitable medium (for example water or a water miscible liquid, such as n-propanol) to provide compositions for use in non-pressurised, hand-actuated spray pumps.
Capsule suspensions (CS) may be prepared in a manner similar to the preparation of EW formulations but with an additional polymerisation stage such that an aqueous dispersion of oil droplets is obtained, in which each oil droplet is encapsulated by a polymeric shell and contains a compound of Formula (I) and, optionally, a carrier or diluent therefor. The polymeric shell may be produced by either an interfacial polycondensation reaction or by a coacervation procedure. The compositions may provide for controlled release of the compound of Formula (I) and they may be used for seed treatment. A compound of Formula (I) may also be formulated in a biodegradable polymeric matrix to provide a slow, controlled release of the compound.
The composition may include one or more additives to improve the biological performance of the composition, for example by improving wetting, retention or distribution on surfaces; resistance to rain on treated surfaces; or uptake or mobility of a compound of Formula (I). Such additives include surface active agents (SFAs), spray additives based on oils, for example certain mineral oils or natural plant oils (such as soy bean and rape seed oil), and blends of these with other bio-enhancing adjuvants (ingredients which may aid or modify the action of a compound of Formula (I)).
Wetting agents, dispersing agents and emulsifying agents may be SFAs of the cationic, anionic, amphoteric or non-ionic type.
Suitable SFAs of the cationic type include quaternary ammonium compounds (for example cetyltrimethyl ammonium bromide), imidazolines and amine salts.
Suitable anionic SFAs include alkali metals salts of fatty acids, salts of aliphatic monoesters of sulphuric acid (for example sodium lauryl sulphate), salts of sulphonated aromatic compounds (for example sodium dodecylbenzenesulphonate, calcium dodecylbenzenesulphonate, butylnaphthalene sulphonate and mixtures of sodium di-isopropyl- and tri-isopropyl-naphthalene sulphonates), ether sulphates, alcohol ether sulphates (for example sodium laureth-3-sulphate), ether carboxylates (for example sodium laureth-3-carboxylate), phosphate esters (products from the reaction between one or more fatty alcohols and phosphoric acid (predominately mono-esters) or phosphorus pentoxide (predominately di-esters), for example the reaction between lauryl alcohol and tetraphosphoric acid; additionally these products may be ethoxylated), sulphosuccinsmates, paraffin or olefine sulphonates, taurates and lignosulphonates.
Suitable SFAs of the amphoteric type include betaines, propionates and glycinates.
Suitable SFAs of the non-ionic type include condensation products of alkylene oxides, such as ethylene oxide, propylene oxide, butylene oxide or mixtures thereof, with fatty alcohols (such as oleyl alcohol or cetyl alcohol) or with alkylphenols (such as octylphenol, nonylphenol or octylcresol); partial esters derived from long chain fatty acids or hexitol anhydrides; condensation products of said partial esters with ethylene oxide; block polymers (comprising ethylene oxide and propylene oxide); alkanolamides; simple esters (for example fatty acid polyethylene glycol esters); amine oxides (for example lauryl dimethyl amine oxide); and lecithins.
Suitable suspending agents include hydrophilic colloids (such as polysaccharides, polyvinylpyrrolidone or sodium carboxymethylcellulose) and swelling clays (such as bentonite or attapulgite).
The composition of the present may further comprise at least one additional pesticide. For example, the compounds according to the invention can also be used in
combination with other herbicides or plant growth regulators. In a preferred embodiment the additional pesticide is a herbicide and/or herbicide safener. Examples of such mixtures are (in which T represents a compound of Formula I). I + acetochlor, I + acifluorfen, I + acifluorfen-sodium, I + aclonifen, I + acrolein, I + alachlor, I + alloxydim, I + ametryn, I + amicarbazone, I + amidosulfuron, I + aminopyralid, I + amitrole, I + anilofos, I + asulam, I + atrazine, I + azafenidin, I + azimsulfuron, I + BCPC, I + beflubutamid, I + benazolin, I + bencarbazone, I + benfluralin, I + benfuresate, I + bensulfuron, I + bensulfuron-methyl, I + bensulide, I + bentazone, I + benzfendizone, I + benzobicyclon, I + benzofenap, I + bifenox, I + bilanafos, I + bispyribac, I + bispyribac-sodium, I + borax, I + bromacil, I + bromobutide, I + bromoxynil, I + butachlor, I + butamifos, I + butralin, I + butroxydim, I + butylate, I + cacodylic acid, I + calcium chlorate, I + cafenstrole, I + carbetamide, I + carfentrazone, I + carfentrazone-ethyl, I + chlorflurenol, I + chlorflurenol-methyl, I + chloridazon, I + chlorimuron, I + chlorimuron-ethyl, I + chloroacetic acid, I + chlorotoluron, I + chlorpropham, I + chlorsulfuron, I + chlorthal, I + chlorthal-dimethyl, I + cinidon-ethyl, I + cinmethylin, I + cinosulfuron, I + cisanilide, I + clethodim, I + clodinafop, I + clodinafop-propargyl, I + clomazone, I + clomeprop, I + clopyralid, I + cloransulam, I + cloransulam-methyl, I + cyanazine, I + cycloate, I + cyclosulfamuron, I + cycloxydim, I + cyhalofop, I + cyhalofop-butyl,, I + 2,4-D, I + daimuron, I + dalapon, I + dazomet, I + 2,4-DB, I +1 + desmedipham, I + dicamba, I + dichlobenil, I + dichlorprop, I + dichlorprop-P, I + diclofop, I + diclofop-methyl, I + diclosulam, I + difenzoquat, I + difenzoquat metilsulfate, I + diflufenican, I + diflufenzopyr, I + dimefuron, I + dimepiperate, I + dimethachlor, I + dimethametryn, I + dimethenamid, I + dimetfienamid-P, I + dimethipin, I + dimethylarsinic acid, I + dinitramine, I + dinoterb, I + diphenamid, I + dipropetryn, I + diquat, I + diquat dibromide, I + dithiopyr, I + diuron, I + endothal, I + EPTC, I + esprocarb, I + ethalfluralin, I + ethametsulfuron, I + ethametsulfuron-methyl, I + ethephon, I + ethofumesate, I + ethoxyfen, I + ethoxysulfuron, I + etobenzanid, I + fenoxaprop-P, I + fenoxaprop-P-ethyl, I + fentrazamide, I + ferrous sulfate, I + flamprop-M, I + flazasulfuron, I + florasulam, I + fluazifop, I + fluazifop-butyl, I + fluazifop-P, I + fluazifop-P-butyl, I + fluazolate, I + flucarbazone, I + flucarbazone-sodium, I + flucetosulfuron, I + fluchloralin, I + flufenacet, I + flufenpyr, I + flufenpyr-ethyl, I + flumetralin, I + flumetsulam, I + flumiclorac, I + flumiclorac-pentyl, I + flumioxazin, I + flumipropin, I + fluometuron, I + fluoroglycofen, I + fluoroglycofen-ethyl, I +
fluoxaprop, I + flupoxam, I + flupropacil, I + flupropanate, I + flupyrsulfuron, I + flupyrsulfuron-methyl-sodium, I + flurenol, I + fluridone, I + flurochloridone, I + fluroxypyr, I + flurtamone, I + fluihiacet, I + fluthiacet-methyl, I + fomesafen, I + foramsulfuron, I + fosamine, I + glufosinate, I + glufosinate-ammonium, I + glyphosate, I + halosulfuron, I + halosulfuron-methyl, I + haloxyfop, I + haloxyfop-P, I + hexazinone, I + imazamethabenz, I + imazamethabenz-methyl, I + imazamox, I + imazapic, I + imazapyr, I + imazaquin, I + imazethapyr, I + imazosulfuron, I + indanofan, I + iodomethane, I + iodosulfuron, I + iodosulfuron-methyl-sodium, I + ioxynil, I + isoproturon, I + isouron, I + isoxaben, I + isoxachlortole, I + isoxaflutole, I + isoxapyrifop, I + karbutilate, I + lactofen, I + lenacil, I + linuron, I + mecoprop, I + mecoprop-P, I + mefenacet, I + mefluidide, I + mesosulfuron, I + mesosulfuron-methyl, I + mesotrione, I + metam, I + metamifop, I + metamitron, I + metazachlor, I + methabenzthiazuron, I + methazole, I + methylarsonic acid, I + methyldymron, I + methyl isothiocyanate, I + metolachlor, I + S-metolachlor, I + metosulam, I + metoxuron, I + metribuzin, I + metsulfuron, I + metsulfuron-methyl, I + molinate, I + monolinuron, I + naproanilide, I + napropamide, I + naptalam, I + neburon, I + nicosulfuron, I + n-methyl glyphosate, I + nonanoic acid, I + norflurazon, I + oleic acid (fatty acids), I + orbencarb, I + orthosulfamuron, I + oryzalin, I + oxadiargyl, I + oxadiazon, I + oxasulfuron, I + oxaziclomefone, I + oxyfluorfen, I + paraquat, I + paraquat dichloride, I + pebulate, I + pendimethalin, I + penoxsulam, I + pentachlorophenol, I + pentanochlor, I + pentoxazone, I + pethoxamid, I + phenmedipham, I + picloram, I + picolinafen, I + pinoxaden, I + piperophos, I + pretilachlor, I + primisulfuron, I + prirnisulfuron-methyl, I + prodiamine, I + profoxydim, I + prohexadione-calcium, I + prometon, I + prometryn, I + propachlor, I + propanil, I + propaquizafop, I + propazine, I + propham, I + propisochlor, I + propoxycarbazone, I + propoxycarbazone-sodium, I + propyzamide, I + prosulfocarb, I + prosulfuron, I + pyraclonil, I + pyraflufen, I + pyraflufen-ethyl, I + pyrasulfotole, I + pyrazolynate, I + pyrazosulfuron, I + pyrazosulfuron-ethyl, I + pyrazoxyfen, I + pyribenzoxim, I + pyributicarb, I + pyridafol, I + pyridate, I + pyriftalid, I + pyriminobac, I + pyriminobac-methyl, I + pyrimisulfan, I + pyrithiobac, I + pyrithiobac-sodium, I + pyroxasulfone, I + pyroxsulam, I + quinclorac, I + quinmerac, I + quinoclamine, I + quizalofop, I + quizalofop-P, I + rimsulfuron, I + sethoxydim, I + siduron, I + simazine, I + simetryn, I + sodium chlorate, I + sulcotrione, I + sulfentrazone, I + sulfometuron, I + sulfometuron-methyl, I + sulfosate, I +
sulfosulfuron, I + sulfuric acid, I + tebuthiuron, I + tefuryltrione, I + tembotrione, I +
tepraloxydim, I + terbacil, I + terbumeton, I + terbuthylazine, I + terbutryn, I +
thenylchlor, I + thiazopyr, I + thifensulfuron, I + thiencarbazone, I + thifensulfuron-
methyl, I + thiobencarb, I + topramezone, I + tralkoxydim, I + tri-allate, I +
triasulfuron, I + triaziflam, I + tribenuron, I + tribenuron-methyl, I + triclopyr, I +
trietazine, I + trifloxysulfuron, I + trifloxysulfuron-sodium, I + trifluralin, I +
triflusulfuron, I + trifiusulfuron-methyl, I + trihydroxytriazine, I + trinexapac-ethyl, I
+ tritosulfuron, I + [3-[2-chloro-4-fluoro-5-(l-methyl-6-trifluoromethyl-2,4-dioxo-
l,23,4-tetrahydropyrimidin-3-yl)phenoxy]-2-pyridyloxy]acetic acid ethyl ester (CAS
RN 353292-31-6), I + 4-hydroxy-3-[[2-[(2-methoxyethoxy)methyl]-6-(trifluoro-
methyl)-3-pyridinyl]carbonyl]-bicyclo[3.2.1]oct-3-en-2-one (CAS RN 352010-68-5),
and I + 4-hydroxy-3-[[2-(3-methoxypropyl)-6-(difluoromethyl)-3-
pyridinyl]carbonyl]-bicyclo[3.2.1]oct-3-en-2-one. The compounds of the present invention may also be combined with herbicidal compounds disclosed in WO06/024820 and/or WO07/096576.
The mixing partners of the compound of Formula I may also be in the form of esters or salts, as mentioned e.g. in The Pesticide Manual, Fourteenth Edition, British Crop Protection Council, 2006.
The compound of Formula I can also be used in mixtures with other agrochemicals such as fungicides, nematicides or insecticides, examples of which are given in The Pesticide Manual.
The mixing ratio of the compound of Formula I to the mixing partner is preferably from 1:100 to 1000:1.
The mixtures can advantageously be used in the above-mentioned formulations (in which case "active ingredient" relates to the respective mixture of compound of Formula I with the mixing partner).
The compounds of Formula I according to the invention can also be used in combination with one or more safeners. Likewise, mixtures of a compound of Formula I according to the invention with one or more further herbicides can also be used in combination with one or more safeners. The safeners can be AD 67 (MON 4660), benoxacor, cloquintocet-mexyl, cyprosulfamide (CAS RN 221667-31-8), dichlormid, fenchlorazole-ethyl, fenclorim, fluxofenim, furilazole and the corresponding R isomer, isoxadifen-ethyl, mefenpyr-diethyl, oxabetrinil, and N-
isopropyl-4-(2-methoxy-benzoylsulfamoyl)-benzamide (CAS# RN 221668-34-4). Particularly preferred are mixtures of a compound of Formula I with cyprosulfamide, isoxadifen-ethyl and/or cloquintocet-mexyl.
The safeners of the compound of Formula I may also be in the form of esters or salts, as mentioned e.g. in The Pesticide Manual, 14th Edition (BCPC), 2006. The reference to cloquintocet-mexyl also applies to a lithium, sodium, potassium, calcium, magnesium, aluminium, iron, ammonium, quaternary ammonium, sulfonium or phos-phonium salt thereof as disclosed in WO 02/34048, and the reference to fenchlorazole-ethyl also applies to fenchlorazole, etc.
Preferably the mixing ratio of compound of Formula I to safener is from 100:1 to 1:10, especially from 20:1 to 1:1.
The mixtures can advantageously be used in the above-mentioned formulations (in which case "active ingredient" relates to the respective mixture of compound of Formula I with the safener).
The present invention still further provides a method of selectively controlling weeds at a locus comprising crop plants and weeds, wherein the method comprises application to the locus of a weed controlling amount of a composition according to the present invention. 'Controlling' means killing, reducing or retarding growth or preventing or reducing germination. Generally the plants to be controlled are unwanted plants (weeds). 'Locus' means the area in which the plants are growing or will grow.
The rates of application of compounds of Formula I may vary within wide limits and depend on the nature of the soil, the method of application (pre- or post-emergence; seed dressing; application to the seed furrow; no tillage application etc.), the crop plant, the weed(s) to be controlled, the prevailing climatic conditions, and other factors governed by the method of application, the time of application and the target crop. The compounds of Formula I according to the invention are generally applied at a rate of from 10 to 2000 g/ha, especially from 50 to 1000 g/ha.
The application is generally made by spraying the composition, typically by tractor mounted sprayer for large areas, but other methods such as dusting (for powders), drip or drench can also be used.
Useful plants in which the composition according to the invention can be used include crops such as cereals, for example barley and wheat, cotton, oilseed rape, sunflower, maize, rice, soybeans, sugar beet, sugar cane and turf. Maize is particularly preferred.
Crop plants can also include trees, such as fruit trees, palm trees, coconut trees or other nuts. Also included are vines such as grapes, fruit bushes, fruit plants and vegetables.
Crops are to be understood as also including those crops which have been rendered tolerant to herbicides or classes of herbicides (e.g. ALS-, GS-, EPSPS-, PPO-, ACCase- and HPPD-inhibitors) by conventional methods of breeding or by genetic engineering. An example of a crop that has been rendered tolerant to imidazolinones, e.g. imazamox, by conventional methods of breeding is Clearfield® summer rape (canola). Examples of crops that have been rendered tolerant to herbicides by genetic engineering methods include e.g. glyphosate- and glufosinate-resistant maize varieties commercially available under the trade names RoundupReady® and LibertyLink®.
In a preferred embodiment the crop plant is rendered tolerant to HPPD-inhibitors via genetic engineering. Methods of rending crop plants tolerant to HPPD-inhibitors are known, for example from WO0246387. Thus in an even more preferred embodiment the crop plant is transgenic in respect of a polynucleotide comprising a DNA sequence which encodes an HPPD-inhibitor resistant HPPD enzyme derived from a bacterium, more particularly from Pseudomonas fluorescens or Shewanella colwelliana, or from a plant, more particularly, derived from a monocot plant or, yet more particularly, from a barley, maize, wheat, rice, Brachiaria, Chenchrus, Lolium, Festuca, Setaria, Eleusine, Sorghum oxAvena species.
Crops are also to be understood as being those which have been rendered resistant to harmful insects by genetic engineering methods, for example Bt maize (resistant to European corn borer), Bt cotton (resistant to cotton boll weevil) and also Bt potatoes (resistant to Colorado beetle). Examples of Bt maize are the Bt 176 maize hybrids of NK® (Syngenta Seeds). The Bt toxin is a protein that is formed naturally by Bacillus thuringiensis soil bacteria. Examples of toxins, or transgenic plants able to synthesise such toxins, are described in EP-A-451 878, EP-A-374 753, WO 93/07278, WO 95/34656, WO 03/052073 and EP-A-427 529. Examples of transgenic plants comprising one or more genes that code for an insecticidal resistance and express one
or more toxins are KnockOut® (maize), Yield Gard® (maize), NuCOTIN33B® (cotton), Bollgard® (cotton), NewLeaf® (potatoes), NatureGard® and Protexcta®. Plant crops or seed material thereof can be both resistant to herbicides and, at the same time, resistant to insect feeding ("stacked" transgenic events). For example, seed can have the ability to express an insecticidal Cry3 protein while at the same time being tolerant to glyphosate.
Crops are also to be understood to include those which are obtained by conventional methods of breeding or genetic engineering and contain so-called output traits (e.g. improved storage stability, higher nutritional value and improved flavour).
Other useful plants include turf grass for example in golf-courses, lawns, parks and roadsides, or grown commercially for sod, and ornamental plants such as flowers or bushes.
The compositions can be used to control unwanted plants (collectively, 'weeds'). The weeds to be controlled may be both monocotyledonous species, for example Agrostis, Alopecurus, Avena, Bromus, Cyperus, Digitaria, Echinochloa, Lolium, Monochoria, Rottboellia, Sagittaria, Scirpus, Setaria, Sida and Sorghum, and dicotyledonous species, for example Abutilon, Amaranthus, Chenopodium, Chrysanthemum, Galium, Ipomoea, Nasturtium, Sinapis, Solanum, Stellaria, Veronica, Viola and Xanthium. Weeds can also include plants which may be considered crop plants but which are growing Outside a crop area ('escapes'), or which grow from seed left over from a previous planting of a different crop ('volunteers'). Such volunteers or escapes may be tolerant to certain other herbicides. The compounds of the present invention can be prepared using the following methods.
The preparation of compounds Formula 1(a) or 1(b)
(Formula Removed)
where Q is selected from Ql and Q5 is carried out analogously to known processes (for example those described in WO97/46530, EP0353187 and US 6,498,125) and comprises reacting a compound of the Formula 2a or 2b
(Formula Removed)
where Formula 2a and Formula 2b retain the definitions R2, R5, R6, R7, R8, X, n and m of Formulae la and lb and R12 is a suitable leaving group, for example a halogen atom, such as chlorine, or an alkoxy or aryloxy group, such as 4-nitrophenoxy, in an inert organic solvent, such as dichloromethane or acetonitrile, in the presence of a base, such as triethylamine, with compounds
(Formula Removed)
wherein
A1 and R\ Rb, Rc, Rd, Re, Rf and R1 are as defined previously;
to give compounds of the Formula 3a ,3b, 4a, 4b
(Formula Removed)
where Formulae 3a,3b,4a,4b retain the definitions of Formula 2a and 2b.
Alternatively, esters 3a, 3b, 4a, 4b may be produced from compounds of Formula 2a, 2b where R12 is a leaving group produced by reacting a carboxylic acid of Formula 2a, 2b where R12 is hydroxy with an activating reagent, such as N,N'-dicyclohexylcarbodiimide, in a suitable solvent, such as acetonitrile. Esters 3a,3b,4a,4b may be rearranged using catalysts, such as 4-dimethylaminopyridine, or acetone cyanhydrin, or a metal cyanide salt, such as sodium cyanide, in the presence of a suitable base, such as triethylamine, to give compounds of Formula la or lb. It is advantageous to have a dehydrating agent, such as molecular sieves, present in the reaction medium to ensure any water initially present in the solvent or associated with the other components of the reaction mixture is prevented from causing any unwanted hydrolysis of intermediates.
Scheme 1 (Secheme Removed)
[l,8]Naphthyridine-3-carboxylic acid derivatives of Formula 2a or 2b may be prepared from carboxylic acids, for example by reaction with a suitable halogenating agent, such as oxalyl chloride, in a suitable inert solvent, such as dichloromethane, to generate the corresponding carboxylic acid chlorides. These derivatives may in turn be reacted with, for example, 4-nitrophenol and a suitable base, such as triethylamine, in an inert solvent, such as dichloromethane, to generate the corresponding 4-nitrophenyl esters.
By way of illustration as shown in Scheme 2, [l,8]naphthyridine-3-carboxylic acid esters of Formula 5a may be obtained from 2-amino-3-formylpyridines, analogous to methods described in the literature [/. Org. Chem. 1990, 55,4744-4750; Indian
Journal of Chemistry, Section B; Organic Chemistry including Medicinal Chemistry (2006), 45B(4), 1051-1053; Indian Journal of Chemistry, Section B;Organic Chemistry including Medicinal Chemistry (2004), 43B(4), 897-900; J. Org. Chem. (1993), 58(24), 6625-6628; J. Chem. Soc.Org. (1966), (3), 315-321].
Scheme 2
(Secheme Removed)The required P-ketoesters are either commercially available or may be prepared analogously to methods described in the literature.
The required 2-amino-3-formyl pyridines are either commercially available or may be prepared by methods described in the literature [for example J. Org. Chem. 1983, 48, 3401-3408 and J. Org. Cliem. 1990, 55,4744-4750] or by analogous methods. By way of illustration as shown in Scheme 3, optionally substituted 2-aminopyridines may be JV-acylated, for example with a suitable acylating reagent, such as acetyl chloride or pivaloyl chloride, and a suitable base, such as triethylamine, optionally with a suitable acylation catalyst such as 4-dimethylaminopyridine, in an inert solvent, such as dichloromethane, to give the corresponding N-(pyridin-2-yl)amides. Analogous to methods described in the literature, these amides may in turn be reacted with a strong base, such as t.butyl lithium and then a formyl transfer agent, such as N,N-dimethylformamide or N-formyl-N-methylaniline, to give the corresponding N-(3-formylpyridin-2-yl)amides. The required 2-amino-3-formylpyridines can be obtained by hydrolysis of these amides using, for example, aqueous hydrochloric acid heated under reflux for 1 to 24 hours.
Scheme 3 (Secheme Removed)
With regard to scheme 3, R'" is for example, C1-Cs alkyl.
In another aspect, as shown in Scheme 4,2-amino-3-formylpyridines may be further transformed into 2-arnino-3-formyl-5-halopyridines using a halogenating agent, such as N-bromosuccinimide, in a suitable solvent, such as acetonitrile. Such 2-amino-3-formyl-5-halopyridines can be used to prepare naphthyridines (as shown in Scheme 2).
Scheme 4
(Secheme Removed)
As shown in Scheme 5, [l,8]naphthyridine-3-carboxylic acid esters of Formula 5a may be conveniently hydrolysed to the corresponding carboxylic acids using standard procedures, for example using aqueous sodium hydroxide and an inert co-solvent such as ethanol, or lithium hydroxide in aqueous tetrahydrofuran.
Scheme 5
(Secheme Removed)
As shown in Scheme 6, [l,8]naphlhyridine-3-carboxylic acid esters of Formula 5a may be conveniently converted to the corresponding 8-oxides using a suitable oxidant such as a peracid, for example per-trifluoroacetic acid generated from urea hydrogen peroxide complex and trifluoroacetic acid anhydride.
The 8-oxides generated may be further reacted with a suitable acid halide reagent, such as phosphoryl chloride, optionally with a suitable base, such as triethylamine, in a suitable solvent, such as dichloromethane or 1,2-dichloroethane, at 20°C to 100°C to give the 7-halo or 5-halo derivatives or a mixture of both halogen regioisomers depending on the reaction conditions.
Scheme 6(Secheme Removed)
With regard to scheme 6, R1 is, for example, C1-C4 alkyl.
As shown in Scheme 7,5-halo-[l,8]naphthyridines and 7-halo[l,8]naphthyridines may be further transformed into additional naphthyridines useful for preparing compounds of Formula la or lb. For example, when R5 is hydrogen or methyl and R7 is a chlorine atom, the chlorine may be displaced by an alkoxide reagent, such as sodium ethoxide, in a suitable solvent, such as tetrahydrofuran or N,N-dimethylfonnamide or an alcohol, such as ethanol, to generate the corresponding 7-alkoxy[l,8]naphthyridine. Similarly, 7-halo[l,8]naphthyridines may be reacted with an amine, such as morpholine, in a suitable solvent, such as tetrahydrofuran, to generate the corresponding 7-alkylamino[l,8]naphthyridine or 7-dialkylamino[l,8]naphthyridine. Additionally, 5-halo- or 7-halo- [l,8]naphthyridines,
such as 7-chloro[l,8]naphthyridines, and 5-alkoxy- or 7-alkoxy-[l,8]naphthyridines, such as 7-ethoxy[l,8]naphthyridines, may be converted to 5-hydroxy- or 7-hydroxy-[l,8]naphthyridines, for example by hydrolysis under acidic conditions, such as heating with aqueous hydrochloric acid. Such reactions may be conducted at temperatures from 20°C to 150°C, for example in a microwave oven. Additionally, 5-hydroxy or 7-hydroxy[l,8]naphthyridines may be transformed to the corresponding haloalkanesulfonate esters of [l,8]naphthyridines, such as 7-trifluorome(hanesulfonyloxy[l,8]naphthyridines, with a suitable acylation agent, such as trifluoromethane sulfonic anhydride, and a suitable base, such as triethylamine, in a suitable solvent, such as dichloromethane. In another aspect, 5-halo or 7-halo [l,8]naphthyridines, such as 7-chloro[l,8]naphthyridines, or 5- or 7-haloalkanesulfonate esters of [l,8]naphthyridines, such as 7-trifluoromethanesulfonyloxy[l,8]naphthyridines, may be reacted with a boronic acid reagent, such as methyl boronic acid, in the presence of a palladium catalyst, such as palladium acetate, and a suitable base such as potassium phosphate and a suitable palladium ligand, such as dicyclohexyl-(2',6'-dimethoxybiphenyl-2-yl) phosphane, to generate 5-alkyl or 7-alkyl[l,8]naphthyridine derivatives.
Scheme 7
(Secheme Removed)
In another aspect as shown in Scheme 8, [l,8]naphthyridine esters in which R7 is hydrogen may be reacted with an alkyl a-ketoacid, such as pyruvic acid, under catalysis by silver (I) salts, such as silver nitrate, in the presence of an oxidant, such as ammonium persulfate, and an acid, such as trifluoroacetic acid or sulfuric acid, in water and an inert co-solvent, such as dichloromethane, to generate 7-alkylcarbonyl[l,8]naphthyridine esters.
Scheme 8
(Secheme Removed) With regard to Scheme 8, R'"" is, for example, C1-C5 alkyl or C1-C3alkoxy-C1-C5-alkyl.
Alternatively as shown in Scheme 9,7-acetyl[l,8]naphthyridines may be produced by reacting 7-halo[l,8]naphthyridines or 7-trifluoromefhanesulfonyloxy[l,8] naphthyridines with a suitable organotin reagent, such as (1-ethoxyvinyl)tributylstannane, in the presence of a palladium catalyst, such as bis-(triphenylphosphine)palladium dichloride, heated in a suitable solvent, such as toluene, to generate the corresponding 7-(l-alkoxyvinyl)-[l,8]naphthyridines. 7-(l-Alkoxyvinyl)-[l,8]naphthyridines when treated with a suitable acid, such as aqueous hydrochloric acid, provide the corresponding 7-acetyl[l,8]naphthyridines.
Scheme 9
(Secheme Removed)
With regard to Scheme 9, R1 is, for example, C1-C4 alkyl and R' is, for example, C1-C6 alkyl.
As shown in Scheme 10,7-alkylcarbonyl[l,8]naphthyridines may be treated with a
suitable fluorinating agent, such as diethylaminosulfur trifluoride, in a suitable inert
solvent, such as dichloromethane, to provide 7(l,l-difluoroalkyl)[l,8]naphthyridines.
Alternatively, 7-alkylcarbonyl-[l,8]naphthyridines may be reacted with an
organometallic reagent, such as methyl magnesium chloride, in an inert solvent, such
as tetrahydrofuran, to generate 7(l-alkyl-l-hydroxyalkyl)-[l,8]naphthyridines.
In another aspect, 7-alkylcarbonyl-[l,8]naphthyridines may be reduced with a suitable
reducing agent, such as sodium borohydride, in a suitable solvent, such as ethanol, to
provide 7-(l-hydroxyalkyl)[l,8]naphthyridines.
Both 7(l-hydroxyalkyl)[l,8]naphthyridines and 7(l-alkyl-l-
hydroxyalkyl)[l,8]naphthyridines may be treated with a suitable fluorinating agent,
such as diethylaminosulfur trifluoride, to provide 7-(l-fluoroalkyl)[l,8]naphthyridines and 7-(l-alkyl-l-fluoroalkyl)[l,8]naphthyridines respectively.
Scheme 10
(Secheme Removed)With regard to Scheme 10, R? and R?? are, foi example, independently hydrogen or C1-C4 alkyl.
Using processes known to those skilled in the art as shown in Scheme 11, a compound where R6 is halogen, such as bromine, may be transformed to a compound where R6 is amino, using an amino transfer reagent, such as dibenzophenone imine, and a suitable palladium catalyst, such as palladium acetate, and a suitable palladium ligand, such as 4,5-bis-(diphenylphosphoranyl)-9,9-dimethyl-9H-xanthene, with a suitable base, such as cesium carbonate.
Scheme 11
(Secheme Removed)
As shown in Scheme 12,6-amino-[l,8]naphthyridines may be transformed into a 6-fluoro-l,8]naphthyridine via diazonium salts that are subsequently decomposed to generate the required fluoronaphthyridines either after isolation of the salt or in situ using procedures known to those skilled in the art.
Scheme 12
(Secheme Removed)
Naphthyridine diazonium salts may be prepared from aminonaphthyridines with sodium nitrite or an alkyl nitrite ester, such as t.-butyl nitrite, in anhydrous or aqueous hydrogen fluoride or hydrogen fluoride-pyridine complex or hydrogen fluoride-triethylamine complex and converting the intermediate diazonium salt or diazoether to the fluoro derivative using procedures known to those skilled in the art, for example by warming the diazo intermediate to its decomposition temperature. Alternatively, the diazonium salt may be fluoro-dediazotised in a suitable reactor using a source of ultra-violet radiation to produce the corresponding 7-fluoro[l,8]naphthyridine. Additionally, compound III in aqueous tetrafluoroboric acid may be treated with an aqueous solution of an alkaline metal nitrite salt, such as sodium nitrite, to generate a diazonium tetrafluoroborate salt that may be isolated, for example by filtration. The dry diazonium salt may be heated directly or in a suitable inert solvent, such as n-octane, toluene or 1,2-dichlorobenzene to decompose the salt to the corresponding 7-fluorof 1,8]naphthyridine.
In another aspect of the invention as shown in Scheme 13, compounds of Formula la where R7 is an alkoxy group, such as ethoxy, may be heated, for example using a microwave oven, with an acid, such as hydrochloric acid, and a suitable solvent such as ethanol, at 80-130°C to generate compounds of Formula lb where R8 is hydrogen. In solution, 7-hydroxy-[l,8]naphthyridines are in equilibrium with their corresponding 7-oxo-7,8-dihydro[l,8]naphthyridine tautomers. Depending on the reaction conditions employed, these tautomers may be alkylated to give mainly 7-0-alkyl or 8-N-alkyl products or mixtures of both.
Scheme 13
(Secheme Removed)Furthermore, the compounds depicted in Scheme 14 can be obtained as shown. Providing R8 is not hydrogen, the starting compounds may be reacted with a suitable acylation agent, such as isobutyryl chloride, in the presence of a suitable base, such as triethylamine or potassium carbonate, in a suitable inert solvent, such as tetrahydrofuran or dichloromethane, at temperatures from 0°C to 150°C.
Schemel4
(Secheme Removed)
In another aspect of the invention as shown in Scheme 15, compounds of Formula la, where Q is Q6 may be obtained by treating compounds of Formula la where Q is Q2 or Q3 with a suitable base, such as triethylamine, in an inert solvent, such as dichloromethane or toluene, at 20°C to 100°C. The salt of the required product obtained is subsequently treated with a suitable acid, such as hydrochloric acid, to provide the corresponding [l,8]naphthyridine cyanodiketone.
Scheme 15 (Secheme Removed)
In another aspect of the invention as shown in Scheme 16, a [l,8]naphthyridin-3-yl propan-l,3-dione can be reacted with a N,N-dialkylformamide dialkylacetal reagent, such as N,N-dimethylformamide dimethyl acetal, in a suitable solvent, such as tetrahydrofuran, optionally with an organic acid, such as acetic acid, at temperatures between 20°C and 150°C to produce a 2-[l-dialkylaminomethylidene] [l,8]naphthyridin-3-yl propan-l,3-dione. Such a compound can be treated with hydroxylamine in a suitable solvent, such as ethanol, at temperatures from 20°C to 150°C to generate compounds as indicated where Q is Q2 or Q3. [l,8]naphthyridin-3-yl propan-l,3-diones may be prepared by reacting a suitable compound with a t. butyl P-ketoester derivative using procedures analogous to those known to those skilled in the art.
Scheme 16
(Secheme Removed)In another aspect of the invention as shown in Scheme 17, a compound of Formula la where Q = Q7 may be prepared from a magnesium salt of a [l,8]naphthyridin-3-yl propan-l,3-dione in a suitable solvent, such as tetrahydrofuran, and a suitable acylating agent, such as cyclopropanecarboxylic acid chloride, at temperatures from 25°C to 100°C. The required [l,8]naphthyridine triketone derivative is obtained by acidification of triketone salt.
Scheme 17
(Secheme Removed)
In a further aspect of the invention as shown in Scheme 18, compounds of Formula la or lb where n = m = 0 may be oxidised to compounds of Formula la or lb where n or m (but not both) equal 1 using a suitable oxidant such as a peracid, for example pertrifluoroacetic acid generated using urea hydrogen peroxide complex and trifluoroacetic anhydride, to produce compounds of Formula la or lb, where n or m (but not both) equal 1.
Scheme 18
(Secheme Removed)In a further aspect of the invention as shown in Scheme 19, certain substituted naphthyridine esters may be obtained from certain naphthyridine ester N-oxides and optionally substituted alkenyl, optionally substituted aryl or optionally substituted heteroarylboronic acids by heating from 30-200°C, typically (80-150) °C, in a suitable inert solvent, for example toluene, and optionally dehydrating the intermediate product with a suitable reagent, such as an acid, for example para-toluene sulfonic acid(PTSA).
Scheme 19
(Secheme Removed)In a further aspect of the invention as shown in Scheme 20, certain substituted naphthyridine esters may be obtained from certain naphthyridine ester N-oxides and optionally substituted alkyl or cycloalkyl Grignard reagents, for example isopropylmagnesium chloride or cyclopropylmagnesium bromide or allyl magnesium chloride, in a suitable inert solvent or mixture of solvents, for example tetrahydrofuran, N-methylpyrrolidin-2-one typically under an inert atmosphere and anhydrous conditions and optionally dehydrating the intermediate product with a suitable reagent, such as an acid anhydride, for example acetic anhydride.
Scheme 20
(Secheme Removed)
Scheme 21
In a further aspect of the invention as shown in Scheme 21, certain alkoxyfluoroalkylsubstituted naphthyridine esters may be obtained from certain haloalkylnaphthyridine esters and alcohols in the presence of a silver salt, such as silver tetrafluoroborate, at a temperature between 30°Cand 150°C, typically at 60°C.
(Secheme Removed)Abbreviations as used in the following examples are as follows: s= singlet, d=doublet, t= triplet, m= multiplet, bs = broad signal, dd = double doublet, dt = double triplet, td = triple doublet and dq = double quartet.
Example 1
Preparation of 2-(2-trifluoromethyl[1,8]naphthyridine-3-carbony)- cyclohexane-1,3-
dione
Stage 1
Preparation of ethyl 2-trifluoromethyl[1,8]naphthyridine-3-carboxylate
A mixture of 2-amino-pyridine-3-carboxaldehyde (30.0g), ethyl 4,4,4-
trifluoroacetoacetate (37ml) and piperidine (25ml) in ethanol (100ml) were heated to
reflux with stirring for 2 hours, allowed to cool to ambient temperature then chilled to
0°C. The colourless solid that precipitated was filtered from solution, washed with a
small volume of cold diethyl ether and sucked to dryness to give the required product
as a colourless solid, 45.5 g. lH NMR (CDC13) δ: 9.33(1H, m), 8.77(1H, s), 8.38(1H,
dd), 7.70(1H, m), 4.50(2H, q), 1.45(3H, t).
The following compounds were prepared in a similar procedure:
From 2-amino-6-methoxymethylpyridinyl-3-carboxaldehyde and ethyl 4,4,4-
trifluoroacetoacetate to give ethyl 2-trifiuoromethyl-7-methoxymethyl-[l,8]-
naphthyridine-3-carboxylate, red-brown solid, lH NMR (CDC13) δ: 8.75(1H, s), 8.37
(1H, d), 7.94(1H, d), 4.88(2H, s), 4.48 (2H, q), 3.55(3H, s), 1.45(3H, t).
From 2-amino-6-methylpyridinyl-3-carboxaldehyde and methyl 4-chloro-4,4-
difluoroacetoacetate to give methyl 2-chlorodifluoromethyl-7-methyl-[l,8]-
naphthyridine-3-carboxylate, solid, m.p. 134-137°C, lH NMR (CDC13) δ: 8.60(1H,
s), 8.21(1H, d), 7.55(1H, d), 4.02(3H,s), 2.90(3H, s).
From 2-amino-6-methylpyridinyl-3-carboxaldehyde and ethyl 4,4-difluoroacetoacetate to give ethyl 2-difluoromethyl-7-methyl-[l,8]-naphthyridine-3-carboxylate, solid, m.p. 112-114°C, lH NMR (CDC13) δ: 8.84(1H, s), 8.21(1H, d),7.52-7.54(lH, d), 7.30-7.56(lH, t), 4.46-4.52(2H, q), 2.88(3H, s), 1.45-1.49(3H,t). From 2-amino-6-methylpyridinyl-3-carboxaldehyde and methyl 4-methoxyacetoacetate to give methyl 2-methoxymethyl-7-methyl-[l,8]-naphthyridine-3-carboxylate, yellow solid, lH NMR (CDC13) δ: 8.64 (1H, s), 8.13 (1H, d), 7.44 (1H, d), 5.08 (2H, s), 3.93 (3H, s), 3.43 (3H, s), 2.84 (3H,s). Molecular ion: (MH)+ 247. Stage 2
Preparation of 2-trifluoromethyl-n.81-naphthyridine-3-carboxylic acid To a stirred solution of ethyl 2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate (25.0g) in ethanol (100ml) and water (35ml) was added sodium hydroxide (11.lg) at ambient temperature. The mixture was stirred for 6 hours, acidified with aqueous 2M hydrochloric acid and the solid that precipitated from solution was filtered from solution, sucked to dryness then finally dried under vacuum to give the required product as a colourless solid, 25g, containing some sodium chloride. 1H NMR (d6-DMSO) δ: 9.35(1H, m), 9.18(1H, s), 8.77(1H, dd), 7.94(1H, m).
Stage 3
To a stirred suspension of 2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid (2.0g) and cyclohexane-l,3-dione (l.llg) in dry acetonitrile (60ml) was added in portions iV*,iV'-dicyclohexylcarbodiimide (1.87g) at ambient temperature. The mixture was stirred for 6 hours, the insolubles were filtered from solution and triethylamine (1.75ml) and acetone cyanhydrin (0.14ml) were added to the filtrate. The solution was stirred at ambient temperature for 16 hours then evaporated under reduced pressure. The residual solid was purified by chromatography (silica, (toluene: dioxane, ethanol: triethylamine:water, ratio by volume 20:8:4:4:1) to give the triethylamine salt of the required product. 1H NMR (CDCl3) δ 9.13(1H, dd), 8.18(1H, dd), 8.00(1H, s), 7.52(1H, dd), 3.20(6H, q), 2.40(4H, t), 1.95(2H, quintet), 1.30(9H, t).
The salt was washed with ethyl acetate, filtered then suspended in dichloromethane and acidified with aqueous 2M hydrochloric acid (5ml). The organic fraction was separated, washed with water (2x10ml), dried over magnesium sulfate then
evaporated under reduced pressure to give the required product as a pale yellow solid, 0.56g, m.p. 175-177°C.
1H NMR (d6-DMSO) δ: 9.29(1H, dd), 8.65(1H, s), 8.61(1H, dd), 7.86(1H, dd), 2.64-2.58(4H, m), 1.96(2H, quintet). Molecular ion: (MH)+ 337.
In a similar procedure to Example 1,2-trifluoromethyl-[l,8]-naphmyridine-3-carboxylic acid was reacted with 2-methyl-2,4-dihydropyrazol-3-one to give 2-methyl-4-(2-tiifluoromethyl-[l,8]-naphmyridine-3-carbony)-2,4-dihydropyrazol-3-one as a solid, lH NMR (D20) δ: 9.18(1H, d), 8.59(1H, s), 8.55(1H, dd), 7.80(1H, dd), 4.76(1H, s), 3.29(3H, s), Molecular ion: (M-H) 321.
In a similar procedure to Example 2-(l,l-difluoro-2-methoxyethyl)-l,6-fluoro-7-methyl-[l,8]-naphthyridine-3-carboxylic acid was reacted with 2-ethyl-2,4-dihydropyrazol-3-one to give 2-ethyl-4-[6-fluoro-2-(l,l-difluoro-2-methoxyethyl)-[l,8]-naphmyridine-3-carbony]- 2,4-dihydropyrazol-3-one, orange foamy solid, Molecular ion: (MH)+395, 1H NMR (CDC13) δ: 8.26(1H, s), 7.78-7.80(lH, d), 7.30(1H, s), 4.32-4.40(2H, t), 4.06-4.12(2H, q), 3.50(3H, s), 2.86(3H, d), 1.44-1.48(3H, t).
The following compounds were prepared in a similar procedure to Example 1, Stage 3 from 2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid and the corresponding ketones:
2-(2-trifluoromethyl-[l)8]-naphthyridine-3-carbony)-5-methylcyclohexane-l,3-dione, yellow solid, 1H NMR (CDC13) δ:16.64(1H, s), 9.28 (1H, dd), 8.27(1H, dd), 8.11(1H, s), 7.64(1H, dd), 2.87(1H, m), 2.56(1H, dd), 2.48(1H, m), 2.37-2.32(lH, m), 2.16(1H, d), 1.14<3H, d).
4-(2-trifluoromethyl-[l,8]-naphthyridine-3-carbony)-(2,2,6,6-tetramethylpyran-3,5-dione), pale yellow solid, 1H NMR (CDCl3): δ 16.75 (1H, s), 9.29-9.28 (1H, m), 8.30 (1H, dd), 8.2 (1H, s), 7.67 (1H, dd), 1.65 (6H, s,) 1.34 (6H, s).
6-(2-trifluoromethyl-[l,8]-naphthyridine-3-carbony)-(2,2,4,4,-tetramethylcyclohexane-l,3,5-trione), pale yellow solid, lH NMR (CDCl3), δ 17.21
(1H, s), 9.31 (1H, bs), 8.32 (1H, bd), 8.22 (1H, bs), 7.69 (1H, bs), 1.60 (6H, s) 1.30 (6H, s). Molecular ion: (MH)+407.
5-(2-trrifluoromethyl-[l,8]-naphthyridine-3-carbony)-spiro[2.5]octane-4,6-dione, brown solid, lH NMR (CDC13) δ:16.78(1H, s), 9.28-9.25(lH, m), 8.29-8.26(lH, m), 8.13(1H, s), 7.66-7.63(lH, m), 2.90(1H, t), 2.51(1H, t), 1.98-1.93(2H, m), 1.73(1H, q), 1.17-1.13(2H, m), 0.71(1H, q).
3-(2-trifluoromediyl-[l,8]-naphthyridine-3-carbony)-bicyclo[3.2.1]octane-2,4-dione, off-white solid, m.p. 189-191°C. 1H NMR
(CDCl3): 8 9.30 (1H, dd), 8.65 (1H, s), 8.62 (1H, dd), 7.86 (1H, dd), 2.91 (2H, bs), 2.07-2.16 (3H, m), 1.78-1.68 (3H, m).
From l-methylbicyclo[3.2.1]octane-2,4-dione (WO 2005105717), 3-(2-trrifluoromethyl-[l,8]-rmphthyridine-3-carbony)-l-methyl-bicyclo[3.2.1]octane-2,4-dione, pale yellow gum, 1H NMR (CD3OD): δ 9.23 (1H, double doublet), 8.58 (1H, double doublet), 8.50 (1H, s), 7.83 (1H, double doublet), 2.98 - 3.03 (1H, m), 2.34 - 2.42 (1H, m), 2.09 (1H, d), 1.81 - 2.03 (3H, m), 1.81 (1H, double doublet), 1.40 (3H, s).
From 6-methylbicyclo[3.2.1]octane-2,4-dione (WO 2005105717), 3-(2-trifluoromethyl-[l,8]-naphmyridine-3-carbony)-6-methyl-bicyclo[3.2.1]octane-2,4-dione, pale yellow gum, 1H NMR (CD3OD): δ 9.20 (1H, double doublet), 8.57 (1H, double doublet), 8.47 (1H, s), 7.80 (1H, double doublet), 2.44 - 2.53 (1H, m), 1.80 -1.91 (1H, m), 1.53 - 2.32 (5H, m), 1.06 (3H, d).
The following compounds were prepared in a similar procedure to Example 1, Stage 3 from cyclohexanel,3-dione and the corresponding naphthyridine carboxylic acids.
From 2-pentafluoroethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-(2-pentafluoroethylnaphthyridine-3-carbonyl)-cyclohexane-l,3-dione, colourless solid. lH NMR (CDC13) δ:16.67(1H, s), 9.31(1H, bs), 8.30(1H, m), 8.13(1H, m), 7.69(1H, m), 2.90(2H, m), 2.45(2H, m), 2.13(2H, m). Molecular ion: (M-H) 385.
From 6-chloro-2-trifluoromethylnaphthyridine-3-carboxylic acid, 2-(6-chloro-2-trifluoromethyl-[l,8]-naphthyridine-3-carbonyl)-cyclohexane-l,3-dione, maroon solid. lH NMR (CDC13) δ:16.55(1H, s), 9.16(1H, d), 8.23(1H, d), 8.02(1H, s), 2.85(2H, t), 2.42(2H, t), 2.08(2H, quintet). Molecular ion: (MH)+ 371. From 7-chloro-2-trifluoromethylnaphthyridine-3-carboxylic acid, 2-(7-chloro-2-trifluoromethyl-[l,8]-naphthyridine-3-carbonyl)-cyclohexane-l,3-dione, pale yellow solid. lH NMR (CDC13) δ: 8.19(1H, d), 8.10(1H, s), 7.64(1H, d), 2.85(2H, bs), 2.42(2H, bs), 2.08(2H, quintet) Molecular ion: (MH)+ 371.
From 2,7-bis (trifluoromethyl)-[l,8]-naphthyridine-3-carboxylic acid, 2-(2,7-bis(-trifluoromethyl)-[1,8]-naphthyridine-3-carbonyl)-cyclohexane-1,3-dione, pale yellow solid. 1H NMR(CDC13) δ: 8.19(1H, d), 8.10(1H, s), 7.64(1H, d), 2.85(2H, bs), 2.42(2H, bs), 2.08(2H, quintet) Molecular ion: (MH)+ 371.
Also as triemylamine salt: 1H NMR (CDC13) δ: 8.42(1H, d), 8.10(1H, s), 7.92(1H, d), 3.18 (6H, q), 2.52-2.48(4H, m), 2.02-1.95(2H, quintet). 1.30(9H, t), Molecular ion: (MH)+ 405.
From 2-difluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-(2-difluoromethyl-[l,8]-naphthyridine-3-carbony)-cyclohexane-l,3-dione
lH NMR (CDC13) δ:16.80(1H, s), 9.23(1H, dd), 8.25(1H, dd), 8.10(1H, s), 7.62(1H, dd), 6.87(1H, t), 2.10-2.06(4H, m), 1.29-1.25(2H, m). Molecular ion: (MH)+ 321.
From 2-difluoromethyl-7-methylnaphthyridine-3-carboxylic acid, 2-(2-difluoromethyl-7-methyl-[l,8]-naphmyridine-3-carbonyl)-cyclohexane-l,3-dione, gum. 1H NMR (CDC13) δ: 8.32-8.34(lH, d), 8.14(1H, s), 7.60-7.62(lH, d), 6.68-6.94(1H, t), 2.96(3H, s), 2.50-2.80(4H, broad s), 2.06-2.10(2H, t).
From 2-difluoromethyl-6-fluoro-7-methylnaphthyridine-3-carboxylic acid, 2-(2-difluoromethyl-6-fluoro-7-methyl-[l,8]-naphthyridine-3-carbonyl)-cyclohexane-l,3-dione, gum. 1H NMR (CDC13) δ: 8.02(1H, s), 7.76(1H, d), 6.83(1H, t), 2.43(3H, broad s), 2.07(2H, quintet).
From 2-chlorodifluoromethyl-6-fluoro-7-methymaphthyridine-3-carboxylic acid, 2-(2-chlorodifluoromethyl-6-fluoro-7-methyl-[l,8]-naphthyridine-3-carbonyl)-cyclohexane-l,3-dione, yellow solid. lH NMR (CDC13) δ: 7.97(1H, s), 7.74(1H, d), 2.84(3H, d), 2.83(2H, broad s), 2.42(2H, broad signal), 2.07(2H, quintet).
From 2-methyl-[l,8]-naphthyridine-3-carboxylic acid, 2-(2-methyl-[l,8]-naphthyridine-3-carbony)-cyclohexane-1,3-dione
1H NMR (CDCl3) δ: 9.39(1H, dd), 8.47(1H, dd), 8.03(1H, s), 7.74(1H, dd), 2.76(3H, s), 2.34-2.89(4H, m), 2.11(2H, quintet). Molecular ion: (M-H) 281.
From 7-(moipholm-4-yl)-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[(7-(morpholin-4-yl)-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-1,3-dione, yellow solid. lH NMR (CDCI3) δ: 7.89(1H, d, 7.82(1H, s), 7.10(1H, d), 3.90(4H, m), 3.84(4H, m), 2.80 (2H, bs), 2.44(2H, bs), 2.06(2H, quintet).
From 7-(6-fluoropyrid-3-yl)-2-trifluoromethyl-[l ,8]-naphthyridine-3-carboxylic acid,
2-[7-(6-fluoropyrid-3-yl)-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-
cyclohexane-l,3-dione, yellow solid.
1 H NMR (CDC13) δ:16.63(1H, s), 9.05(1H, d), 8.90(1H, m), 8.37(1H, d), 8.12(1H, d),
7.14(1H, dd), 2.86(2H, bs), 2.44(2H, bs), 2.09(2H, quintet).
From 6-methyl-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[6-methyl-
2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow
solid.
1H NMR (CDC13) δ:16.66(1H, s), 9.10QH, d), 8.01(1H, s), 7.98(1H, d), 2.80(2H, bs),
2.60(3H, s), 2.44(2H, bs), 2.07(2H, quintet).
From 7-methyl-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[7-methyl-
2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow
solid.
1H NMR (CDC13) δ:16.73(1H, s), 8.13(1H, d), 8.05(1H, s), 7.52(1H, d), 2.87(3H, s),
2.84(2H, t), 2.42(2H, broad t), 2.07(2H, quintet).
From 7-ethyl-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[7-ethyl-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow solid, lH NMR (CDC13) δ:16.74 (1H, s), 8.15 (1H, d), 8.06 (1H, d), 7.54 (1H, d), 3.15 (2H, q), 2.84 (2H, t), 2.42 (2H, t), 2.08 (2H, quintet), 1.46 (3H, t). Molecular ion: (MH)+ 365.
From 7-methoxymethyl-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[7-methoxymethyl-trifluoromethyl- [1,8] -naphthyridine-3-carbony] -cyclohexane-1,3-dione, yellow solid, lH NMR (CDC13) δ:16.70 (1H, s), 8.27 (1H, s), 7.88 (1H, d), 4.87 (s, 2H), 3.53, (3H, s), 2.85 (2H, t), 2.43 (2H, t), 2.08 (2H, quintet).
From 7-emyl-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[7-emyl-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow solid, 1H NMR (CDC13) δ: 8.02 (1H, s), 7.75 (1H, s), 3.20-3.14 (2H, m), 2.83 (2H,broads),2.43 (2H,broad s),2.07 (2H, quintet), 1.46(3H,t). Molecular ion: (MH)+ 383.
From 6-fluoro-7-methylemyl-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[6-fluoro-7-methylethyl-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow solid, lH NMR (CDC13) δ: 8.01 (1H, s), 7.75 (1H, d), 3.03(2H, double doublet), 2.80 (2H, broad s), 2.41 (2H, broad s), 2.42-2.33 (1H, m), 1.01 (6H, d). Molecular ion: (MH)+ 397.
From 7-cyclopropyl-6-fluoro-2-trifluoromethyl-[ 1,8]-naphthyridine-3-carboxylic acid, 2-[7-cyclopropyl-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow solid, lH NMR (CDC13) δ:7.97 (1H, s), 7.79 (1H, d), 2.86-2.37 (5H, m), 2.07 (2H, quintet), 1.59-1.57 (2H, m), 1.29-1.24 (2H, m). Molecular ion: (MH)+ 395
From6-fluoro-7-(2-methylpropyl)-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid,2-[6-fluoro-7-(2-methylpropyl)-2-trifluorome%l-[l,8]-naphmyridine-3-carbony]-cyclohexane-l,3-dione, yellow solid, lH NMR (CDCl3) δ: 8.01 (1H, s), 7.75
(1H, d), 3.03(2H, double doublet), 2.80 (2H, broad s), 2.41 (2H, broad s), 2.42-2.33 (1H, m), 1.01 (6H, d). Molecular ion: (MH)+ 411.
From 7-n.butyl-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[7-butyl-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow solid, lH NMR (CDC13) δ: 8.01 (1H, s), 7.74 (1H, d), 3.14 (2H, td), 2.78 (2H, broads), 2.47 (2H, broad s), 2.07 (2H, quintet), 1.87 (2H, quintet), 1.52-1.43 (2H, m), 0.98 (3H, t). Molecular ion: (MH)+ 410.
From 6-fluoro-7-[(E)(prop-l-enyl)]-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-(6-fluoro-7-[(E) (prop-l-enyl)]-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony)-cyclohexane-l,3-dione, pale orange solid, 1H NMR (CDC13) δ:16.67 (1H, s), 7.97 (1H, s), 7.75 (1H, d), 7.63-7.52 (1H, m), 6.92 (1H, d), 2.84 (2H, t), 2.42(2H, t), 2.09-2.07 (5H, m). Molecular ion: (MH)+ 395.
From 6-fluoro-7-[(E)(styryl)]-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-(6-fluoro-7-[(E)(styryl)]-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony)-cyclohexane-l,3-dione, yellow solid, Molecular ion: (MH)+ 457.
From 6-fluoro-7-[(4-methoxyphenyl)]-2-trifluoromethyl-[ 1,8]-naphthyridine-3-carboxylic acid, 2-[6-fluoro-7-[(4-methoxyphenyl)]-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow solid, 1H NMR (CDC13) δ: 8.28 (2H, d), 8.02 (1H, s), 7.86 (1H, d), 7.05 (2H, d), 3.92 (3H, s), 2.84 (2H, t), 2.42 (2H, t), 2.05 (2H, quintet). Molecular ion: (MH)+ 461.
From 6-fluoro-7-(thiophen-3-yl)-2-trifluoromediyl-[l,8]-naphdiyridine-3-carboxylic acid, 2-[6-fluoro-7-(thiophen-3-yl)-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow solid, 1H NMR (CDC13) δ:16.57 (1H, s), 8.45 (1H, broad s), 8.19 (1H, d), 8.02 (1H, d), 7.46 (1H, double doublet), 2.85 (2H, broad s), 2.43 (2H, broad s), 2.08 (2H, quintet). Molecular ion: (MH)+ 437.
From 6-fluoro-7-[(4-fluorophenyl)]-2-trifluoromethyl-[ 1,8]-naphthyridine-3-carboxylic acid, 2[6-fluoro-7-[(4-fluorophenyl)]-2-trifluoromethyl-[l,8]-
naphthyridine-3- carbony]-cyclohexane-1,3-dione, yellow solid, 1H NMR (CDC13) δ: 8.26-8.28(2H, m), 8.05 (1H, s), 7.92 (1H, d), 7.24 (2H, d), 2.85 (2H, broad s), 2.44 (2H, broad s), 2.05 (2H, quintet). Molecular ion: (MH)+ 449.
From 7-(l,l-difluoroethyl)-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[7-(l ,l-difluoroethyl)-6-fluoro-2-trifluoromeuiyl-[l,8]-naphthyridine-3- carbony]-cyclohexane-l,3-dione, yellow solid,1H NMR (CDC13) δ: 8.08 (1H, s), 7.95 (1H, d), 2.85 (2H, broad s), 2.42 (2H, broad s), 2.23 (3H, t), (2H, quintet). Molecular ion: (MH)+ 418.
From 6-fluoro-7-fluoromethyl-2-trifluoromethyl-[ 1,8] -naphthyridine-3 -carboxylic acid, 2-[6-fluoro-7-fluoromethyl-2-trifluoromethyl- [1,8]-naphthyridine-3- carbony] -cyclohexane-l,3-dione, yellow solid, 1H NMR (CDC13) δ: 8.08 (1H, s), 7.92 (1H, d), 5.82 (2H, d), 2.83 (2H, t), 2.42 (2H, t), 2.08 (2H, t). Molecular ion: (MH)+ 387.
From 6-fluoro-2-methoxymethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[6-fluoro-2-methoxymethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, brown solid. 1H NMR (CDC13) δ: 9.03 (1H, d), 7.93 (1H, s), 7.81 (1H, double doublet), 4.83 (2H, s), 3.25 (3H, s), 2.83 (2H, t), 2.44 (2H, t), 2.06 (2H, quintet). Molecular ion: (MH)+331.
From 5,7-dimethyl-6-fluoro-2-trifluoromethyl-[1,8]-naphthyridine-3-carboxylic acid, 2-[5,7-dimethyl-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow solid. 1H NMR (CDC13) δ:16.69(1H, s), 8.13 (1H, s), 7.82(1H, d), 2.85(2H, t), 2.81(3H, d), 2.59(3H, d), 2.42(2H, t), 2.08(2H, quintet).
From 6-fluoro-2-methoxymethyl-7-methyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[6-fluoro-2-methoxymethyl-7-methyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-1,3-dione, brown solid. lH NMR (CDC13) δ: 7.88 (1H, s), 7.69(1H, d), 4.81(2H, s), 3.23(3H, s), 2.79(3H, d), 2.61(4H, broad signal), 2.07(2H, quintet).
From 6-fluoro-2-(l,l-difluoro-2-methoxyethyl)-7-methyl-[l,8]-naphthyridine-3-
carboxylic acid,2-[6-fluoro-2-(l,l-difluoro-2-methoxyethyl)-[l,8]-naphthyridine-3-
carbony]-cyclohexane-l,3-dione, colourless solid, Molecular ion: (MH)+ 395,
1H NMR (CDCl3) δ:16.7(1H, s), 7.94(1H, s), 7.72-7.74(lH, d), 4.28-4.38(2H, broad
triplet), 3.50(3H, s), 2.84(3H, d), 2.80-2.84(2H, t), 2.38-2.42(2H, t), 2.04-2.10(2H, m).
From 2-methyl-7-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[2-methyl-7-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, brown solid. 1H NMR (CDC13) δ:17.25(1H, s), 8.35 (1H, d), 7.93(1H, s), 7.82(1H, d), 2.86(2H, d), 2.72(3H, s), 2.47(2H, t), 2.10(2H, quintet).
From 2-ethyl-7-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[2-ethyl-7-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow solid. lH NMR (CDC13) δ: 17.26 (1H, s), 8.34 (1H, d), 7.90 (1H, s), 7.82 (1H, d), 2.98 (2H, q), 2.88 (2H, t), 2.46 (1H, t), 2.12 (2H, qi), 1.40 (3H, t)
From 2-(memanesulfonyl-N-methylaminomethyl)-7-trifluoromethyl-[l,8]-naphmyridine-3-carboxylic acid, 2-[{methanesulfonyl-N-methylaminomethyl}-7-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, 1H NMR (CD3OD ) δ: 8.75 (1H, d), 8.35(1H, s), 8.05(1H, d), 4.65(2H, s), 2.95(3H, s). 2.65QH, s), 2.30-3.00(4H, broad signal), 2.10(2H, quintet).
From 6-fluoro-7-(2,2,2-trifluoroemylamino)-2-trifluoromethyl-[ 1,8]-naphtiiyridine-3-carboxylic acid, 2-[6-rluoro-7-(2,2,2-trifluoroethylamino)-2-trifluoromethyl-[ 1,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione. 1H NMR (CDC13) δ:16.78(1H, s), 7.86(1H, s), 7.58(1H, d), 5.69(1H, broad s), 4.59-4.50(2H, m), 2.83(2H, t), 2.42(2H, t), 2.07(2H, quintet).
From 7-(3,3-difluoroazetidm-l-yl)-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[7-(3,3-difluoroazetidin-l-yl)-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione. 1H NMR (CDC13) δ:16.80(1H, s), 7.84(1H, s), 7.55(1H, d), 4.79(4H, m), 2.83(2H, t), 2.42(2H, t), 2.07(2H, quintet).
From 6-fluoro-7-(3-methoxyazetidin-l-yl)-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[6-fluoro-7-(3-methoxyazetidin-l-yl)- 2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione. 1H NMR (CDC13) δ:16.89(1H, s), 7.75(1H, s), 7.41(1H, d), 4.66-4.62(2H, m), 4.42-4.34(3H, m), 3.37(3H, s), 2.81(2H, t), 2.42(2H, t), 2.06(2H, quintet).
From 7-(cyclopropylamino)-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[7-(cyclopropylamino)-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione. 1H NMR (CDCI3) δ:16.88(1H, s), 7.79(1H, s), 7.42(1H, d), 5.62(1H, s), 5.27-5.23(lH, m), 2.82(2H, t), 2.42(2H, t), 2.06(2H, quintet), 1.03-0.98(2H, m), 0.69-0.65(2H, m).
From 6-fluoro-7-methylamino-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[6-fluoro-7-methylamino-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione. lH NMR (CDC13) δ: 7.80 (1H, s), 7.46 (1H, d), 6.78 (1H, bs), 3.22 (3H, d), 2.75 (4H, bs), 2.05 (2H, quintet).
From 7-(dimethylamino)-6-fluoro-2-trifluoromethyl-[ 1,8]-naphthyridine-3-carboxylic acid, 2-[7-(dimethylamino)-6-fluoro-2-trifluoromethyl-[l ,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione. lH NMR (CDC13) δ: 7.76(1H, s), 7.46(1H, d), 3.40(6H, d), 2.86(2H, broad signal), 2.42(2H, broad signal), 2.06(2H, quintet).
From7-(diethylamino)-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[7-(diethylamino)-6-fluoro-2-trifluoromethyl-[ 1,8]-naphthyridine-3- carbony]-cyclohexane-l,3-dione. 1H NMR (CDC13) δ:16.90(1H, s), 7.72(1H, s), 7.44(1H, d), 3.78(4H, q), 2.80(2H, m), 2.40(2H, m), 2.05(2H, m), 1.30(6H, t).
From 6-fluoro-7-(N-methylethylamino)-2-trifluoromethyl-[l,8]-naphthyridine carboxylic acid, 2-[6-fluoro-7-(N-methylethylamino)-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione. lH NMR (CDC13) δ: 7.74 (1H, s), 7.46 (1H, d), 3.80 (2H, q) 3.37 (3H, d), 2.60 (4H, bs), 2.04 (2H, quintet), 1.29 (3H, t).
rom 6-fluoro-7-(2-methoxyethylamino)-2-trifluoromethyl-[ 1,8]-naphthyridine-3-carboxylic acid, 2-[6-fluoro-7-(2-methoxyethylamino)-2-trifluoromethyl-[l,8]-naphthyridine-3- carbony]-cyclohexane-l,3-dione, yellow solid, 1H NMR (CDCI3) δ: 16.88 (1H, s), 7.76(1H, s), 7.46(1H, d), 5.90 (1H, bs), 3.98 (2H, m), 3.68 (2H, t), 3.42 (3H, s), 2.80 (2H, t), 2.42(2H, broad signal), 2.06(2H, quintet).
From 6-fluoro-7-(2-methoxyethylmethylamino)-2-trifluorometb.yl-[l,83-naphthyridine-3-carboxylic acid, 2-[6-fluoro-7-(2-methoxyethylmethylaniino)-2-trifluoromediyl-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione. lHNMR (CDC13) δ:16.97(1H, s), 7.76(1H, s), 7.49(1H, d), 3.98(2H, m), 3.69(2H, t), 3.45(3H, d), 3.35(3H, d), 2.81(2H, t), 2.42(2H, t), 2.06(2H, quintet).
From6-fluoto-7-(morpholin-4-yl)-2-trifluorome1hyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[6-fluoro-7-(morpholin-4-yl)-2-trifluoromethyl-[l,8]-naphthyridine-3-carbonyl-cyclohexane-1,3-dione.1H NMR (CDC13) δ: 7.82(1H, s), 7.58(1H, d), 3.98(4H, m), 3.86(4H,m), 3.45(3H, d), 2.81(2H, t), 2.42(2H, t), 2.06(2H, quintet).
From6-fluoro-7-propargylamino)-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid, 2-[6-fluoro-7-propargylamino)-2-trifluoromethyl-[1,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione lH NMR (CDC13) δ:7.82(1H, s), 7.51(lH,d), 5.60 (1H, bs), 4.60 (1H, m), 2.82 (2H, t), 2.42 (2H, t), 2.34 (1H, t), 2.08 (2H, quintet).
From 6-fluoro-7-methyl-2[(2,2,2-trifluoroethoxy)difluoromethyl]-[ 1,8]-naphthyridine-3-carboxylic acid, 2-[6-fluoro-7-methyl-2[(2,2,2-trMuoroethoxy)difluoromethyl]-[l,8]-naphthyridine-3-carbony]-cyclohexane-l,3-dione, yellow solid. !HNMR {CDCl3) δ:7.95(1H, s), 7.72(1H, d), 4.38(2H, q), 2.83(3H, d), 2.81(2H, broad s), 2.39(2H, broad s), 2.04(2H, quintet).
Example 2
Preparation of 2-(7-ethoxy-2-trifluoromethyl-ri.81-naphthyridine-3-carbonyl)-
cyclohexane-l,3-dione
Stage 1
Preparation of ethyl 8-oxy-2-trifluoromethyl-[1,8]-naphthyridine-3-carboxylate
To a stirred solution of ethyl 2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate (74g) in dichloromethane (1000ml) at 10°C was added urea hydrogen peroxide (130g, 30% active oxygen) followed by trifluoroacetic anhydride (63ml) in portions allowing the mixture to reflux. The mixture was stirred for 6 hours during which time the mixture cooled to ambient temperature. It was then heated to reflux for 0.5 hours, cooled to ambient temperature then washed with aqueous sodium thiosulfate (20ml, 0.1M), then aqueous sodium hydrogen carbonate (2x15ml) and brine (20ml). The organic phase was separated, dried over magnesium sulphate, filtered then evaporated under reduced pressure to give a solid. The solid was purified by chromatography (silica, ethyl acetate then methanol) to give the required product as a pale yellow solid, 41g. 1H NMR (CDC13) δ: 8.83(1H, dd), 8.81(1H, s), 7.79(1H, dd), 7.56(1H, dd), 4.51(2H, q), 1.45(3H, t).
Stage 2
Preparation of ethyl 7-chloro-2-trifluoromethyl-[1,8]-naphthyridine-3-carboxylate To a stirred solution of ethyl 8-oxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate (41.0g) in dry dichloromethane (700ml) containing triethylamine (26ml) at 10°C was added dropwise phosphorus oxychloride (17.0ml). The mixture was allowed to warm to ambient temperature and stirred for 1 hour then heated to reflux for a further 4 hours. The mixture was cooled to ambient temperature, poured into water then taken to pH 7 with sodium hydrogen carbonate. The organic phase was separated, washed with brine, dried over magnesium sulphate, filtered then evaporated under reduced pressure. The residual material was purified by chromatography (silica, hexane / ethyl acetate / 3:2 by volume) to give a pink solid, 34g, that contained a mixture of the ethyl 7-chloro-2-trfluoromethyl-[1,8]-naphmyridine-3-carboxvlate (4 parts) and ethyl 5-chloro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate (1 part). The material was used in the next stage without further purification. A sample was purified by chromatography (silica, hexane/ethyl acetate, 4:1 by volume) to give a pure sample of ethyl 7-chloro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate as a pale pink solid.
1H NMR (CDC13) δ: 8.76(1H, s), 8.30(1H, d), 7.70(1H, d), 4.50(2H, q), 1.45(3H, t). Molecular ion: (MH)+ 305.
Stage 3
Preparation of ethyl 7-ethoxy-2-trifluoromethyl-[1,8]-naphthyridine-3-carboxylate To a stirred solution of ethyl 7-chloro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate (4.65g) in ethanol (15ml) at ambient temperature was added in portions sodium ethoxide (1.14g). The mixture was stirred for 1 hour then heated to reflux for a further 16 hours. The mixture was cooled to ambient temperature, diluted with water (20ml) and extracted with ethyl acetate (30ml). The organic fraction was separated, washed with brine, dried over magnesium sulphate, filtered and evaporated under reduced pressure. The residual solid was purified by chromatography (silica, hexane/ethyl acetate) to give the required product, 3.15g. lH NMR (CDC13) δ: 8.60(1H, s), 8.11(1H, d), 7.15(1H, d), 4.70(2H, q), 4.47(2H, q), 1.48(3H, t), 1.43(3H, t).
Stage 4
Preparation of 7-ethoxy-2-trifluoromethyl-[1,8]-naphthyridine-3-carboxylic acid Ethyl 7-ethoxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate (3.10g) in ethanol (20ml) was added aqueous 2M sodium hydroxide (10ml) at ambient temperature. The mixture was stirred for 3 hours, acidified to pH 1 with aqueous 2M hydrochloric acid and extracted three times with ethyl acetate. The extracts were combined, washed with brine, dried over magnesium sulphate, filtered and evaporated under reduced pressure to give the required product, 2.86g. lH NMR (d6-DMSO) δ: 8.98(1H, s), 8.54(1H, d), 7.36(1H, d), 4.58(2H, q), 1.43(3H, t). Molecular ion: (MH)+ 287.
Stage 5
In a similar procedure to Example 1, Stage 3, cyclohexane-l,3-dione was reacted with
7-ethoxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid to give the required
product as a yellow solid. lH NMR (CDC13) δ:16.76(1H, s), 8.01(1H, d), 7.96(1H, s),
7.09(1H, d), 4.69(2H, q), 2.34-2.94(4H, bs), 2.07(2H, quintet), 1.46(3H, t). Molecular
ion:(MH)+371.
In a similar procedure to Example 1, Stage 3, the following compounds were prepared from the corresponding 7-alkoxynaphthyridine-3-carboxylic acids and cyclohexane-1,3-dione or bicyclo[3.2.1]octane-2,4-dione:
2-(7-methoxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carbonyl)-cyclohexane-l,3-dione, yellow solid. lH NMR (CDC13) δ:16.69(1H, s), 8.02(1H, d), 7.98(1H, s), 7.11(1H, d), 4.21 (3H, s), 2.82(2H, broad s), 2.42(2H, broad s), 2.06(2H, quintet). 3-(7-medioxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony)-bicyclo[3.2.1]octane-2,4-dione, colourless solid. lH NMR (CDC13) δ:16.79(1H, s), 8.03(1H, d), 8.00(1H, s), 7.12(1H, d), 3.18 (3H, bs), 2.88(1H, broad s), 2.23-2.02(4H, m), 1.78-1.72(2H, m). 2-(7-isopropoxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carbonyl)-cyclohexane-l,3-dione, colourless solid. lH NMR (CDC13) δ:16.83(1H, s), 7.99(1H, d), 7.95(1H, s), 7.04(1H, d), 5.85 (1H, septet), 2.83(2H, t), 2.43(2H, t), 2.07(2H, quintet). 2-(7-Allyloxy-2-triflu6romethyl-[l,8]-naphthyridine-3-carbonyl)-cyclohexane-l,3-dione, yellow solid. lH NMR (CDC13) δ:16.85(1H, s), 8.09(1H, d), 8.03(1H, s), 7.20(1H, d), 6.27-6.16 (1H, m), 5.55(1H, m), 5.38(1H, m), 5.20(2H, m), 2.88(2H, broad s), 2.47(2H, broad s), 2.12(2H, quintet).
2-(2-Methoxyethoxy)-2-liifluoromethyl-[l,8]-naphmyridine-3-carbonyl)-cyclohexane-l,3-dione, yellow solid. lH NMR (CDC13) δ:16.79(1H, s), 8.04(1H, d), 7.98(1H, s), 7.20(2H, d), 4.82-4.79 (2H, m), 3.84-3.82(2H, m), 3.46(3H, s), 2.83(2H, t), 2.42(3H, t), 2.07(2H, quintet).
2-(7-(2,2,2-Trifluoroethoxy)-2-trifluorometiiyl-[l,8]-naphthyridine-3-carbonyl)-cyclohexane-l,3-dione, yellow solid. lH NMR (CDC13) δ:16.70(1H, s), 8.15(1H, d), 8.04(1H, s), 7.26(2H, d), 5.06 (2H, q), 2.84(2H, broad s), 2.43(2H, broad s), 2.33(2H, t), 2.08(2H, quintet).
In a similar procedure to Example 1, Stage 3,7-phenoxy-2-trifluoromethylnaphthyridine-3-carboxylic acid was reacted with cyclohexane-1,3-dione to give 2-(7-phenoxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carbonyl)-cyclohexane-l,3-dione. 1H NMR (CDC13) δ:16.75(1H, s), 8.18(1H, d), 8.02(1H, s), 7.45(2H, m), 7.35(1H, d), 7-27(3H, m), 2.83(2H, t), 2.33(2H, t), 2.06(2H, quintet). Molecular ion: (MH)+ 429.
In a similar procedure to Example 1, Stage 3 the following compounds were prepared from 7-ethoxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid and the corresponding ketones:
6-(7-ethoxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carbonyl)-2,2,4,4,-tetramethylcyclohexane-l,3,5-trione, yellow solid, lH NMR (CDC13) δ:17.32(1H, s), 8.06(1H, s), 8.05(1H, d), 7.13(1H, d), 4.70(2H, q), 1.58(6H, s), 1.48(3H, t), 1.30(6H, s),1.32(12H, s).
3-(7-ethoxy-2-trifluoromethyl-[l,8]-naphmyridine-3-carbonyl)-bicyclo[3.2.1]octane-2,4-dione, pale yellow solid. lH NMR (CDC13) δ:16.79(1H, s), 8.02(1H, d), 7.98(1H, s), 7.09(1H, d), 4.69(2H, q), 3.17-2.91(2H, m), 2.23-2.02(4H, m), 1.77-1.72(2H, m), 1.47(3H, t).
2-emyl-4-(7-ethoxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony)-2,4-dihydropyrazol-3-one, pale yellow solid. 1H NMR (CDCl3) δ: 8.31 (1H, s), 8.09QH, d), 7.35(1H, s), 7.17(1H, d), 4.71(2H, q), 4.10(2H, q), 1.49(6H, dt).
Example 3
Preparation of 2-ethyl-4-(7-hydroxy-2-trifluoromethyl-[1,8]-naphthyridine-3-carbony)- 2,4-dihvdropyrazol-3-one
A suspension of 2-ethyl-4-(7-ethoxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony)- 2,4-dihydropyrazol-3-one (0.35g) in ethanol (2ml) and aqueous 2M hydrochloric acid (3ml) was heated with stirring to 130°C in a sealed vessel in a microwave oven for 15 minutes where upon a solution was obtained. This was diluted with water (20ml), extracted with ethyl acetate and the organic fraction separated, dried over magnesium sulphate, filtered then evaporated under reduced pressure to give the required product as a pale yellow solid, 0.29g. 1H NMR {d6-DMSO) δ:12.67(1H, s), 8.43 (1H, s), 8.04(1H, d), 7.53(1H, s), 6.77(1H, dd), 3.91(2H, q), 1.26(3H, t). Molecular ion: (MH)+ 353.
The following compounds were prepared in a similar procedure to Example 3 from the corresponding 7-ethoxynaphthyridines:
2-(7-hydroxy-2-trifluoromethyl-[l,8]-naphihyridine-3-carbony)-cyclohexane-l,3-dione, colourless solid. 1H NMR (CDC13) δ:15.87(1H, bs), 12.68(1H, bs), 8.25 (1H, s), 7.96(2H, d), 6.77(2H, d), 3.34(2H, bs), 2.59(2H, bs), 1.95(2H, quintet). 3-(7-hydroxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony)-bicyclo[3.2.1]octane-2,4-dione, colourless solid. lH NMR (4-DMSO) δ:12.66(1H, s), 8.23 (1H, s), 7.98(1H, d), 6.65(1H, dd), 3.34-1.67(8H, m).
6-(7-hydroxy-2-trifluorome1hyl-[l,8]-naphthyridine-3-carbony)-2,2,4,4,-tetramethylcyclohexane-l,3,5-trione, colourless solid. lH NMR (d6-DMSO) δ: 12.67(1H, s), 8.23 (1H, s), 7.98(1H, d), 6.75(1H, d), 1.32(12H, s).
Example 4
Preparation of 6-fluoro-2-trifluoromethyl[1,8]naphthyridine-3-carbonyl)-
cyclohexane-1,3-dione
Stage 1
Preparation of 2-amino-5-bromopyridine-3-carboxaldehyde
To a stirred solution of 2-aminopyridine -3-carboxaldehyde (20g) in acetoniltrile (300
ml) was added N-bromosuccinimide (30.0g) and the mixture was heated to reflux for
1.5 hours. The mixture was cooled to ambient temperature and the required product
that precipitated from solution as a golden brown solid was filtered and sucked to
dryness, 22.5g.
lH NMR (CDC13) δ: 9.83(1H, s), 8.31(1H, d), 8.24(1H, d), 7.70(2H, s).
Stage 2
Preparation of ethyl 6-bromo-2-trifluoromethyl-[1,8]-naphthvridine-3-carboxylate
A mixture of 2-amino-5-bromopyridine-3-carboxaldehyde (15.0g) and ethyl 4,4,4-
trifluoroacetoacetate (10.8ml) in ethanol (100ml) containing piperidine (7.4ml) was
stirred and heated to reflux for 3 hours. The reaction mixture was cooled in an ice bath
and the required product that precipitated as a yellow solid, 17.5g, was filtered from
solution, washed with a little cold ethanol and sucked to dryness.
1H NMR (CDC13) δ: 9.30(1H, d, 8.67(1H, s), 8.52(1H, d), 4.50(2H, q), 1.45(3H, t).
Stage 3
Preparation of ethyl 6-aniino-2-trifluoromethyl-[1,8]-naphthyridine-3-carboxylate
A mixture of ethyl 6-bromo-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate
(3.0g), cesium carbonate (4.19g), palladium acetate (0.096g), benzophenone imine
(1.7ml) and 4,5-bis-diphenylphosphoranyl-9,9-dimethyl-9H-xanthene (0.372g) in dioxane (5ml) was heated with stirring to 150°C in a sealed vessel in a microwave oven for 15 minutes then cooled to ambient temperature. Another batch of these reagents was processed in the same manner and the combined solutions combined and evaporated under reduced pressure to remove most of the solvent. The residue was treated with concentrated hydrochloric acid (15ml), washed with ethyl acetate and the aqueous fraction separated. The organic fraction was further extracted with dilute hydrochloric acid (3x20ml) and the aqueous acidic fractions combined, taken to pH 7 with aqueous sodium hydroxide then extracted with ethyl acetate (3x30ml). The organic fractions were combined, washed with brine (2x20ml), dried over magnesium sulphate, filtered and evaporated under reduced pressure to give an orange solid. The solid was purified by chromatography (silica, hexane /ethyl acetate) to give the required product as a yellow solid, 2.3g. lH NMR (CDC13) δ: 8.85(1H, d), 8.44(1H, s), 7.26(1H, d), 4.47(2H, q), 1.43(3H, t).
Stage 4
Preparation of ethyl 6-fluorc^2-trifluoromethvl-ri.81-naphthyridine-3-carboxylate To a stirred suspension of ethyl 6-amino-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate (1.40g) in tetrafluoroboric acid (1.3ml, 48%) cooled in an icebath was added dropwise a solution of sodium nitrite (0.70g) in water (0.9ml). On complete addition, the mixture was stirred for a further 1 hour and the fine precipitate that had formed was filtered from solution, sucked to dryness then washed with hexane and dried under vacuum. The dry solid was heated until the diazonium tetrafluoroborate salt had fully decomposed producing a dark brown gum of the required fluoride. The gum was dissolved in ethyl acetate, washed with aqueous sodium hydrogen carbonate (2x30ml), dried over magnesium sulphate, filtered and evaporated under reduced pressure. The residue was purified by chromatography (silica, hexane/ diethyl ether) to provide the required product as a pale yellow solid. 0.80g. lH NMR (CDC13) δ: 9.24(1H, d), 8.77(1H, s), 8.00(1H, d), 4.54(2H, q), 1.49(3H, t).
Stage 5
Preparation of 6-fluoro-2-trifluoromethyl-[1,8]-naphthyridine-3-carboxylic acid
To a stirred suspension of ethyl 6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate (0.73g) in a mixture of ethanol (30ml) and water (10ml) was added lithium hydroxide hydrate (0.152g) at ambient temperature. The mixture was stirred for 1 hour, diluted with ethyl acetate (50ml), the organic fraction was separated and extracted with aqueous 2M sodium hydroxide (2x10ml). The aqueous fractions were combined, taken to pH 1 with aqueous 2M hydrochloric acid and extracted into ethyl acetate (4x20ml). The extracts were combined, dried over magnesium sulphate, filtered and evaporated under reduced pressure to give the required product as a pale yellow solid, 0.52g. lH NMR (CDC13) δ:9.39(1H, dd), 9.13(1H, s), 8.60(1H, dd).
Stage 6
To a stirred suspension of 6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid (0.390g) and cyclohexan-l,3-dione (0.190g) in dry acetonitrile (10ml) at ambient temperature was added N,N-dicyclohexylcarbodiimide (0.344g). The reaction mixture was stirred for 4 hours, filtered and the filtrate treated with triethylamine (0.290ml) and acetone cyanohydrin (0.040ml). The mixture was stirred for 16 hours, evaporated under reduced pressure and the residue purified by chromatography (silica, toluene/dioxane/ethanol/triemylamine/water, 20:8:4:4:1 by volume) to give the required product as the triethylamino salt. The salt was dissolved in ethyl acetate (30ml), washed with aqueous 2M hydrochloric acid (2x 5ml), water (3x10ml), dried over magnesium sulfate then evaporated under reduced pressure to give the required product as a pale brown solid, 0.130g.
1H NMR (CDC13) δ:16.56(1H, s), 9.15(1H, d), 8.06(1H, s), 7.86(1H, dd), 2.86(2H, t), 2.43(2H, t), 2.09(2H, quintet).
Example 5
Preparation of 2-(6-fluoro-7-hydroxy-2-trifluoromethyl-[1,8]-naphthyridine-3-
carbonyl)- cyclohexane-l,3-dione
Stage 1
Preparation of ethyl 8-oxy-6-fluoro-2-trifluoromethyl-[1,8]-naphthyridine-3-
carboxylate
To a stirred solution of ethyl 6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate (4.2g) in dichloromethane (60ml) containing urea hydrogen peroxide (9.2g, 30% peroxide) at ambient temperature was added in portions trifluoroacetic anhydride (4.2ml). During the addition the mixture started to reflux then gradually cooled to ambient temperature again. The mixture was stirred for 3 hours, washed with aqueous 0.1M sodium dithionite (20ml), brine (20ml) then dried over magnesium sulphate, filtered and evaporated under reduced pressure to give a solid. The solid was purified by chromatography (silica, hexane/ethyl acetate) to give the required product as a solid, 2.5g. 1H NMR (CDCl3) δ: 8.78(1H, m), 8.76 (1H, s), 7.49(1H, m), 4.5.1(2H, q), 1.45(3H, t).
In a similar procedure, ethyl 6-fluoro-5-methyl-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate was oxidised to ethyl 6-fluoro-5-methyl-8-oxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate, yellow solid, lH NMR (CDC13) δ: 8.92(1H, s), 8.88 (1H, d), 4.54(2H, q), 2.68(3H, d), 1.45(3H, t). Molecular ion: (MH)+ 319
Stage 2
Preparation of ethyl 7-chloro-6-fluoro-2-trifluoromethyl-[1,8]-naphthvridine-3-carboxylate and ethyl 5-chloro-6-fluoro-2-trifluoromethyl-[1,8]-naphthvridine-3-carboxylate
To a stirred solution of ethyl 8-oxy-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate (2.41g) in dry dichloromethane (100ml) containing dry triethylamine (1.4ml) cooled tol0°C was added dropwise at ambient temperature phosphoryl chloride (0.930ml). On complete addition, the mixture was stirred for 30 minutes at ambient temperature then heated to reflux for 4 hours. The mixture was cooled to ambient temperature, washed with saturated aqueous sodium hydrogen carbonate then brine and dried over magnesium sulphate, filtered and evaporated under reduced pressure. The residue was purified by chromatography (silica, hexane / ethyl acetate) to give ethyl 7-chloro-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate, 0.45g, 1H NMR (CDC13) δ: 8.73(1H, s), 8.02 (1H, d), 4.49(2H, q), 1.45(3H, t) and emyl 5-chloro-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate, 0.300g. lH NMR (CDC13) δ: 8.76(1H, s), 8.02 (1H, d), 4.50(2H, q), 1.44(3H, t).
In a similar procedure, ethyl 6-fluoro-5-methyl-8-oxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate was reacted to give ethyl 7-chloro-6-fluoro-5-methyl-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylate, yellow solid, lH NMR (CDCI3) δ: 8.82 (1H, s), 4.52(2H, q), 2.76(3H, d), 1.46(3H, t). Molecular ion: (MH)+ 337
Stage 3
Preparation of 7-ethoxy-6-fluoro-2-trifluoromethyl-[1,8]-naphthyridine-3-carboxvlic
acid
A solution of ethyl 7-chloro-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-
carboxylate (0.45g) in ethanol (4ml) containing sodium ethoxide (o.l43g) was sealed
in a tube and heated with stirring in a microwave oven at 100°C for 10 minutes then
allowed to cool to ambient temperature. The solution was diluted with ethanol (2ml)
and aqueous 2M sodium hydroxide (2ml) was added then the mixture was stirred for 2
hours at ambient temperature. The solution was acidified to pHl with 2M
hydrochloric acid, extracted with ethyl acetate (2x10ml), dried over magnesium
sulphate, filtered then evaporated under reduced pressure to give the required product
as a pale yellow solid, 0.40g. lH NMR (d6-DMSO) δ: 8.95(1H, s), 8.45 (1H, d),
4.66(2H, q), 1.46(3H, t).
Stage 4
In a similar procedure to Example 1, Stage 3, cyclohexane-1.3-dione and 6-fluoro-7-
emoxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid were reacted to give
6-fluoro-7-ethoxy-2-trifluoromethyl-[ 1,8]-naphthyridine-3-carbonyl)- cyclohexane-
1,3-dione as a pale yellow solid. 1H NMR (CDCl3) δ:16.72(1H, s), 7.93(1H, s), 7.67
(1H, d), 4.78(2H, q), 2.83(2H, t), 2.42(3H, t), 2.07(2H, quintet), 1.53(3H, t).
Stage5
A suspension of 2(6-fluoro-7-ethoxy-2-trifluoromethyl-[l ,8]-naphthyridine-3-carbonyl)-cyclohexane-l,3-dione (0.12g) in aqueous 2M hydrochloric acid (3ml) and ethanol (2ml) was heated with stirring in a sealed tube in a microwave oven at 130°C for 15 minutes. The mixture was cooled to ambient temperature, filtered from solution, washed with water, sucked to dryness then washed with hexane to give the required product as a colourless solid, 0.082g.
lH NMR (CDCl3) δ:16.56(1H, bs), 13.04(1H, bs), 8.18 (1H, s), 7.84(1H, d), 3.06(4H, bs),2.63(2H,bs).
Example 6
Preparation of 2-(7-methylmercapto-2-trifluoromethyl[1 ,8]-naphthyridine-3-
carbonyl)- cyclohexane-l,3-dione
Stage 1
Preparation of ethyl 7-methylmercapto-2-trifluoromethyl-[1,8]-naphthyridine-3-
carboxylate
A solution of ethyl 7-chloro-6-fluoro-2-trifluoromethyl-[l,8]-naphthyridine-3-
carboxylate (l.0g) in acetonitrile (3ml) containing sodium thiomethoxide 0.65g) was
sealed in a tube and heated with stirring in a microwave oven at 130°C for 10 minutes
then allowed to cool to ambient temperature. The solution was diluted with ethyl
acetate (20ml), washed with brine (10ml), dried over magnesium sulphate, filtered
then evaporated under reduced pressure. The residue was purified by chromatography
(silica, hexane/ ethyl acetate, 4:1 by volume) to give the required product as a
colourless solid, 0.49g.
lH NMR (CDC13) δ: 8.62(1H, s), 7.98 (1H, d), 7.47(1H, d), 4.47(2H, q), 2.82(3H,
s),1.44(3H, t).
Stage 2
Preparation of 7-methylmercpto-2-trifluoromethyl-fl,81-naphthyridine-3-carboxylic
acid
To a stirred solution of ethyl 7-methylmercapto-2-trifluoromethyl-[l,8]-
naphthyridine-3-carboxylate (0.46g) in ethanol (7.5ml) containing water (2.5ml) was
added sodium hydroxide (0.12g) at ambient temperature. The mixture was stirred for
3 hours, acidified to pH 1 with 2M hydrochloric acid and extracted with ethyl acetate.
The organic fraction was separated, washed with brine, dried over magnesium sulfate,
filtered and evaporated under reduced pressure to give the required product, 0.38g.
1H NMR (d6,-DMSO) δ: 9.02(1H, s), 8.44 (1H, d), 7.76(1H, d), 2.71(3H, s).
Stage 3
In a similar procedure to Example 1, Stage 3, cyclohexan-l,3-dione was reacted with 7-methylmercapto-2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid to give 2-(7-methymercapto-2-trifluoromethyl-[13]-naphthyridine-3-carbonyl)-cyclohexane-1,3-dione as a yellow solid. 1H NMR (CDC13) δ:16.75(1H, s), 7.97(1H, s), 7.89(1H, d), 7.42(1H, d), 2.83(2H, t), 2.81(3H, s), 2.42(2H, t), 2.07(2H, quintet).
Example 7
Preparation of 2-(8-oxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony,)-
cyclohexane-1,3 -dione
To a stirred solution of 2-(2-trifluoromethyl-[l,8]-naphthyridine-3-carbony)-
cyclohexane-l,3-dione (0.500g) in dry dichloromethane (10ml) containing urea
hydrogen peroxide (0.078g, 30% peroxide) was added trifluoroacetic anhydride
(0.115ml). The mixture was stirred at ambient temperature for 20 hours, washed with
water (20ml) and evaporated under reduced pressure. The residue was purified by
chromatography (silica, toluene:dioxane,emanol:triemylamine:water, ratio by volume
20:8:4:4:1 increasing the ethanol content of the eluent until the desired product was
eluted) to give the triethylamine salt of the required product. The salt was dissolved
in dichloromethane (15ml) and acidified with aqueous 2M hydrochloric acid (5ml).
The organic fraction was separated, washed with water (10ml), dried over magnesium
sulfate then evaporated under reduced pressure to give the required product as an
orange solid, 0.17g.
lH NMR (CDC13) δ: 16.42(1H, s), 8.81(1H, dd), 8.16(1H, s), 7.69(1H, dd), 7.49(1H,
dd), 2.86(2H, t), 2.43(2H, t), 2.09(2H, quintet). Molecular ion: (MH)+ 337.
Example 8
Preparation of 2-(7-(but-2-ynyloxy)-2-trifluoromethyl-[1,8]-naphthyridine-3-
carbony)- cyclohexane-l,3-dione
A mixture of 2-(7-hydroxy-2-trifIuoromethyl-[l,8]-naphthyridine-3-carbony)-cyclohexane-l,3-dione (0.l00g) in chloroform (10ml) containing but-2-ynyl bromide (0.051ml) and silver carbonate (0.155g) were stirred and heated to reflux for 17 hours. The reaction was cooled to ambient temperature, diluted with ethyl acetate (20ml) then washed wim water (2x10ml), dried over magnesium sulfate, filtered and
evaporated under reduced pressure to give a gum. The gum was purified by chromatography (silica, hexane/ ethyl acetate) to give 3-(but-2-ynyloxy)-2-(7-[but-2-ynyloxy]-[l,8]-naphthyridin-3-carbonyl)-cyclohex-2-enone (0.050g). This was dissolved in ethanol containing 2M aqueous hydrochloric acid and stirred at ambient temperature for 10 minutes then diluted with ethyl acetate (15ml), washed with water (2x10ml), dried over magnesium sulfate, filtered and evaporated under reduced pressure to give the required product, 0.026g. lH NMR (CDC13) δ:16.70(1H, s), 7.99(1H, d), 7.92(1H, s), 7.11(1H, d), 5.18(2H, q), 2.76(2H, t), 2.35(3H, t), 2.00(2H, quintet), 1.85(3H, t). Molecular ion: (MH)+ 405.
Example 9
Preparation of 2-(2-trifluoromethyl-[1,8]-naphthyridine-3-carbony)-l,3-dicyclopropylpropan-l,3-dione
A mixture of l-cyclopropyl-3-(2-trifluoromethyl-[l,8]-naphthyridin-3-yl)- propane-1,3-dione (0.446g) and magnesium ethoxide (0.196g) was suspended in dry tetrahydrofuran (8ml) under an atmosphere of nitrogen and heated to reflux for 3 hours with stirring then cooled to ambient temperature. To the mixture was added cyclopropanecarbonyl chloride (0.13ml) then the reaction mixture was stirred at ambient temperature for a further 18 hours. Additional cyclopropanecarbonyl chloride (0.15ml) was added and the mixture heated to reflux with stirring for 2 hours, cooled to ambient temperature then stored for 2 days. The solvent was evaporated under reduced pressure and the residue acidified with aqueous 2M hydrochloric acid then extracted twice with ethyl acetate. The extracts were combined, washed with water and brine then dried over magnesium sulfate, filtered and evaporated under reduced pressure. The residue was re-dissolved in ethyl acetate, extracted three times with aqueous sodium hydrogen carbonate and the aqueous fractions were combined, washed with ethyl acetate then the aqueous fraction was acidified with aqueous 2M hydrochloric acid. The aqueous, acidic fraction was extracted three times with ethyl acetate, the extracts combined, dried over magnesium sulfate, filtered and evaporated under reduced pressure to give the required product as a brown gum, 0.168g. [H NMR {CDCI3) indicated that the material exists as a tautomeric mixture (ca. 1:1) of geometric enol isomers 8:18.60(1H, s),17.35(lH, s), 9.32(2H broad s), 8.61(1H, s),
8.39(1H, dd), 8.29(2H, m), 7.72(2H, m), 2.30(1H, m), 1.92(2H, m), 1.62(1H, m), 1.45(2H, m), 1.22(4H, m), 1.06(2H, m), 0.94(2H, m), 0.82(4H, m), 0.58(2H, bs).
Example 10
Preparation of 2-(2-trifluoromethyl-[1,8]-naphthyridine-3-carbony)-3-cyclopropyl-3-
oxopropionitrile
Stage 1
To a stirred suspension of 2-trifluoromethyl-[l,8]-naphthyridine-3-carboxylic acid
(2.0g) in dry dichloromethane (40ml) at ambient temperatureunder an atmosphere of
nitrogen was added N,N-dimethylformamide (0.05ml, catalyst) followed by oxalyl
chloride (1.3ml). The mixture was heated to reflux with stirring for 3 hours, cooled to
ambient temperature then evaporated under reduced pressure to give 2-
trifluoromethyl-[l,8]-naphthyridine-3-carbonyl chloride.
Stage 2
To a solution of tert. butyl 1-cyclopropyl-l-oxopropionate (1.53g) in dry methanol (48ml) under an atmosphere of nitrogen was added magnesium turnings (0.20g) and carbon tetrachloride (0.1ml). The mixture was stirred at ambient temperature until the magnesium had dissolved (ca. 3 hours). The solvent was evaporated under reduced pressure then toluene (ca. 50ml) was added and evaporated under reduced pressure to remove any residual methanol. Further toluene (30ml) was added and to this was added a suspension of the product from Stage 1 in toluene (30ml) followed by triethylamine (1.3ml). The mixture was stirred at ambient temperature for 18 hours, evaporated under reduced pressure, water added then it was extracted twice with ethyl acetate. The organic fractions were combined, washed with water then brine and dried over magnesium sulfate, filtered and evaporated under reduced pressure to give a red-brown oil. The oil was dissolved in toluene (60ml) containing p.toluene sulfonic acid (0.02g) then heated to reflux for 3 hours with stirring, cooled to ambient temperature then stored for 18 hours. The solution was purified by eluting down a column of silica with ethyl acetate to give an oil, 1.16g, containing l-cyclopropyl-3(2-trifluoromethyl-[l,8]-naphthyridin-3-yl)-propane-l,3-dione [1H NMR (CDCl3) δ: 9.29(1H, m), 8.50(1H, s), 8.36(1H, dd), 7.71(1H, m), 6.04(1H, s), 1.79(1H, m), 1.28(2H, m), 1.08(2H, m)] and an impurity of methyl 2- trifluoromethyl-[l,8]-
naphthyridine 3-carboxylate [1H NMR (CDC13) δ: 9.32(1H, m), 8.78(1H, s), 8.39(1H, dd), 7.71(1H, m), 4.04(3H, s)]. The material was used in Stage 3 without further purification.
Stage 3
The product from Stage 2 (0.50g) was dissolved in tetrahydrofuran (4ml) containing
acetic acid (0.19g) with stirring and cooled to 5°C then a solution of N,N-
dimethylformamide dimethylacetal (0.38g) in tetrahydrofuran (1ml) was added
dropwise. The mixture was stirred for 30 minutes at 5°C, allowed to warm to ambient
temperature, stirred for a further 30 minutes then poured into water. The mixture was
extracted twice with ethyl acetate, the extracts combined, washed with brine, dried
over magnesium sulfate, filtered and evaporated under reduced pressure to give a dark
red-brown gum. The gum was purified by chromatography (silica, ethyl acetate then
10% methanol in ethyl acetate) to give l-cyclopropyl-2-(l-
dimethylammomethylidene)-3-(2-trifluorom
1,3-dione as a dark-red gum, (0.33g). 1H NMR (CDC13) δ: 9.26(1H, m), 8.29(1H, s),
8.26(1H, dd), 7.65(1H, m), 7.48(1H, bs), 3.27(3H bs), 2.88(3H, bs), 2.03(1H, bs),
0.90(2H,bs),0.62(2H,bs).
Stage 4
To a stirred solution of l-cyclopropyl-2-(l-dimethylaminomethylidene)-3-(2-trifluoromethyl-[l,8]-naphthyridin-3-yl)-propane-l,3-dione (0.33g) in ethanol (10ml) was added hydroxylamine hydrochloride (0.069g). The mixture was stirred at ambient temperature for 3 hours, evaporated under reduced pressure and water added. The mixture was extracted three times with dichloromethane, the extracts combined, washed with water then brine, dried over magnesium sulfate, filtered and evaporated under reduced pressure to give a pale pink solid. The solid was purified by chromatography (silica, ethyl acetate) to give (5-cyclopropyl-isoxazo-4-yl) (2-trifluoromethyl-[l,8]-naphthyridin-3-yl) ketone as a beige solid, 0.21g. lH NMR (CDC13) δ: 9.35(1H, m), 8.41(1H, s), 8.36(1H, dd), 8.15(1H, s), 7.75(1H, m), 2.67(1H, m), 1.41(2H, m), 1.28(2H, m).
Stage 5
The product from Stage 4 (0.10g) was dissolved in dichloromethane (3ml) containing triethylamine (0.1ml) and stirred at ambient temperature for 3 hours then evaporated under reduced pressure. The residue was dissolved in water, acidified with aqueous 2M hydrochloric acid and extracted twice with ethyl acetate. The extracts were combined, washed with water then brine, dried over magnesium sulfate, filtered and evaporated under reduced pressure. The residue was washed with a little diethyl ether and filtered to give the required product as a yellow solid, 0.052g. lH NMR (CDC13)
δ:9.36(1H, m), 8.57(1H, s), 8.39(H, dd), 7.74(1H, m), 2.40(1H, m), 1.54(2H, m), 1.40(2H, m).
Example 11
Preparation of 2-(8-methyl-7-oxo-7,8-dihydro-2-trifluoromethyl[1,8]naphthyridine-3-carbony)-cyclohexane-1,3-dione
To a stirred suspension of 2-(7-hydroxy-2-trifluoromethyl-[l,8]-naphthyridine-3-carbony)- cyclohexane-l,3-dione (0.200g) in dry 1,2-dimethoxyethane (10ml) cooled to 0°C was added drop-wise a solution of n-butyl lithium (0.875ml of 1.6M solution in hexanes). On complete addition, the resulting suspension was stirred for 5 mins at 0°C followed addition of methyl iodide (0.345ml). The suspension was then allowed to warm to ambient temperature, dry N,N-dimethylformamide (5ml) was added and the resulting solution was stirred for a further 2 hours. The mixture was diluted with ethyl acetate (20ml), washed with aqueous 2M hydrochloric acid (5ml) then water (2x10ml). The organic extract was separated, dried over magnesium sulfate, filtered and evaporated under reduced pressure to afford the required product, 0.153g. lH NMR (CDC13) δ: 16.80 (1H, s), 7.74 (1H, s), 7.65 (1H, d), 6.88 (1H, d), 4.77 (2H, t), 3.96 (3H, s), 2.83 (2H, t), 2.43 (3H, t), 2.07(2H, quintet). Molecular ion: (MH)+ 367.
In a similar procedure to Example 11, the following compounds were made from 2-(7-hydrooxy-2-trifluoromethyl-[l,8]-naphmyridine-3-carbony)-cyclohexane-l,3-dione and a suitable alkylating agent:
2-(8-Benzyl-7-oxo-7,8-dihydro-2-trifluoromethyl-[l,8]-naphmyridine-3-carbony)-cyclohexane-l,3-dione (from benzyl bromide), lH NMR (CDC13) δ:16.80(1H, s),
7.72(1H, s), 7.64-7.61(3H, m), 7.31-7.21(3H, m), 6.88(1H, d), 5.71(2H, s), 2.83(2H, t), 2.43(3H, t), 2.07(2H, quintet), Molecular ion: (MH)+ 443.
2<8-(But-2-ynyl)-7-oxo-7,8-dihydro-2-trmuoromethyl-[l,8]-naphthyridine-3-carbony)-cyclohexane-l,3-dione (from but-2-ynyl bromide), lHNMR (CDC13) δ: 16.80(1H, s), 7.75(1H, s), 7.65(1H, d), 6.88(1H, d), 5.24(2H, q), 2.84(2H, t), 2.44(3H, t), 2.08(2H, quintet),1.76(3H, t), Molecular ion: (MH)+ 405.
2-{8