The present invention relates to a novel process for preparing anthranilic diamides involving the preparation of aminophenyl. The present invention also relates to a novel process for preparing aminophenyl.
BACKGROUND OF THE INVENTION:
Anthranilic diamides are a commercially important class of synthetic insecticides that bind to the ryanodine receptor with selective potency against insect versus mammalian forms of the receptor. The first commercialized anthranilic diamide of this class, chlorantraniliprole, has exceptional activity against lepidopteran pests. The second anthranilic diamide product of the same class, cyantraniliprole, has excellent cross-spectrum activity against a range of insect orders, including both lepidopteran and hemipteran pests. The PCT publications WO2003015518, WO2003015519, WO2004067528, WO2005077934 and WO20100069502 disclose the use of anthranilic diamides for controlling invertebrate pests such as arthropods.
These anthranilic diamide compounds can be prepared from 3,5-substituted 2-amino-N-alkylbenzamide compounds as intermediates. The PCT publication WO2013007603 discloses a process for preparation of 2-amino-5-cyano-3-methyl(N-methyl)benzamide type compounds from 2-amino-5-cyano-3-methylbenzoic acid esters. Further, the synthesis of certain 3,5-substituted 2-amino-N-alkyl-benzamide compounds and their utility as intermediates for preparing corresponding insecticidal anthranilic diamide compounds has been disclosed in WO2004067528, WO2006068669, WO2006062978 and WO2012103436. Further, the process for the synthesis of cyano derivatives of anthranilic diamide compounds or cyano functions containing intermediates thereof are disclosed in PCT publications WO2008010897, WO2008070158, WO2009085816, WO2009061991, WO2009006061 and WO2008082502.
However, the processes described in the above mentioned literature are laborious, and there is still a need to find a simple, efficient and industrially economical process for the preparation of anthranilic diamide compounds. Accordingly, the present invention provides a simple, environment-friendly and cost-effective process for the preparation of anthranilic diamide compounds and intermediates thereof.

OBJECT AND SUMMARY OF THE INVENTION:
It is therefore an objective of the present invention to provide a novel and cost-effective process for the preparation of anthranilic diamide compounds of Formula (I).
Another objective of the present invention is to provide an industrially viable and convenient process for the preparation of anthranilic diamides of Formula (I).
Surprisingly, the present invention provides a solution to these objectives by providing a novel process that allows the preparation of anthranilic diamides by overcoming at least one of the shortcomings of the processes described in the prior art.
These objectives were achieved according to the present invention by providing a novel process for preparing a compound of Formula (I),

wherein,
R1 is CH3, Br or Cl;
R2 is F, Cl, Br, I, or CN;
R3a and R3b are independently H, C1-C4 alkyl, C3-C6 cycloalkyl or C3-C6 cycloalkyl-C1-C4 alkyl;
R3c is independently H or C1-C4 alkyl;
R4 is Cl, Br, CF3, OCF2H, OCH2CF3, C1-C4 haloalkyl or ;
R5 is F, Cl or Br;
R6 is H, F or Cl;
Z is CR7 or N; and
R7 is H, F, Cl or Br.
The process of the present invention comprises the step of obtaining a compound of Formula (VI) which is then converted into a corresponding aminophenyl of Formula (V);
, and ,
wherein, Y is CH3, O-C1-C6 alkyl, and NR3aR3b; R2 is H, F, Cl, Br, I, or CN; R1 and R3c are as defined herein before.
The preparation of aminophenyl of Formula (V) and anthranilic diamides of Formula (I) therefrom is novel and inventive.
DETAILED DESCRIPTION OF THE INVENTION:
GENERAL DEFINITIONS
The definitions provided herein for the terminologies used in the present disclosure are for illustrative purpose only and in no manner limit the scope of the present invention disclosed in the present disclosure.

As used herein, the terms “comprises”, “comprising”, “includes”, “including”, “has”, “having”, “contains”, “containing”, “characterized by” or any other variation thereof, are intended to cover a non-exclusive inclusion, subject to any limitation explicitly indicated. For example, a composition, mixture, process or method that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, mixture, process or method.

The transitional phrase “consisting of” excludes any element, step or ingredient not specified. If in the claim, such would close the claim to the inclusion of materials other than those recited except for impurities ordinarily associated therewith. When the phrase “consisting of” appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole.

The transitional phrase “consisting essentially of” is used to define a composition or method that includes materials, steps, features, components or elements, in addition to those literally disclosed, provided that these additional materials, steps, features, components or elements do not materially affect the basic and novel characteristic(s) of the claimed invention. The term “consisting essentially of” occupies a middle ground between “comprising” and “consisting of”.

Further, unless expressly stated to the contrary, “or” refers to an inclusive “or” and not to an exclusive “or”. For example, a condition A “or” B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

Also, the indefinite articles “a” and “an” preceding an element or component of the present invention are intended to be nonrestrictive regarding the number of instances (i.e. occurrences) of the element or component. Therefore “a” or “an” should be read to include one or at least one, and the singular word form of the element or component also includes the plural unless the number is obviously meant to be singular.
Carbon-based radical refers to a monovalent molecular component comprising a carbon atom that connects the radical to the remainder of the chemical structure through a single bond. Carbon-based radicals can optionally comprise saturated, unsaturated and aromatic groups, chains, rings and ring systems, and heteroatoms. Although carbon-based radicals are not subject to any particular limit in size, in the context of the present invention they typically comprise 1 to 16 carbon atoms and o to 3 heteroatoms. The carbon-based radicals are selected from C1-C6 alkyl, C1-C6 haloalkyl and phenyl optionally substituted with 1-3 substituents selected from C1-C3 alkyl, halogen and nitro.
The meaning of various terms used in the description shall now be illustrated.
The term “alkyl”, used either alone or in compound words such as “alkylthio” or “haloalkyl” or -N(alkyl) or alkylcarbonylalkyl or alkylsuphonylamino includes straight-chain or branched C1 to C24 alkyl, preferably C1 to C15 alkyl, more preferably C1 to C10 alkyl, most preferably C1 to C6 alkyl. Representative examples of alkyl include methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl and l-ethyl-2-methylpropyl or the different isomers. If the alkyl is at the end of a composite substituent, as, for example, in alkylcycloalkyl, the part of the composite substituent at the start, for example the cycloalkyl, may be mono- or polysubstituted identically or differently and independently by alkyl. The same also applies to composite substituents in which other radicals, for example alkenyl, alkynyl, hydroxyl, halogen, carbonyl, carbonyloxy and the like, are at the end.
The term “cycloalkyl” means alkyl closed to form a ring. Representative examples include but are not limited to cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl. This definition also applies to cycloalkyl as a part of a composite substituent, for example cycloalkylalkyl etc., unless specifically defined elsewhere.
The term “cycloalkylalkyl” means cycloalkyl substituent on alkyl, for example, cyclopropyl or cyclobutyl or cyclopentyl are substituted on any carbon of C1-C6 alkyl.
The present invention relates to a process for preparing anthranilic diamide compound of Formula (I),

wherein,
R1 is CH3, Br or Cl;
R2 is F, Cl, Br, I, or CN;
R3a and R3b are independently H, C1-C4 alkyl, C3-C6 cycloalkyl or C3-C6 cycloalkyl-C1-C4 alkyl;
R3c is independently H or C1-C4 alkyl;
R4 is Cl, Br, CF3, OCF2H, OCH2CF3, C1-C4 haloalkyl or ;
R5 is F, Cl or Br;
R6 is H, F or Cl;
Z is CR7 or N; and
R7 is H, F, Cl or Br.
The process of the present invention is described herein after.
Initially, an aniline of Formula (VII), is acylated using a suitable acylating agent and optionally a suitable reagent to obtain a compound of Formula (VI),

wherein, Y is CH3, O-C1-C6 alkyl, and NR3aR3b; R2 is H, F, Cl, Br, I, or CN R1, R2 and R3c are as defined herein before.
The acylation of the aniline of Formula (VII) is carried out at a temperature ranging from 0 ? to 100 ? in the presence of one or more suitable solvent/s.
Non limiting examples of the suitable solvent useful for the purpose of acylating the aniline of Formula (VII) include aliphatic hydrocarbons such as hexane, heptane, octane, nonane, decane, dodecane and the like; alicyclic hydrocarbons such as cycloalkanes: cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, and the like; aromatic hydrocarbons such as toluene, xylene, mesitylene, benzene and the like; ethers such as diisopropyl ether, t-butyl methyl ether, tetrahydrofuran, 2-methyl tetrahydrofuran, dioxane, monoglyme, diglyme, methoxy-methane, methoxy-ethane ethoxy-ethane, di-methoxyethane, di-ethoxyethane and the like; halogenated hydrocarbons such as dichloromethane, chloroform, dichloroethane and like; polar aprotic solvents such as N,N-dimethylmethanamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, hexamethylphosphoramidem, 1,3-dimethyl-2-imidazolidinone and the like; and water.
Non limiting examples of the suitable acylating agent useful for the purpose of acylating the aniline of Formula (VII) include acyl halide, acetic acid, ethenone, and acetic anhydride.
Non limiting examples of the suitable reagents useful for supporting the acylation of the aniline of Formula (VII) is selected from the group consisting of alkylamines, dialkylamines, trialkylamines, pyridine, halogenated pyridines, 3-picoline, 4-picoline, quinoline, quinaldine, and alkylpyridines for example 2,6-dimethylpyridine, 2-methyl-5-ethylpyridine, and 2,3-dimethylpyridine, ammonia, ammonium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, calcium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, cesium carbonate, cesium bicarbonate, 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide, N,N'-Diisopropylcarbodiimide, O-(7-Azabenzotriazol-1-yl)-N,N,N’,N’-tetramethyluronium hexafluorophosphate (HATU), O-(7-Azabenzotriazol-1-yl)- N,N,N’,N’-tetramethyluronium tetrafluoroborate (TATU), O-(6-Chlorobenzotriazol-1-yl)-N,N,N’,N’-tetramethyluronium hexafluorophosphate (HCTU), O-(N-Suc-cinimidyl)-1,1,3,3-tetramethyl-uronium tetrafluoroborate (TSTU), O-(5-Norbornene-2,3-dicarboximido)-N,N,N’,N’-tetramethyluronium tetrafluoroborate (TNTU), O-(1,2-Dihydro-2-oxo-1-pyridyl-N,N,N’,N’-tetramethyluronium tetrafluoroborate (TPTU), 3-(Diethylphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one (DEPBT), (Benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP), (Benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate (PyBOP), (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate (PyAOP), Bromotripyrrolidinophosphonium hexafluorophosphate (PyBrOP), O-(Benzotriazol-1-yl)-N,N,N’,N’-tetramethyluronium hexafluorophosphate (HBTU) and O-(Benzotriazol-1-yl)- N,N,N’,N’-tetramethyluronium tetrafluoroborate (TBTU).
The compound of Formula (VI), wherein Y is O-C1-C6 alkyl and NR3aR3b, is obtained by the processes reported in literature.
For example, the compound of Formula (VI), wherein Y is O-C1-C6 alkyl, is obtained by reacting the corresponding aniline of Formula (VII) with dialkyl carbonate as reported in WO2108210711 or with alkyl chloroformate as reported in WO2016168098. Another process is reported in the article titled Synthesis of methyl n-phenyl carbamate by amino-transesterification, Zhang, Guangxu et al, From Wuhan Ligong Daxue Xuebao, Volume 33(6), page no. 36-39; 2011.
The compound of Formula (VI), wherein Y is NR3aR3b, is obtained by reacting the corresponding aniline of Formula (VII) with methyl isocyanate as reported in the article titled Intramolecular Hydrogen Bonding in Medicinal Chemistry, Kuhn, Bernd et al, From Journal of Medicinal Chemistry, Volume 53(6), pages 2601-2611; 2010. Another process is reported Flash vacuum pyrolysis of 1,2,5-oxadiazole 2-oxides and 1,2,3-triazole 1-oxides, Mitchell, William R. and Paton, R. Michael, From ARKIVOC (Gainesville, FL, United States), Volume (10), pages 34-54; 2010. The compound of Formula (VI), wherein Y is NR3aR3b, is obtained by reacting the corresponding aniline of Formula (VII) with carbamic chlorides.
Subsequently, the compound of Formula (VI) is converted into aminophenyl of Formula (V) in the presence of one or more suitable solvent/s and optionally using one or more suitable reagent;
;
wherein, R2 is H, F, Cl, Br, I, or CN; Y, R1 and R3c are as defined herein before.
Non limiting examples of the suitable solvent useful for the purpose of converting the compound of Formula (VI) into aminophenyl of Formula (V) include aliphatic hydrocarbons such as hexane, heptane, octane, nonane, decane, dodecane and the like; alicyclic hydrocarbons such as cycloalkanes: cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, and the like; aromatic hydrocarbons such as toluene, xylene, mesitylene, benzene and the like; ethers such as diisopropyl ether, t-butyl methyl ether, tetrahydrofuran, 2-methyl tetrahydrofuran, dioxane, monoglyme, diglyme, methoxy-methane, methoxy-ethane ethoxy-ethane, di-methoxyethane, di-ethoxyethane and the like; halogenated hydrocarbons such as dichloromethane, chloroform, dichloroethane and like; polar aprotic solvents such as N,N-dimethylmethanamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, hexamethylphosphoramidem, 1,3-dimethyl-2-imidazolidinone and the like; and water.
Non limiting examples of the suitable reagent useful for the purpose of converting the compound of Formula (VI) into aminophenyl of Formula (V) include aluminum bromide, aluminum chloride, aluminum isopropoxide, boron trichloride, boron trichloride methyl sulfide complex, boron trifluoride acetic acid complex, boron trifluroride acetonitrile complex, boron trifluoride dibutyl etherate, boron trifluoride diethyl etherate, boron trifluoride-methanol solution, boron trifluoride methyl etherate, boron trifluoride methyl sulfide complex, boron trifluoride phenol complex, boron trifluoride propanol complex, boron trifluoride tetrahydrofuran complex, dicyclohexylboron trifluoromethanesulfonate, tin (IV) chloride, titanium (IV) chloride, titanium (IV) chloride tetrahydrofuran, titanium (IV) isopropoxide, iron (III) bromide, iron (III) chloride, ytterbium (III) chloride, ytterbium (III) trifluoromethanesulfonate, ytterbium (III) triflate, ytterbium pentafluorobenzoate, phosphorous pentaxoide/peracetic acid, phosphorous pentafluoride, and methane sulfonic acid.
In one embodiment, the conversion of the compound of Formula (VI) into aminophenyl of Formula (V) is carried out at a temperature ranging from 20 ? to 200 ?, optionally, at a pressure ranging from 0.5 kg/cm2 to 250 kg/cm2.
In another embodiment, the conversion of the compound of Formula (VI) into aminophenyl of Formula (V) is carried out photo chemically,

wherein, Y, R1, R2 and R3c are as defined herein before.
In a particular embodiment, the conversion of the compound of Formula (VI) into aminophenyl of Formula (V) is carried out photo chemically at a radiation of 10 nm to 400 nm and at a temperature ranging from 20 ? to 200 ?.
In yet another embodiment, the conversion of the compound of Formula (VI) into aminophenyl of Formula (V) is carried out in batch processes, semi-continuous processes, in continuous processes or in flow processes.
In one of the embodiments, when R2 is H, the compound of Formula (VI) and or aminophenyl of Formula (V) are halogenated using suitable halogenating agents such as HX, NaX, KX, CuX2, MgX2, CsX, ZnX2, SOCl2, SO2Cl2, COCl2, X2, C(=O)(OCl3)2, t-BuOCl, NaOCl, Chloramine-T, N-halosuccinamides, POX3, PX3, PX5 or metal halides; wherein X is Cl, Br, I or F.
In the subsequent step, aminophenyl of Formula (V), wherein Y is CH3 or O-C1-C6 alkyl, is converted into a compound of Formula (III),
,
wherein, R1, R2, and R3c are as defined herein before.
The conversion of aminophenyl of Formula (V) into the compound of Formula (III) is carried out at a temperature ranging from 20 ? to 200 ? in the presence of bromine or chlorine or iodine and an inorganic base which includes but is not limited to sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide or barium hydroxide.
The conversion of aminophenyl of Formula (V) into the compound of Formula (III) can also be carried out using the oxidation processes known in the literature.
The compound of Formula (III) can be converted into a compound of Formula (IV) by using any of the methods known in the prior art or as described in CN106146414A, WO2016131098, ACS Med. Chem. Lett., 2017, 8 (6), pp 678–681 and Chem. Commun., 2018, 54, 12766-12769,

wherein, R1, R2, and R3c are as defined herein before.
The compound of Formula (III) is then used in the synthesis of the compound of Formula (I). There are several ways for achieving the synthesis of compound of Formula (I) starting from compounds of Formula (III), having been reported in WO2012103436, WO2008010897 and WO2006062978.
In one of the ways, the compound of Formula (III) is converted into the compound of Formula (IV), followed by reacting the compound of formula (IV) with a compound of Formula (VIII) to obtain the compound of Formula (I),

wherein, R8 is hydroxy or halogen or C1-C6 alkoxy, and R1, R2, R3a, R3b, R3c, R4, R5, R6 and Z are as defined herein before.
In one embodiment, the compound of Formula (IV) may be isolated.
In another embodiment, the compound of Formula (IV) may not be isolated.
In another way, the compound of Formula (III) is reacted with a compound of Formula (VIII) to obtain the compound of Formula (IIA) or Formula (IIB; when R3c represents hydrogen),

Further, the compound of Formula (IIA) or Formula (IIB) is subsequently reacted with amine to obtain the compound of Formula (I),

wherein, R1, R2, R3a, R3b, R3c, R4, R5, R6, R8 and Z are as defined herein before.
The compound of Formula (II) may optionally be converted into the corresponding acyl halide before reacting with amine to obtain the compound of Formula (I).
The compound of Formula (III) may optionally be converted into the corresponding acyl halide before reacting acid of Formula (VIII) to obtain the compound of Formula (II).
In one embodiment, the compound of Formula (II) or the corresponding acyl halide derived from them may be isolated.
In another embodiment, the compound of Formula (II) or the corresponding acyl halide may not be isolated.
The present invention shall now be described in light of the following non-limiting examples.
EXAMPLES
Scheme 1:

Step-1
Synthesis of N-(4-chloro-2-methylphenyl)acetamide
Triethylamine (5.0 mL, 35.3 mmol) and acetyl chloride (3.0 mL, 42.4 mmol) were added sequentially to a stirred solution of 4-chloro-2-methylaniline (5 g, 35.3 mmol) in dichloromethane (20 mL) at 0 °C. The resulting reaction mixture was warmed to 25 ? and stirred further for 2 h. After completion of the reaction, the reaction mixture was diluted with dichloromethane (50 mL) and washed successively with water (50 mL) and brine solution (50 mL). Dichloromethane layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The product precipitated upon addition of n-hexane (100 mL) was filtered and dried under reduced pressure to obtain N-(4-chloro-2-methylphenyl)acetamide (5.8 g, 31.9 mmol, 90 % yield).
1HNMR (400 MHz, DMSO-d6) d 9.30 (s, 1H), 7.44 (d, J = 8.6 Hz, 1H), 7.27 (d, J = 2.1 Hz, 1H), 7.18 (dd, J = 8.6, 2.4 Hz, 1H), 2.18 (s, 3H), 2.04 (s, 3H). GCMS: [183].
Step-2
Synthesis of 1-(2-amino-5-chloro-3-methylphenyl)ethan-1-one
A solution of N-(4-chloro-2-methylphenyl)acetamide (1 g, 5.5 mmol) in acetonitrile (50 mL) was degassed by sonication (20 min) and purging nitrogen gas for 5 min. The solution was filled in a quartz flask and kept in a UV chamber for irradiation at 254 nm and 25 ? for 24 h. After 24 h, 20% of desired product was formed along with 5% of 2-methyl-4-chloroaniline confirmed by LCMS. The reaction mixture was concentrated and was purified by CombiFlash system using 5-10% Ethyl acetate: Hexane to obtain 1-(2-amino-5-chloro-3-methylphenyl)ethan-1-one.
1HNMR (400 MHz, CHLOROFORM-D) d 7.73-7.54 (1H), 7.25-7.06 (1H), 6.21 (s, 2H), 2.71-2.58 (3H), 2.22-2.06 (3H). LCMS: [184.04]M+1
Step-3
Synthesis of 2-amino-5-chloro-3-methylbenzoic acid
To a stirred solution of sodium hydroxide (54.5 mg, 1.4 mmol) in water (1 mL) and dioxane (0.5 mL), bromine (0.22 mL, 0.4 mmol) was added drop wise over 5 min at 0 °C. 1-(2-Amino-5-chloro-3-methylphenyl)ethan-1-one (25 mg, 0.14 mmol) in dioxane (0.5 mL) was added drop wise and stirred for 5 h at 25 ?. After completion of the reaction, the reaction mixture was acidified (to pH 3) with 2 M hydrochloric acid and extracted with ethyl acetate (2 x 15 mL). The combined ethyl acetate layers were washed with brine (10 mL), dried over anhydrous sodium sulphate and concentrated under reduced pressure. The product was precipitated by the addition of n-hexane (20 mL). The resultant product was filtered and dried under reduced pressure to obtain 2-amino-5-chloro-3-methylbenzoic acid (15 mg, 0.11 mmol, 59 % yield).
1HNMR (400 MHz, DMSO-d6) d 7.54 (d, J = 2.4 Hz, 1H), 7.22 (t, J = 1.8 Hz, 1H), 2.10 (s, 3H).

,CLAIMS:We Claim:
1. A process for preparing a compound of Formula (I),

wherein,
R1 is CH3, Br or Cl;
R2 is H, F, Cl, Br, I, or CN;
R3a and R3b are independently H, C1-C4 alkyl, C3-C6 cycloalkyl or C3-C6 cycloalkyl-C1-C4 alkyl;
R3c is independently H or C1-C4 alkyl;
R4 is Cl, Br, CF3, OCF2H, OCH2CF3, C1-C4 haloalkyl or ;
R5 is F, Cl or Br;
R6 is H, F or Cl;
Z is CR7 or N; and
R7 is H, F, Cl or Br;
said process comprising the steps of:
a) obtaining a compound of Formula (VI) by acylating a compound of Formula (VII) in a suitable solvent using suitable acylating agent;

wherein, Y is CH3, O-C1-C6 alkyl and NR3aR3b; R1, R2 and R3c are as defined herein above;
b) converting compound of Formula (VI) to compound of Formula (V) in at least one suitable solvent, optionally using at least one reagent;

wherein, Y, R1, R2 and R3c are as defined herein above;
c) converting compound of Formula (V) to compound of Formula (III)

wherein Y, R1, R2 and R3c are as defined herein above;
d) converting compound of Formula (III) to compound of Formula (IV) using amine;

wherein,
the compounds of Formula IV may or may not be isolated,
R1, R2, R3a, R3b and R3c are as defined herein above,
or;
reacting compound of Formula (III) with compound of Formula (VIII) to obtain compound of Formula (IIA) or Formula (IIB); ;

wherein,
the compounds of Formula II may or may not be isolated,
R8 is hydroxy or halogen or C1-C6 alkoxy, and R1, R2, R3c, R4, R5, R6 and Z are as defined herein above;
e) reacting compound of Formula (IV) with compound of Formula (VIII) to obtain compound of formula (I);

wherein,
the compounds of Formula (IV) may or may not be isolated,
R8 is hydroxy or halogen or C1-C6 alkoxy, and R1, R2, R3a, R3b, R3c, R4, R5, R6 and Z are as defined herein above,
or;
converting compound of Formula (II) to compound of Formula (I) using amine,

wherein,
the compounds of Formula (IIA) or Formula (IIB) may or may not be isolated,
R1, R2, R3a, R3b, R3c, R4, R5, R6 and Z are as defined herein above.
2. The process as claimed in claim 1, wherein the suitable solvent in steps (a), (b), (c) and (d) is selected from the group consisting of aliphatic, alicyclic or aromatic hydrocarbons, halogenated hydrocarbons, ethers, nitriles, amides, alcohols or combinations thereof.
3. The process as claimed in claim 1, wherein the suitable solvent in steps (a), (b), (c) and (d) is selected from the group consisting of hexane, heptane, octane, nonane, decane, dodecane, cycloalkanes: cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, toluene, xylene, mesitylene, benzene, diisopropyl ether, t-butyl methyl ether, tetrahydrofuran, 2-methyl tetrahydrofuran, dioxane, monoglyme, diglyme, methoxy-methane, methoxy-ethane ethoxy-ethane, di-methoxyethane, di-ethoxyethane, dichloromethane, chloroform, dichloroethane, N,N-dimethylmethanamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, hexamethylphosphoramidem, 1,3-dimethyl-2-imidazolidinone or combinations thereof.
4. The process as claimed in claim 1, wherein,
i. the step (a) is carried out at a temperature ranging from 0 ? to 100 ?; and
ii. the suitable acylating agent in step (a) is selected from the group consisting of acyl halide, acetic acid, ethenone, and acetic anhydride;
5. The process as claimed in claim 1, wherein step (a) is carried out in presence of suitable reagent selected from alkylamines, dialkylamines, trialkylamines, pyridine, 2,6-dimethylpyridine, 2-methyl-5-ethylpyridine, and 2,3-dimethylpyridine, ammonia, ammonium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, calcium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, cesium carbonate, cesium bicarbonate. 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide, N,N'-Diisopropylcarbodiimide, and O-(7-Azabenzotriazol-1-yl)-N,N,N’,N’-tetramethyluronium hexafluorophosphate (HATU).
6. The process as claimed in claim 1, wherein,
i. the step (b) is carried out at a temperature ranging from 20 ? to 200 ? and a pressure ranging from 0.5 kg/cm2 to 250 kg/cm2; or
ii. the step (b) is carried out photochemically at a radiation of 10 nm to 400 nm and at a temperature ranging from 20 ? to 200 ?; and
7. The process as claimed in claim 1, wherein, step (b) is carried out in presence of suitable reagent selected from aluminum bromide, aluminum chloride, aluminum isopropoxide, boron trichloride, boron trichloride methyl sulfide complex, boron trifluoride acetic acid complex, boron trifluroride acetonitrile complex, boron trifluoride dibutyl etherate, boron trifluoride diethyl etherate, boron trifluoride-methanol solution, boron trifluoride methyl etherate, boron trifluoride methyl sulfide complex, boron trifluoride phenol complex, boron trifluoride propanol complex, boron trifluoride tetrahydrofuran complex, dicyclohexylboron trifluoromethanesulfonate, tin (IV) chloride, titanium (IV) chloride, titanium (IV) chloride tetrahydrofuran, titanium (IV) isopropoxide, iron (III) bromide, iron (III) chloride, ytterbium (III) chloride, ytterbium (III) trifluoromethanesulfonate, ytterbium (III) triflate, ytterbium pentafluorobenzoate, phosphorous pentaxoide/peracetic acid, phosphorous pentafluoride, and methane sulfonic acid.
8. The process as claimed in claim 1, wherein,
i. the step (c) is carried out at a temperature ranging from 20 ? to 200 ?; and
ii. the step (c) is carried out in the presence of bromine or chlorine or iodine and an inorganic base selected from sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide or barium hydroxide.
9. The process as claimed in claim 1, wherein compound of Formula (VI) and (V), having R2 = H, are halogenated using suitable halogenating agents selected from HX, NaX, KX, CuX2, MgX2, CsX, ZnX2, SOCl2, SO2Cl2, COCl2, X2, C(=O)(OCl3)2, t-BuOCl, NaOCl, Chloramine-T, N-halosuccinamides, POX3, PX3, PX5 or metal halides; wherein X is Cl, Br, I or F.