The present invention relates to a process for the synthesis of derivatives of specially substituted azole compounds which have improved antifungal activiity as compared with presently available agents in this class.
This invention also relates to pharmaceutical preparations containing the compounds of the present invention and their use in treating and/or preventing the fungal infections in mammals, preferably humans.
Life threatening systemic fungal infections continue to be a significant problem in health care. In particular, patients who become immunocompromised as a result of diabetes, cancer, prolonged steroid therapy, organ transplantation anti-rejection therapy, the acquired immune deficiency syndrome (AIDS) or other physiologically or immunologically comprising syndromes, are especially susceptible to opportunistic fungal infections.
Since the 1950s and 1960s and until recently, the key opportunistic fungal pathogens with which clinicians had to contend were Candida albicans, Asperigillus fumigatus, and the zygomiycetes, which cause mucormycosis, a rapidly fatal infection especially in diabetic patients. Today, non-albicans Candida have become more frequent, as have other Aspergillus species. Candida species are now the fourth most common cause of nosocomial blood stream infection and they are associated with an extremely high mortality rate of 40%. From 1980 to 1990, the incidence of fungal infections in US hospitals nearly doubled, from 2.0 to 3.8% of patients discharged. The most marked increase in fungal infection rates occurred not only in transplant units or oncology centers, but also in surgical services. These changing patterns demonstrate that fungal infections are no longer limited to the most severly immunosuppressed patients.
During the past two decades, a substantial shift in the epidemiology of candidemia due to different Candida species has occurred. In the 1960s and 1970s, Candida albicans accounted for 85-90% of cases of candidemia. In 1999, however, only 42% of candidemia cases were caused by C. alibicans, while non-albicans Candida accounted for the remainder.
Cryptococosis is a leading cause of morbidity among the AIDS patients. The incidence of life threatening cryptococcal infection among these patients have been estimated to vary from 10 to 30%; 10-20% of these patients die during the initial therapy, and 30 to 60%

patients succumb within a year. Penicillinium marneffei has been frequently isolated from HIV+ patients, especially in Southeast Asia.
The most common causative agent of mucormycosis is rhizopus, a common bread mould that lives on any organic material. Other pathogens include Mucor, Rhizomucor and Absidia. Zygomycetes include twenty different fungi, all appearing the same histologically. The severely immunocompromised patient may become infected with zygomycetes via respiratory inhalation.
Fusarium is the most prevalent plant fungus worldwide, and it is now recognized as human pathogen as well. Fusarium infections can occur in immunocompetent or immuno suppressed individuals. Fusarium infection is life-threatenning and associated with a poor prognosis.
Penicillium marneffei is an environmental fungi that can cause serious, life-threatening infections in immunosuppressed patients. Penicillium marneffei has gained particular attention during the AIDS pandemic, as it may produce disease that is clinically indistinugishable from disseminated histoplasmosis.
Invasive aspergillosis has become a leading cause of death, mainly among patients suffering from acute leukaemia or after allogenic bone marrow transfusion and after cytotoxic treatment of these conditions. It also occurs in patients with condition such as AIDS and chronic granulomatous disease. At present, only Amphotericin B and Itraconazole are available for treatment of aspergillosis. In spite of their activity in vitro, the effect of these drugs in vivo against Aspergillus fumigatus remains low and as a consequence mortality from invasive aspergillosis remains high.
Over the last three decades important progress has been made in the therapy of systematic fungal infections. Although chemotherapeutic agents such as flucytosine and potassium iodide are effective against selected fungal diseases, the primary drugs used to treat systemic mycoses are amphotericin B and the azole compounds. Despite the general effectiveness of amphotericin B, it is associated with a number of complications and unique toxicities that limit its use. Furthermore, the drug is poorly absorbed from the gastrointestinal tract necessitating intravenous administration. In addition, amphotericin B penetrates poorly into cerebrospinal fluid (CSF) of both normal and inflamed meninges.

The problems associated with amphotericin B have stimulated search for new agents. Within the available drugs to treat fungal infections, the azole class appears to be the most promising. This class of compounds inhibits the biosynthesis of ergosterol in fungi, which is the main constituent of fungal cell membrane. Of the various representative antifungals, early azoles include clotrimazole, miconazole, and tioconazole, which were potent against a wide range of fungi pathogenic to human. Clortrimazole was the first oral azole proven to be effective in experimental and human mycosis. However, brief courses of treatment with clotrimazole lead to the induction of liver microsomal enzymes which in turn increase the metabolism of the drug, thereby diminishing its antifungal activity. In contrast, miconazole, which became available around the same time as clotrimazole, is not rapidly metabolized and is an effective intravenous therapy for many systemic fungal diseases. Unfortunately, the use of miconazole is limited by its multiple toxic effects.
The in-vitro activity of clotrimazole, miconazole and tioconazole was not well exhibited in in-vivo models due to poor oral bioavailability and metabolic vulnerability. Ketoconazole was the first drug that could be used against systemic fungal infection and successfully delivered through oral route. However, it was still quite susceptible to metabolic inactivation and also caused impotence and gynacomastia probably due to its activity against human cytochrome P450 enzymes. In addition to its potential toxicity, several well described drug interactions with ketoconzole have been documented.
Even with the advent of ketoconazole, the search for improved antifungal azole agents has continued due in part to concerns over the potential for toxicity and poor penetration into cerebrospinal fluid (CSF) associated with ketoconazole. Several azoles have been developed as topical agents primarily directed at superficial candidal and dermatophytic infections.
Fluconazole is the current drug of choice for treatment of severe infections caused by Candida species and C.neoformans. However, fluconazole has only weak activity against isolates of Aspergillus species [minimum inhibitory concentration (MIC) values are of the order of 400µg/ml], since the drug has low potency (IC50=4.8µM) against lanosterol 14α-de-methylase, the target enzyme in the fungus. Itraconazole, another triazole antifungal compound, generally is more active than fluconazole in the treatment of aspergillosis, but

its activity in the clinic remains mixed as it showed variable oral availability, low solubility and very high protein binding besides causing ovarian cancer in animals.
The development of the earlier compounds which included SCH 39304 (Genoconazole), SCH 42427 (Saperaconazole) and BAY R 8783 (Electrazole) had to be discontinued as a result of safety concerns. Another promising triazole, D0870, a derivative of fluconazole, exhibited significant variations in plasma pharmacokinetics besides having weak anti-Aspergillus activity. Other fluconazole derivatives in different stages of development include Voriconazole and ER 30346 (BMS 207147). Voriconazole also shows non-linear pharmacokinetics besides some concern regarding its ocular toxicity. ER 30346's anti-aspergillus activity, both in-vitro and in-vivo, is at best, only equal to itraconazole's activity. SCH 56592 is a hydroxylated analogue of itraconazole with potent in-vitro and in-vivo activity, but is undetectable in CSF even when the serum drug concentration after several days of treatment are 25 to 100 times above the MIC for the most resistant C. neoformans. Thus, the potent activity of SCH 56592 for C. neoformans is partially negated by its low concentration at the site of infection in the central nervous system. The above candidates of azoles are discussed in the following publications:
SCH 56592; Antimicrobial agents and chemotherapy, 40, 1910 (1996); 36th
Interscience Confernece on Antimicrobial agents and chemotherapy, September,
1996, New Orleans, Abst. To F-87-F-102.
TAK-187; 36th Interscience Conference Antimicrobial agents and Chemotherapy,
September, 1996, New Orleans, Abst. F 74; EP 567892.
TAK- 456 and TAK -457; 40th Interscience Conference on Antimicrobial agents and
chemotherapy. Toronto, Canada, Abs. No. 1085 and 1086; US 6,034,248.
ER-30346 : Drugs of the Future. 21. 20 (1996).
Various derivatives of azole compounds have been covered in US Pat. No. 5,371,101 assigned to Takeda. But none of them satisfies the medical needs completely, as they offer a limited spectrum of activity and low potency.
Thus, the antifungals in the market suffer with drawbacks such as toxicity, narrow spectrum of activity and fungistatic profile rather than fungicidal. Some of them also exhibit drug -drug interactions and as a result, therapy becomes complex. In view of the high incidence of fungal infections in immunocompromised patients and the recent trends

for the steady increase of the population of such patients, demands for new antifungal agents with broad spectrum of activity and good pharamcokinetic properties has increased. Thus, the continuing demand for safe and effective broad spectrum antifungal agent with favourable pharmacokinetic properties has spurred both the design and development of new systemically active antifungal triazoles.
Despite the therapeutic success of fluconazole and itraconazole, there remains a significant need for improved, broad spectrum, fungicidal rather than fungistatic, better tolerated, less toxic, safe at efficacious doses and more potent antifungal compounds with minimal potential for development of resistance among traget fungi. Therefore, development of antifungal agents is still a big challenge.
An object of the present invention is to provide a process for the synthesis of compounds of Formula I, as shown in the accompanied drawings and its pharmaceutically acceptable salts, enantiomers, diastereomers, N-oxides, prodrugs or metabolities, which overcome the problems associated with the azole compounds described in the prior art wherein
X is selected from the group consisting of CH2, CO, CS and SO2;
Ar is a substituted phenyl group having one to three substituents independently selected from a halogen (e.g., fluorine, chlorine, bromine, or iodine), C1-C4alkyl, halogenated lower (C1-C4) alkyl group and halogenated lower (C1-C4) alkoxy group such as 2,4-difluorophenyl, 2,4-dichlorophenyl, 4-chlorophenyl, 4-fluorophenyl, 2-chlorophenyl, 2-fluorophenyl, 4-trifluoromethylphenyl, 2-fluoro-4-chlorophenyl, 2-chloro-4-fluorophenyl, 4-trifluoromethoxyphenyl, 2,4,6-trifluorophenyl, 4-bromophenyl;
RI and R2 are each independently selected from the group consisting of hydrogen, C1-C4 alkyl,C1-C4 alkoxy, amino, hydroxy, nitro, cyano, carboxyl, protected carboxyl, and SO2 R1 wherein R' is hydrogen, alkyl or aryl;
Y is a phenyl group which is unsubstituted or substituted by 1-3 substituents each independently selected from the group consisting of halogen, nitro.amino, cyano, carboxyl, protected carboxyl, hydroxy, C1-C4alkyl, C1-C4 alkoxy and SO2R' wherein R' is hydrogen, alkyl or aryl;

R3 is selected from the group consisting of hydrogen, C1-C4 alkyl group, C1-C4 alkoxy, nitro, amino, cyano, carboxyl, protected caboxyl and SO2R' wherein R' is hydrogen, alkyl or aryl, and
X1, X2, YI, Y2 and Z are independently selected from the group consisting of hydrogen halogen, nitro, cyano, amino, sulphonyl, aryl, C1-C4 alkyl, C1-C4 alkoxy, halogenated lower (C1-C4 ) alkyl group, halogenated lower (C1-C4) alkoxy group and carboxyl, or protected carboxyl.
When R! is other than hydrogen, Formula I has two asymmetric centers and there are four possible enantiomers i.e. RR, RS, SR and SS. This invention relates to the mixture of enantiomers as well as individual isomers and the most preferred isomer in this situation is RR.
According to the second aspect of the invention, there is provided a process for the preparation of compounds of Formula II, as shown in the accompanied drawings and its pharmaceutically acceptable salts, enantiomers, diastereomers, N-oxides, prodrugs or metabolities, wherein
X, Ar, RI, R2, X1, X2, Y1, Y2 and Z are the same as defined earlier.
When RI is other than hydrogen, Formula II has two asymmetric centres and there are four possible enantiomers i.e. RR, RS, SR and SS. This invention relates to the mixture of enantiomers as well as individual isomers and the most preferred isomer in this situation is RR.
Pharmaceutically acceptable, non-toxic acid addition salts of the compounds of the present invention of Formula I and II, as shown in the accompanied drawings may be formed with inorganic or organic acids, by methods well known in the art.
It is further object of the present invention to provide compositions containing the novel compounds of the present invention in the treatment of fungal infections.
The present invention also includes within its scope prodrugs of the compounds of Formulae I and II. In general, such prodrugs will be functional derivatives of these

compounds which readily get converted in-vivo into defined compounds. Conventional procedures for the selection and preparation of suitable prodrugs are known.
The invention also includes pharmaceutically acceptable salts, the enantiomers, diastereomers, N-oxides, prodrugs, metabolites in combination with pharmaceutically acceptable carrier and optionally included e-xcipient.
Other objects and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by the practice of the invention. The objects and advantages of the invention may be realised and obtained by means of the mechanisms and combinations pointed in the appended claims.
In order to achieve the above mentioned objects and in accordance with the purpose of the invention as embodied and broadly described herein, there are provided processes for the synthesis of compounds of Formulae I and II, as shown in Schemes I and II of the accompanied drawings, wherein X, Ar, RI, R2, R3,Y, X1, X2, YI, Y2 and Z are the same and defined earlier. The starting compounds of the Formulae III and IV are known from our copending Indian Patent Application No. 198/Del/2000 and US Patent No. 5,371,101, respectively and are hereby incorporated by reference.
SCHEME I
In Scheme I ( as shown in the accompanied drawings), there is provided a process for preparing a compound of Formula I, as shown in the accompanied drawings and its pharmaceutically acceptable salts, enantiomers, diastereomers, N-oxides, prodrugs, or metabolites, wherein
X is selected from the group consisting of CH2, CO, CS and SO2;
Ar is a substituted phenyl group having one to three substituents independently selected from a halogen (e.g., fluorine, chlorine, bromine, or iodine) C1-C4 alkyl, halogenated lower (C1-C4) alkyl group and halogenated lower (C1-C4) alkoxy group such as 2,4-difluorophenyl, 2,4-dichlorophenyl, 4-chlorophenyl, 4-fluorophenyl, 2-chlorophenyl, 2-fluorophenyl, 4-trifluoromethylphenyl, 2-fluoro-4-chlorophenyl, 2-chloro-4-fluorophenyl, 4-trifluoromethoxyphenyl, 2,4,6-trifluorophenyl, 4-bromophenyl;
R1 and R2 are each independently selected from the group consisting of hydrogen, C1-C4 alkyl, C1-C4alkoxy, amino, hydroxy, nitro, cyano, carboxyl, protected carboxyl, and SO2 R' wherein R' is hydrogen, alkyl or aryl;
Y is a phenyl group which is unsubstituted or substituted by 1-3 substituents each independently selected from the group consisting of halogen, nitro.amino, cyano, carboxyl, protected carboxyl, hydroxy, C1-C4 alkyl,C1-C4 alkoxy and SO2R' wherein R1 is hydrogen, alkyl or aryl;
R3 is selected from the group consisting of hydrogen, C1-C4 alkyl group,C1-C4alkoxy, nitro, amino, cyano, carboxyl, protected caboxyl and SO2R' wherein R' is hydrogen, alkyl or aryl, and
X1, X2, YI, Y2 and Z are independently selected from the group consisting of hydrogen halogen, nitro, cyano, amino, sulphonyl, aryl, C1-C4 alkyl, C1-C4 alkoxy, halogenated lower (C1-C4) alkyl group, halogenated lower (C1-C4) alkoxy group and carboxyl, or protected carboxyl.
When RI is other than hydrogen, Formula I has two asymmetric centers and there are four possible enantiomers i.e. RR, RS, SR and SS. This invention relates to the mixture of enantiomers as well as individual isomers and the most preferred isomer in this situation is RR;
which comprises reacting the appropriate oxo compound of Formula III, as shown in the accompanied drawings, wherein X, Ar, R1, R2, Y, R3, X1, X2) Y1, Y2 and Z have the same meanings as defined above, with modified Lawesson's reagent of Formula V, as shown in the accompanied drawings to afford the desired compound of Formula I. The oxo compound of Formula III may be prepared according to the procedure as disclosed in our copending Indian Patent Application No. 198/Del/2000. The modified Lawesson's reagent is prepared according to the procedure as disclosed by Masataka Yokohamna et al. in Synthesis, pp 827-829 (1984).
SCHEME II
In Scheme II (as shown in the accompanied drawings) there is provided a process for preparing a compound of Formula II, as shown in the accompanied drawings and its pharmaceutically acceptable salts, enantiomers, diastereomers N-oxides, prodrugs or metabolities wherein
X is selected from the group consisting of CH2, CO, CS and SO2;
Ar is a substituted phenyl group having one to three substituents independently selected from a halogen (e.g., fluorine chlorine bromine or iodine),C1-C4 alkyl, halogenated lower (C1-C4) alkyl group and halogenated lower (C1-C4) alkoxy group such as 2,4-difluorophenyl, 2,4-dichlorophenyl, 4-chlorophenyl, 4-fluorophenyl, 2-chlorophenyl, 2-fluorophenyl, 4-trifluoromethylphenyl, 2-fluoro-4-chlorophenyl, 2-chloro-4-fluorophenyl, 4-trifluoromethoxyphenyl, 2,4,6-trifluorophenyl, 4-bromopheyl;
R1 and R2 are each independently selected from the group consisting of hydrogen, C1-C4 alkyl, C1-C4 alkoxy, amino, hydroxy, nitro, cyano, carboxyl, protected carboxyl, and S02 R' wherein R' is hydrogen, alkyl or aryl; and
X1 X2, YI, Y2 and Z are independently selected from the group consisting of hydrogen halogen, nitro, cyano, amino, sulphonyl, aryl, C1-C4, alkyl,C1-C4 alkoxy, halogenated lower (C1-C4) alkyl group, halogenated lower (C1-C4) alkoxy group and carboxyl, or protected carboxyl.
When RI is other than hydrogen, Formula I has two asynmetric centers and ther are four possible enantiomers i.e. RR, RS, SR and SS. This invention relates to the mixture of enantiomers as well as individual isomers and the most preferred isomer in this situation is RR;
with modified Lawesson's reagents [prepared according to the procedure as disclosed by Masataka Yokohama et al in Synthesis, pp 827-829 (1984)] of Formula V, as shown in the accompanied drawings, to afford the desired compound of Formula II. The starting compound of Formula IV is prepared by following the procedure as disclosed in the US Pat. No. 5,371,101.
In the above synthesis where specific solvent and specific modified Lawesson's reagent are mentioned, it is to be understood that other solvents and Lawesson's reagent or modification thereof may be used. Similarly, the reaction temperature and duration of the reaction may be adjusted according to the need. The compounds which are capable of being produced by Schemes I and II, according to the present invention include
Compound No. 1 : 2-{[1R2R]-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazole-1-yl)propyl}-4-{4-[4-(4-chlorophenyl)-1-piperizinyl]phenyl}-3-(2H,4H)-1,2,4-thiotriazolone
Compound No. 2 : 2-{[1R2R]-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazole-1-yl)propyl}-1-[4-(4-methoxyphenyl)-3-(2H,4H)-1,2,4-thiotriazolone
The examples mentioned below demonstrate the general synthetic procedure and should not be constraint to limit the scope of the present invention.
The compounds were characterized using NMR, IR and were purified by chromatography. Crude products were subjected to column chromatographic purification using silica gel (100-200 or 60 -120 mesh) as stationary phase.
EXAMPLE Typical procedure for the preparation of compounds of Formula I
A mixture of the appropriate oxo compound (1.15 mmol) and modified Lawesson's reagent (6.34 mmol) in toluene (140 mL) was heated at 120°C (bath temperature) for 3.5 hours. The reaction mixture was then cooled to room temperature, and the solvent was removed in vacua. The residue thus obtained was washed several times with dichloromethane. The dichloromethane soluble fractions were combined and concentrated in vacua. Purification by column chromatography (100-200 mesh silica gel, 10-15% ethyl acetate/dichloromethane) afforded the desired sulfur analog in 44.5% yield and ~90% HPLC purity. Re-crystallization with absolute ethanol afforded the pure compound in about 98% purity (by HPLC).
Typical procedure for the preparation of compounds of Formula II
The oxo compound (1 mol) and Lawesson's Reagent (2 mol equivalent.) were dried under high vacuum for 10min, flushed with nitrogen and heated to reflux in toluene for 15 hours. Reaction mixture was concentrated to dryness, re-dissolved in dichloromethane and purified by column chromatography (silica gel, 100-200 mesh), using dichloromethane-ethyl acetate mixtures (9.5:0.5 to 6:4) to afford the desired product in about 10% yield.
Assignment of RR/SS was done on the basis of 1HNMR analysis. The compounds of the invention which were synthesised by one or more of the above described methods is given below alongwith their 1HNMR data. All 1HNMR spectra were recorded on Brucker AMX 300 NMR machines (300 MHZ) using CDCI3 as a solvent and IMS as an internal standard unless otherwise specified. All values are given in ppm.
Symbols in the examples have the meanings; s:singlet; d: doublet; t: triplet; q: quartnet; dd: double doublet; m:multiplet; brbroad; J:coupling constant:
Compound No. 1 : 2-{[1R2R]-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazole-1 -yl)propyl}-4-{4-[4-(4-chlorophenyl)-1 -piperizinyl]phenyl}-3-(2H,4H)-1,2,4-thiotriazolone
m.p.: 129-130°C
IR (KBr): 3421, 2916, 2847, 1614, 1595 cm-1
NMR (300 MHz, CDCI3): δ 1.33 (d, J=6.7 Hz, CH-CH3), 3.33-3.42 (m, 8H, piperazine-H), 4.35 (d,
J=14.3 Hz, 1H, CH2-Triazole), 5.14 (d, J=14.4 Hz, CH2-Triazole), 5.19 (bs, 1H, -OH), 5.93 (q,
J=6.7 Hz, 1H, CH-CH3), 6.81-6.90 (m, 4H, Ar-H), 7.05 (d, J=8.6 Hz, 2H, Ar-H), 7.24 (d, J=8.5 Hz,
2H, Ar-H), 7.43 (d, J=8.5 Hz, 2H, Ar-H), 7.60 (m, 1H, 2,4-difluorophenyl-H), 7.74 (s, 1H,
thiotriazolone-H), 7.92 (s, 1H,triazole-H), and 7.93 (s, 1H, triazole-H).
Mass: m/z 623.1 (M+1)
Compound No. 2 : 2-{[1R2R]-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazole-1 -yl)propyl}-1 -[4-(4-methoxyphenyl)-3-(2H,4H)-1,2,4-thiotriazolone
m.p.: 166-170°C
IR (KBr): 3436, 2924, 1615, 1511, 1476, 1258, 962 and 835 cm-1
NMR (CDCI3): δ1.36 (d, 1H, J=9 Hz; CH-CH3), 3.873 (s, 3H; OCH3), 4.351 (d, 1H, J=14.4
Hz; triazole-CH2), 5.703-5.202 (m, 2H; triazole-CH2 & OH), 5.933 (q, 1H, J=6.9 Hz, CH-CH3), 6.81-6.87 (m, 2H; Ar-H), 7.034-7.07 (d, 2H; Ar-H), 7.455-7.483 (d, 2H; Ar-H), 7.59-7.642 (m, 1H; Ar-H), 7.31 (s, 1H; Ar-H), andD7.927 (s, 2H, Ar-H).
Mass: m/z 459.0 (M+1)
Compound of the Formulae I and II as shown in the accompanied drawings, and their salts are useful in the curative or prophylactic treatment of fungal infections in animals, including humans. For example, they are useful in treating topical fungal infection in man caused by, among other organisms, species of Candida, Trichophyton, Microsporum or Epidermophyton in mucosal infections caused by C. albicans ( eg. thrush and vaginal candidiasis ). They can also be used in the treatment of systemic fungal infections caused by, for example, species of Candida (e. g. Candida albicans ), Cryptococcus neoformans, Aspergillus fumigatus, Fusarium, Rhizopus or Penicillinium marneffei.
The compounds of the present invention have been found to have unexpectedly potent activity against clinically important filamentous species of fungi, besides increased spectrum. The compounds are fungicidal.
The in vitro evaluation of the antifungal activity of the compounds can be performed by determining the minimum inhibitory concentration ( MIC ) as shown in Table 1 which is the concentration of the test compound in Rosewell Park Memorial Institute (RPMI) 1640 liquid medium buffered with 3-(Morpholino)propanesulphonic acid (MOPS) to pH 7, at which there is significant inhibition of the particular fungi. In practice the National Committee for Clinical Laboratory Standard (NCCLS) M27A document for Candida and Cryptococcus and M38P for Aspergillus was used to determine the MIC against yeast and filamentous fungi with suitable modifications for dermatophytes to other filamentous fungi. Three quality control strains were included each time the MIC were determined and readings recorded only when the Quality Control results fell into the acceptable range. After MIC results had been recorded, 100 (j,l from each of the well showing no growth was spread over Sabouraud Dextrose Agar (SDA) to determine the minimum fungicidal concentration (MFC) as shown in Table 2.
The in vivo evaluation of the compound can be carried out at a series of dose levels by oral or I. V. injection to mice which are inoculated I.V. with the minimum lethal dose of Candida albicans, Cryptococcus neoformans or Aspergillus fumigatus by the tail vein. Activity is based on the survival of a treated group of mice after the death of an untreated group of mice. For Aspergillus and Cryptococcus infections, target organs were cultured after treatment to document the number of mice cured of the infection for further assessment of activity.
For human use, the antifungal compounds of the formula and their salts can be administered alone, but will generally be administered in admixture with a pharmaceutical carrier selected with regard to the intended route of administration and standard pharmaceutical practice. For example, they can be administered orally in the form of tablets containing such excipients as starch or lactose, or in capsules or ovules either alone or in admixture with excipients, or in the form of elixirs, solutions or suspensions containing flavouring or colouring agents. They can be injected parenterally, for example, intravenously, intramuscularly or subcutaneously. For parenteral administration, they are best used in the form of a sterile aqueous solution which may contain other substances, for example, enough salts or glucose to make the solution isotonic with blood.
The solubility of a compound of the Formulae I and II in an aqueous medium may be improved by complexation with a hydroxyalkyl derivative of a cyclodextrin in the preparation of an appropriate pharmaceutical composition.
For oral and parenteral administration to human patients, the daily dosage level of the antifungal compounds of the Formulae I and II as shown in the accompanied drawings and their salts will be from 0.01 to 20 mg / kg ( in single or divided doses) when administered by either the oral or parenteral routes. Thus tablets or capsules of the compound will contain from 5 mg to 0.5 gm of active compound for administration singly or two or more at a time, as appropriate. The physician in any event will determine the actual dosage which will be the most suitable for an individual patient and it will vary with age, weight and response of the particular patient. The above dosages are exemplary of the average case, there can, of course, be individual instances, where higher or lower dosage ranges are required and such are within the scope of this invention.
Alternatively, the antifungal compound or Formulae I and II can be administered in the form of a suppository or pessary, or they may be applied topically in the form of a lotion, solution, cream, ointment or dusting powder. For example, they can be incorporated into a cream consisting of an aqueous emulsion of polyethylene glycols or liquid paraffin, or they can be incorporated, at a concentration between 1 and 10 % into an ointment consisting of a white wax or white soft paraffin base together with such stabilizers and preservatives as may be required.
TABLE 1
Minimum Inhibitory Concentration (MIC) (µg/ml) of Standard drugs and compound of this invention against various fungi

(Table Removed)
.Prominent reduction in growth has been taken as MIC endpoint following National Committee for Clinical Laboratory Standard (NCCLS) M27A and M38 P Paecillomyces variotii grows well in 48h
TABLE 2
Minimum Fungicidal Concentration (MFC) (µg/ml) of Standard drugs and compounds, of this invention against QC strains against various filamentous fungi

(Table Removed)

WE CLAIM :
1. A process of preparing a compound of Formula I, as shown in Scheme I of the accompanied drawings and its pharmaceutically acceptable salts, enantiomers, diastereomers, N-oxides prodrugs or metabolites, wherein X is selected from the group consisting of CH2, CO, CS, and SO2;
Ar is a substituted phenyl group having one to three substituents independently selected from a halogen (e.g., fluorine, chlorine, bromine, or iodine), C1-C4 alkyl, halogenated lower (C1-C4) alkyl group and halogenated lower (C1-C4) alkoxy group such as 2,4-difluorophenyl, 2,4-dichlorophenyl, 4-chlorophenyl, 4-fluorophenyl, 2-chlorophenyl, 2-fluorophenyl, 4-trifluoromethylphenyl, 2-fluoro-4-chlorophenyl, 2-chloro-4-fluorophenyl, 4-trifluoromethoxyphenyl, 2,4,6-trifluorophenyl, 4-bromophenyl.
R1 and R2 are each independently selected from the group consisting of hydrogen, C1-C4 alkyl,C1-C4 alkoxy, amino, hydroxy, nitrocyano, carboxyl, protected carboxyl, and SO2 R' wherein R1 is hydrogen, alkyl or aryl;
Y is a phenyl group which is unsubstituted or substituted by 1-3 substituents each independently selected from the group consisting of halogen, nitro.amino, cyano, carboxyl, protected carboxyl, hydroxy, C1-C4 alkyl, C1-C4alkoxy and SO2R' wherein R' is hydrogen, alkyl or aryl;
R3 is selected from the group consisting of hydrogen,C1-C4alkyl group, C1-C4 alkoxy, nitro, amino, cyano, carboxyl, protected caboxyl and SO2R' wherein R1 is hydrogen, alkyl or aryl, and
X1, X2, Y1, Y2 and Z are independently selected from the group consisting of hydrogen halogen, nitro, cyano, amino, sulphonyl, aryl, C1-C4, alkyl, C1-C4alkoxy, halogenated lower (C1-C4) alkyl group, halogenated lower (C1-C4 )alkoxy group and carboxyl, or protected carboxyl.
which comprises reacting the oxo compound of Formula III, as shown in the accompanied drawings, wherein X, Ar, RI, R2, Y, R3, X1, X2, Y1, Y2 and Z have the

same meanings, as defined above, with modified Lawesson's reagent of Formula V, as shown in the accompanied drawings to afford the desired compound of Formula I.
2. A process for preparing a compound of Formula II, as shown in Scheme II of the
accompanied drawings, and its pharmaceutically acceptable salts, enantiomers,
diastereomers, N-oxides, prodrugs or metabolites, wherein
X is selected from the group consisting of CH2, CO, CS, and SO2;
Ar is a substituted phenyl group having one to three substituents independently selected from a halogen (e.g., fluorine chlorine bromine or iodine) C1-C4 alkyl, halogenated lower (C1-C4) alkyl group and halogenated lower (C1-C4) alkoxy group such as 2,4-difluorophenyl, 2,4-dichlorophenyl, 4-chlorophenyl, 4-fluorophenyl, 2-chlorophenyl, 2-fluorophenyl, 4-trifluoromethylphenyl, 2-fluoro-4-chlorophenyl, 2-chloro-4-fluorophenyl, 4-trifluoromethoxyphenyl, 2,4,6-trifluorophenyl, 4-bromopheyl.
RI and R2 are each independently selected from the group consisting of hydrogen, C1-C4 alkyl, C1-C4 alkoxy, amino, hydroxy, nitrocyano, carboxyl, protected carboxyl, and SO2 R' wherein R' is hydrogen, alkyl or aryl; and
X1, X2, Y1, Y2 and Z are independently selected from the group consisting of hydrogen halogen, nitro, cyano, amino, sulphonyl, aryl, C1-C4, alkyl, C1-C4 alkoxy, halogenated lower (C1-C4) alkyl group, halogenated lower (C1-C4 )alkoxy group and carboxyl, or protected carboxyl,
which comprises reacting the oxo compound of Formula IV, as shown in the accompanied drawings, wherein X, Ar, R1, R2, X1, X2, Y1, Y2 and Z are the same as defined above, with modified Lawesson's reagent of Formula V, as shown in the accompanied drawings, to afford the desired compound of Formula II.
3. A process according to claim 1 for preparing the compound namely 2-{[1R2R]-2-
(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazole-1-yl)propyl}-4-{4-[4-(4-
chlorophenyl)-1-piperizinyl]phenyl}-3-(2H,4H)-1,2,4-thiotriazolone

(Compound No. 1).
4. A process according to claim 2 for preparing the compound namely 2-{[1R2R]-2-
(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazole-1-yl)propyl}-1-[4-(4-
methoxyphenyl)-3-(2H,4H)-1,2,4-thiotriazolone (Compound No. 2)
5. A method of treating or preventing a fungal infection in a mammal comprising
administering to said mammal a compound prepared according to any of the
preceding claims.
6. A pharmaceutical composition comprising the compound prepared according to any
of the preceding claims and a pharmaceutical acceptable carrier.
7. A method of treating or preventing a fungal infection in a mammal comprising the
step of administering to said mammal the pharmaceutical composition according to
claim 6.
8. The process for the preparation of the compounds of Formula I, as shown in the
accompanied drawings, substantially as herein described and illustrated by the
examples herein.
9. The process for the preparation of the compounds of Formula II, as shown in the
accompanied drawings substantially as herein described and illustrated by the
examples herein.