in order to achieve the above mentioned aspects and in accordance with the purpose of the invention as embodied and described herein , there are provided processes for the synthesis of compounds of formulae i and ii , wherein x , ar , r 1 , r 2 , r 3 , y , x 1 , x 2 , y 1 , y 2 and z are the same and defined earlier . the starting compounds of formulae iii and iv are known from our published pct application wo 01 / 66551 and u . s . pat . no . 5 , 371 , 101 , respectively and are incorporated herein by reference . in scheme i there is provided a process for preparing a compound of formula i , as shown above and its pharmaceutically acceptable salts , enantiomers , diastereomers , n - oxides , prodrugs , or metabolites , wherein x is selected from the group consisting of ch 2 , co , cs and so 2 ; ar is a substituted phenyl group having one to three substituents independently selected from a halogen ( e . g ., fluorine , chlorine , bromine , or iodine ) c 1 - c 4 alkyl , halogenated lower ( c 1 - c 4 ) alkyl group and halogenated lower ( c 1 - c 4 ) 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 ; r 1 and r 2 are each independently selected from the group consisting of hydrogen , c 1 - c 4 alkyl , c 1 - c 4 alkoxy , amino , hydroxy , nitro , cyano , carboxyl , protected carboxyl , and so 2 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 , c 1 - c 4 alkyl , c 1 - c 4 alkoxy and so 2 r ′ wherein r ′ is hydrogen , alkyl or aryl ; r 3 is selected from the group consisting of hydrogen , c 1 - c 4 alkyl group , c 1 - c 4 alkoxy , nitro , amino , cyano , carboxyl , protected caboxyl and so 2 r ′ wherein r ′ is hydrogen , alkyl or aryl , and x 1 , x 2 , y 1 , y 2 and z are independently selected from the group consisting of hydrogen , halogen , nitro , cyano , amino , sulphonyl , aryl , c 1 - c 4 alkyl , c 1 - c 4 alkoxy , halogenated lower ( c 1 - c 4 ) alkyl group , halogenated lower ( c 1 - c 4 ) alkoxy group and carboxyl , or protected carboxyl . when r 1 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 , wherein x , ar , r 1 , r 2 , y , r 3 , x 1 , x 2 , y 1 , y 2 and z have the same meanings as defined above , with modified lawesson &# 39 ; s reagent of formula v , 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 published pct application wo 01 / 66551 . the modified lawesson &# 39 ; s reagent is prepared according to the procedure as disclosed by masataka yokohamna et al . in synthesis , pp 827 - 829 ( 1984 ). in scheme ii there is provided a process for preparing a compound of formula ii , as shown above and its pharmaceutically acceptable salts , enantiomers , diastereomers n - oxides , prodrugs or metabolities , wherein x is selected from the group consisting of ch 2 , co , cs and so 2 ; ar is a substituted phenyl group having one to three substituents independently selected from a halogen ( e . g ., fluorine , chlorine , bromine , or iodine ), c 1 - c 4 alkyl , halogenated lower ( c 1 - c 4 ) alkyl group and halogenated lower ( c 1 - c 4 ) 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 ; r 1 and r 2 are each independently selected from the group consisting of hydrogen , c 1 - c 4 alkyl , c 1 - c 4 alkoxy , amino , hydroxy , nitro , cyano , carboxyl , protected carboxyl , and so 2 r ′ wherein r ′ is hydrogen , alkyl or aryl ; and x 1 , x 2 , y 1 , y 2 and z are independently selected from the group consisting of hydrogen , halogen , nitro , cyano , amino , sulphonyl , aryl , c 1 - c 4 , alkyl , c 1 - c 4 alkoxy , halogenated lower ( c 1 - c 4 ) alkyl group , halogenated lower ( c 1 - c 4 ) alkoxy group and carboxyl , or protected carboxyl . when r 1 is other than hydrogen , formula ii 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 ; which comprises reacting the oxo compound of formula iv , wherein x , ar , r 1 , r 2 , x 1 , x 2 , y 1 , y 2 and z have the same meanings as defined above , with modified lawesson &# 39 ; s reagents [ prepared according to the procedure as disclosed by masataka yokohama et al in synthesis , pp 827 - 829 ( 1984 )] of formula v , to afford the desired compound of formula ii . the starting compound of formula iv is prepared by following the procedure as disclosed in the u . s . pat . no . 5 , 371 , 101 . in the above schemes where specific solvent and specific modified lawesson &# 39 ; s reagent are mentioned , it is to be understood that other solvents and lawesson &# 39 ; s reagent or modification thereof may be used . similarly , the reaction temperature and duration of the reaction may be adjusted according to the need . an illustrative list of some of the compounds according to the invention and capable of being produced by schemes i and ii include : the examples mentioned below demonstrate the general synthetic procedure as well as specific preparation for the preferred compound . the examples are given to illustrate the details of the invention and should not be constrained 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 . a mixture of the appropriate oxo compound ( 1 . 15 mmol ) and modified lawesson &# 39 ; 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 vacuo . the residue thus obtained was washed several times with dichloromethane . the dichloromethane soluble fractions were combined and concentrated in vacuo . 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 ). the oxo compound ( 1 mol ) and lawesson &# 39 ; s reagent ( 2 mol equivalent .) were dried under high vacuum for 10 min , 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 . a mixture of 2 -{[ 1r , 2r ]- 2 -( 2 , 4 - difluorophenyl )- 2 - hydroxy - 1 - methyl - 3 -( 1h - 1 , 2 , 4 - triazol - 1 - yl ) propyl }- 4 -( 2 ′, 2 ′, 3 ′, 3 ′- tetrafluoropropoxyphenyl )- 3 -( 2h , 4h )- 1 , 2 , 4 - thiotriazolone ( 1 . 41 g ) and lawesson &# 39 ; s reagent ( 2 . 08 g , 2 . 0 m eq ) was heated to reflux in toluene for 3 - 15 hr . reaction mixture was concentrated under vacuum to give yellow semi - solid which was stirred with dichloromethane for 10 min . the solid was filtered and washed with dichloromethane . the combined filtrate and washings were concentrated under vacuum to give yellow semi - solid which was purified using column chromatography ( first using silica gel , 60 - 120 mesh and then active alumina , basic ) to give white fluffy solid as a desired compound ( 0 . 3 g ). assignment of rriss was done on the basis of 1 hnmr analysis . an illustrative list of some of the compounds of the invention which were synthesised by one or more of the above described methods is given below alongwith their 1 hnmr data . all 1 hnmr spectra were recorded on brucker amx 300 nmr machines ( 300 mhz ) using cdci 3 as a solvent and tms 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 : quartet ; dd : double doublet ; m : multiplet ; br : broad ; j : coupling constant : m . p . : 129 - 130 ° c . ir ( kbr ): 3421 , 2916 , 2847 , 1614 , 1595 cm − 1 nmr ( cdcl 3 ): δ1 . 33 ( d , j = 6 . 7hz , ch — ch 3 ), 3 . 33 - 3 . 42 ( m , 8h , piperazine - h ), 4 . 35 ( d , j = 14 . 3hz , 1h , ch 2 - triazole ), 5 . 14 ( d , j = 14 . 4hz , ch 2 - triazole ), 5 . 19 ( bs , 1h , — oh ), 5 . 93 ( q , j = 6 . 7hz , 1h , ch — ch 3 ), 6 . 81 - 6 . 90 ( m , 4h , ar — h ), 7 . 05 ( d , j = 8 . 6hz , 2h , ar — h ), 7 . 24 ( d , j = 8 . 5hz , 2h , ar — h ), 7 . 43 ( d , j = 8 . 5hz , 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 ) m . p . : 166 - 170 ° c . ir ( kbr ): 3436 , 2924 , 1615 , 1511 , 1476 , 1258 , 962 and 835 cm − 1 nmr ( cdcl 3 ): δ1 . 36 ( d , 1h , j = 9hz ; ch — ch 3 ), 3 . 873 ( s , 3h ; och 3 ), 4 . 351 ( d , 1h , j = 14 . 4hz ; triazole - ch 2 ), 5 . 703 - 5 . 202 ( m , 2h ; triazole - ch 2 & amp ; oh ), 5 . 933 ( q , 1h , j = 6 . 9hz , ch — ch 3 ), 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 ), and 7 . 927 ( s , 2h , ar — h ). mass : m / z 459 . 0 ( m + 1 ) m . p . : 76 . 8 - 84 . 3 ° c . ir ( kbr ): 3447 , 1618 , 1515 , 1423 , 1135 , 1110 and 867 . 6 cm − 1 nmr ( cdcl 3 ): δ1 . 33 ( d , 3h , j = 9hz ; ch — ch 3 ), 4 . 41 ( m , 3h ; och 2 cf 2 and triazole - ch 2 ), 5 . 16 ( d , 1h , j = 14 . 4hz ; triazole - ch 2 ), 5 . 92 ( q , 1h , j = 9hz ; ch — ch 3 ), 6 . 07 ( tt , 1h , j = 53 . 4 and 4 . 5hz ; cf 2 cf 2 h ), 6 . 85 ( m , 2h ; ar — h ), 7 . 11 ( d , 2h ; j = 9 . 0hz ; ar — h ), 7 . 58 ( m , 3h ; ar — h ), 7 . 77 ( s , 1h ), 7 . 96 ( s , 1h ), and 8 . 26 ( s , 1h ). mass : m / z 559 ( m + 1 ) compounds of the formulae i and ii as shown herein , 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 mameffei . 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 μl 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 1 . 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 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 of 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 . [ 0085 ] table 2 minimum fungicidal concentration ( meg ) ( μg / ml ) of standard drugs and compounds of this invention against qc strains against various filamentous fungi compound no . 1 ( this fluconazole amphotericin - b itraconazole invention ) tak 187 1 . c krusei 6258 128 1 64 0 . 016 64 2 . c parapsilosis 22019 4 32 8 0 . 016 0 . 03 3 . p variotii 22319 & gt ; 128 2 0 . 06 0 . 06 32 4 . a fumigatus si - 1 - 1019 & gt ; 128 2 0 . 25 0 . 03 32 5 . a fumigatus 1008 & gt ; 128 1 0 . 06 0 . 03 8 6 . a flavus p2 - 1045 & gt ; 128 1 0 . 25 0 . 03 32 7 . a flavus p3 - 1041 & gt ; 128 0 . 5 0 . 06 0 . 06 — 8 . a flavus e3 - 1044 & gt ; 128 0 . 5 0 . 03 0 . 03 8 9 . a flavus e4 - 1042 & gt ; 128 0 . 125 0 . 125 0 . 03 — 10 . a niger e5 - 1047 & gt ; 128 0 . 25 0 . 125 0 . 06 2 11 . a niger p1 - 1046 & gt ; 128 0 . 25 0 . 25 0 . 06 0 . 5 12 . penicillium h - 1048 & gt ; 128 2 & gt ; 128 4 & gt ; 128 13 . penicillium i - 1049 & gt ; 128 4 & gt ; 128 1 128 14 . penicillium 1641 & gt ; 128 16 0 . 06 0 . 25 32 15 . penicillium 2548 & gt ; 128 4 0 . 06 0 . 125 16 16 . penicillium 31620 & gt ; 128 0 . 25 1 0 . 125 16 17 . penicillium 191 & gt ; 128 2 0 . 06 0 . 125 16 18 . penicillium 2306 & gt ; 128 0 . 5 16 0 . 06 16 19 . rhizopus 1052 & gt ; 128 8 8 0 . 03 32 20 . rhizopus ( ceylon ) & gt ; 128 64 128 0 . 5 & gt ; 128 21 . alternaria 1051 & gt ; 128 & gt ; 128 32 0 . 06 16 22 . fusarium ( ceylon ) & gt ; 128 & gt ; 128 & gt ; 128 32 128 23 . fusarium 29600 & gt ; 128 & gt ; 128 & gt ; 128 & gt ; 128 & gt ; 128 24 . fusarium 18270 & gt ; 128 & gt ; 128 128 & gt ; 128 32 25 . mucor ( ceylon ) & gt ; 128 1 & gt ; 128 1 & gt ; 128 a comparative in vitro and in vivo biologically activity data of the compound of our invention , 2 -{[ 1r , 2r ]- 2 -( 2 , 4 - difluorophenyl )- 2 - hydroxy - 1 - methyl - 3 -( 1h - 1 , 2 , 4 - triazole - 1 - yl ) propyl }- 4 -[( 2 ′, 2 ′, 3 ′, 3 ′- tetrafluoropropoxyphenyl )- 3 -( 2h , 4h )- 1 , 2 , 4 - thiotriazolone ( compound no . 3 ) with 2 -[( 1 r , 2r )- 2 -( 2 , 4 - difluorophenyl )- 2 - hydroxy - 1 - methyl - 3 -( 1h - 1 , 2 , 4 - triazol - 1 - yl ) propyl ]- 4 -( 2 ′, 2 ′, 3 ′, 3 ′- tetraflouropropoxyphenyl )- 3 ( 2h , 4h )- 1 , 2 , 4 - triazolone ( tak 187 ) and standard antifungal pharmaceuticals is given below : mic 50 mic 90 g . m . all fungal pathogens mic ( μg / ml ) amphotericin b 0 . 25 0 . 5 0 . 21 fluconazole 256 256 105 itraconazole 0 . 19 256 0 . 437 tak 187 8 32 4 . 16 compound no . 3 0 . 25 2 0 . 285 all candida isolates mic ( μg / ml ) amphotericin b 0 . 25 0 . 25 0 . 22 fluconazole 8 128 5 . 3 itraconazole 0 . 25 0 . 5 0 . 1 tak 187 0 . 5 2 0 . 45 compound no . 3 0 . 5 1 0 . 1 all filamentous isolates mic ( μg / ml ) amphotericin b 0 . 25 0 . 5 0 . 22 fluconazole 256 256 199 itraconazole 0 . 25 256 0 . 6 tak 187 8 32 7 . 246 compound no . 3 0 . 25 8 0 . 328 aspergillus fumigatus isolates mic ( μg / ml ) amphotericin b 0 . 25 0 . 5 0 . 27 fluconazole 256 256 256 itraconazole 0 . 25 0 . 5 0 . 181 tak 187 8 8 7 . 4 compound no . 3 0 . 125 0 . 25 0 . 112 rhizoupus spp . isolates mic ( μg / ml ) amphotericin b 0 . 125 0 . 25 0 . 177 fluconazole 256 256 256 itraconazole 16 64 32 tak 187 4 4 4 compound no . 3 0 . 125 0 . 125 0 . 125 fusarium spp . isolates mic ( μg / ml ) amphotericin b 0 . 5 2 0 . 841 fluconazole 256 256 256 itraconazole 64 256 90 . 51 tak 187 32 64 45 . 255 compound no . 3 8 8 8 penicillium spp . isolates mic ( μg / ml ) amphotericin b 0 . 25 0 . 25 0 . 144 fluconazole 256 256 174 . 181 itraconazole 0 . 5 256 0 . 922 tak 187 16 64 18 . 664 compound no . 3 2 8 1 . 516 activity against dermatophytes compound organism fluconazole itraconazole terbina no . 3 t . mentagrophyte & gt ; 128 0 . 125 0 . 002 0 . 016 t . rubrum & gt ; 128 0 . 03 0 . 016 0 . 004 in vivo anti - fungal activity of compound no . 3 ; determination of 50 % effective dose ( ed 50 ): briefly , swiss albino mice weighing 20 ± 2 g were injected intravenously ( tail vein ) with sufficient fungal cells to kill 100 % of the untreated animals for aspergillus fumigatous strain used . in all cases each group comprised of six mice . five does levels , utilizing doubling dilution range , were employed per determination ranging from 25 to 1 . 56 mg / kg bw . dosing was carried out for five days starting after 30 minutes of infection . a mortality rate of 100 % was observed in all groups of untreated mice . treated animals were monitored twice daily for 14 days post infection at which time the experiment was terminated and ed 50 was calculated . ed5o in mg / kg body weight drug day 7 post infection day 14 post infection compound no . 3 2 . 33 6 . 25 itraconazole 8 . 84 21 . 02 tak 187 10 . 08 20 . 39 infection control — — while the present invention has been described in terms of its specific embodiments , certain modifications and equivalents will be apparent to those skilled in the art and are intended to be included within the scope of the present invention .