text: most starting materials are commercially available ( e . g . from acros , aldrich , fluka ). commercially not available ketones ( 1 ) can be obtained via grignard reaction of the corresponding nitrites through procedures well known in the art . the α - halo - ketones ( 2 ) can be synthesized by bromination of ketones ( 1 ) with bromine in dichloromethane . using diazotation followed by reduction , hydrazines ( 4 ) can be obtained from the corresponding primary amines . the synthetic strategies are shown in scheme 1 of fig1 . the compounds of formula ( i ) with r 2 ═ sh , can be prepared by first reacting a α - haloketone ( 2 ) with an alkali thiocyanate such as potassium thiocyanate to obtain a thiocyanatoketone ( 3 ); the obtained thiocyanatoketone can be further reacted with a hydrazine derivative ( 4 ) into the hydrazone , which spontaneously will rearrange into the 1 - amino - 2 - imidazolethione derivative ( 9 ) ( compounds of formula ( i ) with r 2 ═ sh ). the corresponding synthetic strategies are shown in scheme 2 of fig2 . compounds of formula ( i ) with r 2 ═ h , can be obtained by desulfurizing the former obtained 1 - amino - 2 - imidazolethione derivatives with e . g . hydrogen peroxide to obtain the 1 - amino - imidazole derivatives of formula ( i ) with r 2 ═ h ( 13 ). the corresponding synthetic strategy is shown in scheme 3 of fig3 . alternatively , the compounds of formula ( i ) with r 2 ═ sh ( 9 ) can be obtained in a one pot procedure as outlined below . hereto , the α - halo - ketone ( 2 ) and alkali thiocyanate such as potassium thiocyanate can be first reacted in acetic acid , after which the monosubstituted hydrazine ( 4 ) is added to the resulting mixture at ambient temperature . for some combinations of reactants mild heating can be required to obtain the 1 - amino - 2 - imidazolethione derivative ( 9 ) which can be isolated using standard procedures . the corresponding synthetic strategy is shown in scheme 2 of fig2 . examples of compounds of formula ( i ) with r 2 ═ sh obtained by this method are shown in table 1 . both alternatives may be summarized as a process for preparing a compound of formula ( i ), a pharmaceutically acceptable salt , a tautomer , an isomer , an ester or a glycosylation product thereof , comprising the steps of reacting an α - haloketone having the formula q -( ch 2 ) n — co — chr 1 x , wherein q , r 1 and n are as defined in formula ( i ) and x is a halogen atom , first with an alkali thiocyanate and then with a hydrazine derivative having the formula l -( ch 2 ) m — nhnh 2 , thereby obtaining an n - aminoimidazolethione derivative having the formula ( i ) wherein r 2 is — sh . prior research has been done to gain insight into the mechanism of this reaction . as already reported [ j . g . schantl , i . m . lagoja , heterocycles , 1997 , 45 , 691 . ], this multistep reaction is considered to follow the path outlined in scheme 2 of fig2 . in a first step the α - halo - ketone ( 2 ) is reacted with an alkali thiocyanate such as potassium thiocyanate to obtain the thiocyanatoketone ( 3 ), which is converted by reaction with hydrazine ( 4 ) into the hydrazone ( 5 ). this hydrazone ( 5 ) easily can undergo a 1 , 4 - elimination forming the corresponding azoalkene [ j . g . schantl , m . prean , monatsh . chem . 1993 , 124 , 299 . ] ( 6 ) and thiocyanic acid . these intermediates subsequently undergo a [ 3 + 2 ] cycloaddition reaction [ j . g . schantl , h . p . kählig , m . prean , heterocycles , 1994 , 37 , 1873 . ]. the azo - alkene ( 6 ) is serving as an isoelectronic hetero - allyl anion equivalent whereas the thiocyanic acid reacts as dipolarophile . the resulting heterocyclic azomethine imine intermediate ( 7 ) is anticipated to equilibrate with the zwitterion ( 8 ) by a proton transfer from the thiourea nh to the more basic exocyclic nitrogen atom . the 1 - amino - 2 , 3 - dihydro - 1h - imidazole - 2 - thione ( 9 ) is provided from a final 1 , 2 - hydrogen shift from 4 - c to 3 - n . the 1 - amino - 1h - imidazole derivatives ( 13 ) or compounds of formula ( i ) with r 2 ═ h can be obtained with an oxidative reduction of the substituted 1 - amino - 2 , 3 - dihydro - 1h - imidazole - 2 - thiones ( 9 ) as shown in scheme 3 of fig3 . examples of the imidazoles ( 13 ) derived by this method are reported in table 2 . desulfurization of thioureas has been achieved in the past by using raney nickel [ c . temple , j . med . chem . 1990 , 33 , 656 . ], nitric acid [ j . davoll , j . chem . soc . 1958 , 1593 . ], singlet oxygen [ w . m . abdou , m . m . sidky , h . wamhoff , z . naturforsch ., b . 1987 , 42 , 1153 . ], ozone [ c . crestini , e . mincione , r . saladino , r . nicoletti , tetrahedron , 1994 , 50 , 3259 . ], ferric chloride [ m . m . fraser , r . a . raphael , j . chem . soc . 1952 , 226 . ] or hydrogen peroxide [ a ) h . - j . schönherr , h . - w . wanzlick , chem . ber , 1970 , 103 , 1037 ; b ) d . w . karkhanis , l . field , phosphorus sulfur , 1985 , 22 , 49 ; c ) s . grivas , e . ronne , acta chem . scand . 1995 , 49 , 225 ; d ) j . g . schantl , i . m . lagoja , heterocycles , 1998 , 48 , 929 .]. a suitable procedure consists of treating a compound of formula ( i ) wherein r 2 ═ sh ( 9 ) with 30 % hydrogen peroxide at 10 ° c ., selectively cleaving off the sulfur atom of the 2 - thione function . as reported in prior art , hereby at first oxidation of the sulfur atom can take place ( scheme 3 , fig3 ). upon loss of so n from the sulfonic acid intermediate ( 10 ) or possibly from the zwitterionic isomer ( 11 ), the resultant carbene - type intermediate ( 12 ) can undergo a proton shift to yield the 1 - amino - 1h - imidazole derivative ( 13 ). alkylation of 1 - amino - 2 - imidazolethione derivative compounds 9 by means of an alkylating agent having the formula r 0 x , wherein r 0 is e . g . methyl or benzyl , can quantitatively yield the s - alkyl derivatives ( 14 ). the reaction is shown in scheme 4 of fig4 . under mitsunobu conditions [ d . l . comins , g . jianhua , tetrahedron lett . 1994 , 35 , 2819 – 2822 . ] the s - alkyl - derivatives can also be obtained . only in case of glycosylation by means of a glycosylating agent under verbrueggen conditions , a temperature dependent s - or n - glycoslyation product can be formed [ i . m . lagoja , a . van aerschot , c . hendrix , p . herdewijn , collect . czech . chem . commun . 2000 , 65 , 1145 – 1155 ]. the following examples are provided for the purpose of illustrating the present invention and should in no way be interpreted as limiting the scope thereof . nmr spectra were recorded on a varian , gemini 200 spectrometer ( 1 h - 200 mhz , 13 c 50 mhz ). all nh protons were assigned by exchange with d 2 o . in case of aa ′ bb ′ systems determination of j is based on the assumption of an ab quartett [ e . d . becker in : “ high resolution nmr , theory and chemical application ”, academic press , new york , 1969 , 169 . ] exact mass measurements were performed on a quadrupole — time of flight mass spectrometer ( q - tof - 2 , micromass , manchester , uk ) equipped with a standard electrospray ionization ( esi ) interface . samples were infused in a 2 - propanol : water ( 1 : 1 ) mixture at 3 ml / min . tlc was performed with tlc aluminum sheets ( merck , silica gel 60 f 254 ) and silica ( 200 – 425 mesh ) was used for column chromatography . melting points ( mp [° c .]) were determined with a kofler - bank . all starting materials are commercially available ( e . g . from acros , aldrich , fluka ) or can be obtained as outlined further . b . 1 . synthesis of ketones ( 1 ) from nitriles via grignard reaction : general procedure in a 2 - neck flask equipped with a reflux condenser and a dropping funnel a suspension of magnesium ( 2 . 83 g , 0 . 12 mol ) and alkylbromide ( 0 . 12 mol ) in dry ether were stirred under nitrogen . after addition of a crystal of iodine the reaction started . after the reaction was completed a solution of the nitrile ( 0 . 1 mol ) in dry ether ( 15 ml ) was added dropwise . following heating under reflux for 6 hours the mixture was quenched with 6n h 2 so 4 ice ( 100 ml ). to complete the hydrolysis of the ketimine the mixture was warmed and afterwards extracted with ether . after removing the solvent the resulting ketones could be used without further purification . [ evans , gordon , j . chem . soc . 1938 , 1434 , 1438 . ] yield : quant ; 1 h - nmr ( cdcl 3 ): 0 . 97 , 1 . 00 ( 6h , 2 × s , 2 × ch 3 ), 2 . 29 ( 1 h , m , ch ), 2 . 80 ( 2h , d , j = 6 . 6 hz , ch 2 ), 7 . 43 – 7 . 63 ( 3h , m , 3 , 4 , 5h ar ), 7 . 93 ( 2h , ( d ), 2 , 6h ar ). [ h . gilman , j . eitsch , j . am . chem . soc . 1957 , 79 , 2150 – 2153 . ] yield : quant ; 1 h - nmr : 0 . 98 ( 3h , t , j = 7 . 4 hz , ch 3 ), 1 . 74 ( 2h , t × q , j = 7 . 4 hz , ch 2 ), 2 . 91 ( 2h , t , j = 7 . 4 hz , ch 2 co ), 7 . 37 – 7 . 58 ( 3h , m , 3 , 4 , 5h ar ), 7 . 92 ( 2h , ( d ), 2 , 6h ar ). yield : quant ; 1 h - nmr : 1 . 89 ( 3h , t , j = 7 hz , ch 3 ), 2 . 89 ( 2h , q , j = 7 hz , ch 2 ), 7 . 09 ( 1h , m , 4 - h ), 7 . 53 – 7 . 70 ( 2h , m , 3 , 5 - h ). based on kulkarni , n . r . ayyangar , tetrahedron , 1994 , 50 , 1243 – 1260 . ]: a mixture of 3 - bromopropiophenone ( 10 . 65 g , 50 mmol ), cucn ( 5 . 82 g , 65 mmol ) in dmf ( 35 ml ) was heated under reflux for 6 h . after cooling the mixture to ambient temperature fecl 3 ( 5 g ) in h 2 o ( 30 ml )/ hcl conc ( 10 ml ) was added and heated to 80 ° c . for another 20 min . after cooling to room temperature and extraction with ether further purification occurred by destination under reduced pressure ( bp . : 140 ° c ., 10 torr ). the ketone could be obtained as slightly yellow , low melting ( 42 ° c .) solid . yield : 81 %, 1 h - nmr ( cdcl 3 ): 1 . 29 ( 3h , t , j = 7 . 2 hz , ch 3 ), 3 . 11 ( 2h , q , j = 7 . 2 hz , ch 2 ), 7 . 69 ( 1h , ( t ), j ˜ 8 hz , 5 - h ar ), 7 . 90 ( 1h , d , j = 7 . 6 hz , 4 - h ar ), 8 . 24 ( 1h , d , j = 8 . 2 hz , 6 - h ar ), 8 . 29 ( 1h , s , 2 - h ar ). after refluxing 3 - cyanopropiophenone 1 . 06 ( 3 . 5 g ) with koh ( 2 . 5 g ) in ethanol ( 30 ml ) for 2 hours the nitrile could be hydrolyzed to the corresponding acid derivative . following removal of the solvent , dilution of the alkaline residue with water and acidification , the acid could be isolated , which was converted into the ester 1 . 07 by treatment with methanol ( 20 ml ) and h 2 so 4 conc . ( 1 ml ). after removing the solvent the residue was diluted with water and extracted with ethyl acetate . after drying the organic layer over na 2 so 4 and removing the solvent the 3 - methoxycarbonylpropiophenone 1 . 07 could be isolated in 85 % yield over 2 steps . yield : 85 %, 1 h - nmr ( cdcl 3 ): 1 . 23 ( 3h , t , j = 7 . 2 hz , ch 3 ), 3 . 06 ( 2h , q , j = 7 . 2 hz , ch 2 ), 3 . 95 ( 3h , s , ch 3 o ), 7 . 58 ( 1h , ( t ), j ˜ 8 hz , 5 - h ar ), 8 . 20 – 8 . 27 ( 2h , m , 4 , 6 - h ar ), 8 . 60 ( 1h , s , 2 - h ar ). to an ice - cooled solution of the corresponding ketone 1 ( 0 . 04 mol ), bromine ( 0 . 04 mol , 2 ml ) was added dropwise . the almost colorless solution was stirred at room temperature for another 20 min . after addition of aqueous nahco 3 - solution ( 100 ml ) the organic layer was separated and dried over na 2 so 4 . following removal of the solvent the ketones could be used without further purification . in case of 3 - cyanopropiophenone 1 . 06 in contrast the reaction needed to be heated under reflux . [ n . de kimpe , r . verhe , l . de buyck , n . schamp , j . org . chem . 1980 , 45 , 2803 – 2813 . 1 ] yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 90 ( 3h , d , j = 6 . 6 hz , ch 3 ), 5 . 31 ( 1h , d , j = 6 . 6 hz , ch ), 7 . 42 – 7 . 58 ( 3h , m , 3 , 4 , 5 h ar ), 8 . 00 ( 2h , ( d ), 2 , 6 h ar ). [ n . de kimpe , r . verhe , l . de buyck , n . schamp , tetrahedron lett ., 1980 , 21 , 2257 – 2260 . ] _yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 90 ( 3h , d , j = 6 . 6 hz , ch 3 ), 5 . 24 ( 1h , q , j = 6 . 6 hz , ch ), 7 . 34 ( 1h , ( t ), j ˜ 7 . 8 hz , 5 - h ar ), 7 . 69 ( 1h , d , j = 7 . 6 hz , 4 - h ar ), 7 . 92 ( 1h , d , j = 7 . 8 hz , 6 - h ar ), 8 . 12 ( 1h , s , 2 - h ar ). [ k . l . nelson j . c . robertson , j . j . duvall j . am . chem . soc . 1964 , 86 , 684 – 687 . ] yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 90 ( 3h , d , j = 6 . 6 hz , ch 3 ), 5 . 24 ( 1h , q , j = 6 . 6 hz , ch ), 7 . 55 , 7 . 60 ( 2h , 2 , 6h ar )- 7 . 83 , 7 . 87 ( 2h , 3 , 5h ar , aa ′ bb ′ j ˜ 8 . 2 hz ). [ l . szotyory , e . hamburg , j . prakt . chem . 1963 , 22 , 202 – 213 . ] yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 89 ( 3h , d , j = 6 . 6 hz , ch 3 ), 5 . 25 ( 1h , q , j = 6 . 6 hz , ch ), 7 . 41 ( 1h , ( t ), j ˜ 7 . 8 hz , 5 - h ar ), 7 . 55 ( 1h , d , j = 7 . 6 hz , 4 - h ar ), 7 . 89 ( 1h , d , j = 7 . 8 hz , 6 - h ar ), 7 . 96 ( 1h , s , 2 - h ar ). [ b . l . chenard , j . bordner , t . w . butler , l . k . chambers , m . a . collins , j . med . chem . 1995 , 38 , 3138 – 3145 . ] yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 91 ( 3h , d , j = 6 . 6 hz , ch 3 ), 5 . 25 ( 1h , q , j = 6 . 6 hz , ch ), 7 . 43 , 7 . 48 ( 2h , 2 , 6h ar )- 7 . 94 , 7 . 99 ( 2h , 3 , 5h ar , aa ′ bb ′ j ˜ 8 . 4 hz ). [ c . w . perry m . v . kalnins , k . h . deitcher j . org . chem . 1972 , 37 , 4371 – 4376 . ] yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 88 ( 3h , d , j = 6 . 6 hz , ch 3 ), 3 . 84 ( 3h , s , ch 3 o ), 5 . 27 ( 1h , q , j = 6 . 6 hz , ch ), 6 . 90 , 6 . 95 ( 2h , 2 , 6h ar )- 7 . 96 , 8 . 01 ( 2h , 3 , 5h ar , aa ′ bb ′ j ˜ 8 . 2 hz ). [ a . v . wacek , k . kratzl , a . v . bezard , chem . ber . 1942 , 75 , 1348 , 1352 . ] yield : quant ; 1 h - nmr ( cdcl 3 ): 2 . 27 ( 3h , s , ch 3 ), 5 . 44 ( 1h , s , ch ), 7 . 33 – 7 . 46 ( 5h , m , ar ). [ n . de kimpe , r . verhe , l . de buyck , n . schamp , tetrahedron lett ., 1980 , 21 , 2257 – 2260 . ] yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 08 ( 3h , t , j = 7 . 4 hz , ch 3 ), 2 . 18 ( 2h , q × d , j 1 = 6 . 6 hz , j 2 = 7 . 4 hz ch 2 ), 5 . 08 ( 1h , t , j = 6 . 6 hz ), 7 . 47 – 7 . 62 ( 3h , m , 3 , 4 , 5h ar ), 8 . 02 ( 2h , ( d ), 2 , 6 h ar ). [ e . g . boswell , d . l . musso , j . l . kelley , f . e . soroko , b . r . cooper , j . heterocycl . chem . 1996 , 33 , 33 – 40 . ] yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 05 , 1 . 23 ( 6 h , 2 × d , j = 6 . 6 hz , 2 × ch 3 ), 2 . 47 ( 1h , m , ch ), 5 . 01 ( 1h , d , j = 8 . 4 hz , chc ═ o ), 7 . 41 – 7 . 66 ( 5h , m , ar ). [ e . bienvenue - goetz , j . - e . dubois , j . am . chem . soc . 1981 , 103 , 5388 – 5392 . ] _yield : quant ; 1 h - nmr ( cdcl 3 ): 2 . 36 ( 3h , s , ch 3 ), 3 . 75 ( 3h , s , ch 3 o ), 4 . 77 ( 1h , s , ch ). [ w . s . lee , k . d . nam , h . - g . hahn , h . d . mah , j . heterocycl . chem ., 1993 , 30 , 1105 , 1110 . ] yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 78 ( 3h , d , j = 6 . 6 hz , ch 3 ), 3 . 88 ( 3h , s , ch 3 o ), 5 . 15 ( 1h , q , j = 6 . 6 hz [ l . villa et . al . farmaco ed . sci . 1974 , 29 , 73 – 79 . ] yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 94 ( 3h , d , j = 6 . 4 hz , ch 3 ), 5 . 30 ( 1h , q , j = 6 . 4 hz , ch ), 7 . 66 ( 1h , ( t ), j ˜ 7 . 8 hz , 5 - h ar ), 7 . 90 ( 1h , d , j = 6 . 6 hz , 4 - h ar ), 8 . 25 ( 1h , d , j = 8 hz , 6 - h ar ), 8 . 31 ( 1h , s , 2 - h ar ). yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 94 ( 3h , d , j = 6 . 6 hz , ch 3 ), 3 . 96 ( 3h , s , ch 3 o ), 5 . 31 ( 2h , q , j = 6 . 6 hz , ch 2 ), 7 . 62 ( 1h , ( t ), j ˜ 8 hz , 5 - h ar ), 8 . 20 – 8 . 28 ( 2h , m , 4 , 6 - h ar ), 8 . 66 ( 1h , s , 2 - h ar ). yield : quant ; 1 h - nmr ( cdcl 3 ): 1 . 86 ( 2h , d , j = 6 . 4 hz , ch 3 ), 5 . 18 ( 1h , q , j = 6 . 4 hz , ch ), 7 . 12 ( 1h , t , j = 6 hz , 4 - h ), 7 . 69 ( 1h , d , j = 6 hz , 3 - h ), 7 . 81 ( 1h , d , j = 6 hz , 5 - h ). a suspension of the corresponding aniline ( 0 . 082 mol ) was cooled to − 10 ° c . a solution of nano 2 ( 5 . 7 g , 0 . 09 mol ) in water ( 10 ml ) was slowly added keeping the temperature always beyond − 5 ° c . the red solution formed was stirred at − 10 ° c . for another 30 min , after which a solution of sncl 2 ( 47 g , 0 . 25 mol ) in hcl conc . ( 50 ml ) was slowly added . a white precipitate was immediately formed . after the addition was completed the mixture was stored at 4 ° c . overnight and following filtration and washing with hexane the precipitate was suspended in 10 % naoh ( 200 ml ). after extraction with ether , drying over na 2 so 4 and removing the solvent , the obtained hydrazine could be used without further purification . [ borsche , groth , just . lieb . ann . chem . 1941 , 238 – 247 . ] yield : 72 %; 1 h - nmr ( dmso - d 6 ): 2 . 17 ( 6h , s , 2 ch 3 ), 3 . 90 ( 2h , s , br ex , nh 2 ), 6 . 25 ( 1h , s , 4 - h ar ), 6 . 42 ( 2h , s , 2 , 6 - h ar ), 6 . 65 ( 1h , s , br , ex , nh ). [ kermack , perkin , robinson , j . chem . soc . 1921 , 119 , 1641 . ] yield : 74 %; 3 . 67 ( 3h , s , ch 3 o ),), 3 . 90 ( 2h , s , br ex , nh 2 ), 6 . 13 ( 1h , d , j = 8 hz , 6 - h ar ), 6 . 32 – 6 . 40 ( 2h , m , 2 - h ar , 4 - h ar ), 6 . 63 ( 1h , s , br ex , nh ), 6 . 97 ( 1h , ( t ), j = 8 hz , 5 - h ar ). [ j . g . schantl , i . m . lagoja , heterocycles , 1997 , 45 , 691 . ]: to a stirred solution of the α - halo ketone 2 ( 2 . 5 mmol ) in acetic acid ( 10 ml ) potassium thiocyanate ( 0 . 37 g , 3 . 8 mmol ) was added at ambient temperature . after 30 min the hydrazine 4 ( 2 . 5 mmol ) or hydrazine hydrochloride was added . following stirring for 4 h at room temperature the reaction mixture was evaluated with tlc ( ch 2 cl 2 : meoh = 99 : 1 ). in case no product formation could be observed , the mixture was warmed to 80 ° c . for 2 h . after adding 30 ml of water the precipitate was filtered off and washed with water . mostly recrystallization from methanol afforded pure products , only in some cases further purification by column chromatography ( silica , ch 2 cl 2 : meoh = 99 : 1 ) was necessary . a mixture of benzoine ( 1 . 0 g , 0 . 0071 mol ), kscn ( 0 . 68 g , 0 . 0071 mol ) and 3 - chlorophenylhydrazine × hcl ( 1 . 26 g , 0 . 0071 mol ) was stirred in acetic acid ( 10 ml ) for two days . the white precipitate formed was filtered off ( 0 . 4 g ). water ( 50 ml ) was added and the precipitate formed was filtered off . recrystallization from meoh / water ( 1 : 1 ) yielded 1 . 5 g ( 56 %) of 9 . 26 . the corresponding methoxycarbonyl substituted imidadazoline - 2 - thione derivative ( 1 . 33 mmol ) ( 9 . 27 , 9 . 34 , 9 . 35 , respectively ) was stirred in a 10 % solution of naoh ( 25 ml ) for 6 h . after washing with ch 2 cl 2 removing impurities , the aqueous layer was acidified . the precipitate formed was filtered off and dried . a mixture of the corresponding methoxycarbonyl substituted imidazoline - 2 - thione ( 9 . 34 ) ( 1 . 33 mmol ) was stirred in nh 3 / meoh for 2 days . after removing the solvent the precipitate formed was recrystallized from meoh / water ( 1 : 3 ) to yield 9 . 38 in 73 % yield . 1 h - and 13 c - data of 1 - amino - 2 , 3 - dihydro - 1h - imidazoline - 2 - thiones 9 are collected in tables 3 and 4 from which the 2 - thione structure was deduced . [ i . m . lagoja , a . van aerschot , c . hendrix , p . herdewijn , collect . czech . chem . commun . 2000 , 65 , 1145 – 1155 . ] yield : 82 (%); mp : 215 – 217 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 55 ; exact mass ( c 16 h 15 cln 3 s ): calcd . : 316 . 0675 [ m + h ] + , found : 316 . 0660 . [ i . m . lagoja , a . van aerschot , c . hendrix , p . herdewijn , collect . czech . chem . commun . 2000 , 65 , 1145 – 1155 . ] yield : 86 (%); mp : 220 – 221 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 54 ; exact mass ( c 16 h 15 cln 3 s ): calcd . : 316 . 0675 [ m + h ] + , found : 316 . 0703 . yield : 68 (%); mp : 228 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 53 ; exact mass ( c 16 h 15 fn 3 s ): calcd . : 300 . 0971 [ m + h ] + , found : 300 . 0996 . [ j . g . schantl , i . m . lagoja , heterocycles , 1997 , 45 , 691 . ] yield : 85 (%); mp : 212 – 214 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 54 ; exact mass ( c 16 h 15 cln 3 s ): calcd . : 316 . 0675 [ m + h ] + , found : 316 . 0662 . yield : 86 (%); mp : 196 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 52 ; exact mass ( c 16 h 14 brcln 3 s ): calcd . : 393 . 9790 [ m + h ] + , found : 393 . 9839 . yield : 84 (%); mp : 220 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 52 ; exact mass ( c 16 h 14 brcn 3 s ): calcd . : 393 . 9790 [ m + h ] + , found : 393 . 97788 . yield : 85 (%); mp : 204 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 52 ; exact mass ( c 16 h 14 cl 2 n 3 s ): calcd . : 350 . 0855 [ m + h ] + , found : 350 . 0271 . yield : 82 (%); mp : 225 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 52 ; exact mass ( c 16 h 14 cl 2 n 3 s ): calcd . : 350 . 0855 [ m + h ] + , found : 350 . 0356 . yield : 88 (%); mp : 226 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 53 ; exact mass ( c 17 h 17 cln 3 os ): calcd . : 346 . 0781 [ m + h ] + , found : 350 . 0831 . yield : 83 (%); mp : 238 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 53 ; exact mass ( c 16 h 15 cln 3 s ): calcd . : 316 . 0675 [ m + h ] + , found : 316 . 0684 . yield : 79 (%); mp : 148 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 52 ; exact mass ( c 13 h 15 cln 3 s ): calcd . : 280 . 0675 [ m + h ] + , found : 280 . 0733 . [ j . g . schantl , i . m . lagoja , heterocycles , 1997 , 45 , 691 . ] yield : 92 (%); mp : 224 – 226 ° c . ( meo ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 49 ; exact mass ( c 16 h 15 n 3 s ): calcd . : 282 . 1065 [ m + h ] + , found : 282 . 1037 . yield : 62 (%); mp : 228 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 53 ; exact mass ( c 16 h 20 n 3 s ): 310 . 1378 [ m + h ] + , found : 310 . 1373 . yield : 52 (%); mp : 190 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 52 ; exact mass ( c 16 h 14 brn 3 s ): calcd . : 360 . 0170 [ m + h ] + , found : 360 . 0168 . yield : 32 (%); mp : 190 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 52 ; exact mass ( c 17 h 16 cln 3 s ): calcd . : 330 . 0832 [ m + h ] + , found : 330 . 0834 . yield : 60 (%); mp : 266 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 54 ; exact mass ( c 16 h 14 cl 2 n 3 s ): calcd . : 350 . 0285 [ m + h ] + , found : 350 . 0248 . yield : 48 (%); mp : 214 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 49 ; exact mass ( c 16 h 14 n 2 o 2 s ): calcd . : 327 . 0916 [ m + h ] + , found : 327 . 0928 . yield : 36 (%); mp : 226 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 53 ; exact mass ( c 16 h 14 fn 3 s ): calcd . : 300 . 0971 [ m + h ] + , found : 300 . 0933 . yield : 58 (%); mp : 206 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 53 ; exact mass ( c 17 h 17 n 3 s ): calcd . : 296 . 1221 [ m + h ] + , found : 296 . 1208 . yield : 87 (%); mp : 234 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 54 ; exact mass ( c 11 h 13 cln 3 s ): calcd . : 254 . 05187 [ m + h ] + , found :. 254 . 0521 . yield : 78 (%); mp : 217 – 219 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 53 ; exact mass ( c 11 h 14 n 3 s ): calcd . : 220 . 0908 [ m + h ] + , found : 220 . 0844 . yield : 85 (%); mp : 230 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 54 ; exact mass ( c 12 h 16 n 3 s ): calcd . : 234 . 1065 [ m + h ] + , found :. 234 . 1078 . yield : 46 (%); mp : 220 – 222 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 50 ; exact mass ( c 19 h 22 n 3 s ): calcd . : 324 . 1534 [ m + h ] + , found :. 324 . 1524 . yield : 68 (%); mp : 116 – 118 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 52 ; exact mass ( c 17 h 17 n 3 cls ): calcd . : 330 . 0831 [ m + h ] + , found :. 330 . 0833 . yield : 72 (%); mp : 202 – 204 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 53 ; exact mass ( c 18 h 20 n 3 s ): calcd . : 310 . 1377 [ m + h ] + , found :. 310 . 1375 . yield : 56 (%); mp : 178 – 180 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 57 ; exact mass ( c 21 h 17 n 3 cls ): calcd . : 378 . 0832 [ m + h ] + , found : 378 . 0863 . yield : 68 (%); mp : 194 – 196 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 49 ; exact mass ( c 12 h 13 n 3 o 2 cls ): calcd . : 298 . 0417 [ m + h ] + , found : 298 . 0421 . yield : 52 (%); mp : 166 – 168 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 30 ; exact mass ( c 11 h 11 n 3 o 2 cls ): calcd . : 284 . 0261 [ m + h ] + , found : 284 . 0261 . yield 75 (%); mp : 160 – 162 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 45 ; exact mass ( c 12 h 13 n 3 o 2 cis ): calcd . : 298 . 0417 [ m + h ] + , found : 298 . 0410 . yield : 82 (%); mp : 240 – 242 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 53 ; exact mass ( c 18 h 20 n 3 s ): calcd . : 310 . 1378 [ m + h ] + , found : 310 . 1394 . yield : 80 (%); mp : 184 – 186 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 53 ; exact mass ( c 17 h 18 n 3 os ): calcd . : 312 . 1171 [ m + h ] + , found : 312 . 1188 . yield : 84 (%); mp : 168 – 170 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ) 0 . 53 ; exact mass ( c 17 h 14 n 4 cls ): calcd . : 341 . 0628 [ m + h ] + , found : 341 . 0675 . yield : 88 (%); mp : 160 – 162 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 53 ; exact mass ( c 19 h 17 n 4 s ): calcd . : 321 . 1174 [ m + h ] + , found : 321 . 1152 . yield : 90 (%); mp : 170 – 172 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 54 ; exact mass ( c 18 h 17 n 3 clo 2 s ): calcd . : 374 . 0730 [ m + h ] + , found : 374 . 0757 . yield : 80 (%); mp : 164 – 166 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 52 ; exact mass ( c 19 h 20 n 3 o 2 s ): calcd . : 354 . 1276 [ m + h ] + , found : 354 . 1305 . yield : 70 (%); mp : 170 – 172 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 34 ; exact mass ( c 17 h 15 n 3 clo 2 s ): calcd . : 360 . 0573 [ m + h ] + , found : 360 . 0608 . yield : 61 (%); mp : 166 – 168 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 33 ; exact mass ( c 18 h 18 n 3 o 2 s ): calcd . : 340 . 1119 [ m + h ] + , found : 340 . 1147 . yield : 73 (%); mp : 164 – 166 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 99 : 1 ): 0 . 35 ; exact mass ( c 17 h 16 n 4 os ): calcd . : 359 . 0733 [ m + h ] + , found : 359 . 0702 . [ j . g . schantl , i . m . lagoja , heterocycles , 1998 , 48 , 929 .] a suspension of the respective 1 - amino - 2 , 3 - dihydro - 1h - imidazole - 2 - thione 9 ( 2 mmol ) in glacial acetic acid ( 10 ml ) was stirred in an ice - bad . upon dropwise addition of 30 % hydrogen peroxide ( 1 ml , 9 . 76 mmol ) the reaction mixture cleared up resulting in a clear brown solution . after stirring for another 15 min the reaction mixture was made alkaline ( ph 8 – 9 ) with 10 % naoh . the resulting precipitate was filtered off , washed with cold water and recrystallized from water . the corresponding methoxycarbonyl substituted imidadazoline - 2 - thione derivative ( 1 . 33 mmol ) ( 9 . 34 , 9 . 35 , respectively ) was treated with h 2 o 2 ( 30 %) in a 10 % solution of naoh ( 25 ml ) for 6 h . after washing with ch 2 cl 2 to remove impurities , the aqueous layer was acidified . the precipitate formed was filtered off and dried . 1 h - and 13 c - data imidazoles 13 are collected in tables 5 and 6 . yield : 88 (%); mp : 218 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 82 ; exact mass ( c 16 h 15 cln 3 ): calcd . : 284 . 0945 [ m + h ] + , found : 284 . 0955 . yield : 52 (%); mp : 164 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 85 ; exact mass ( c 16 h 13 brcln 3 ): calcd . : 36 . 0059 [ m + h ] + , found : 362 . 0062 . yield : 66 (%); mp : 168 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 83 ; exact mass ( c 16 h 13 cl 2 n 3 ): calcd . : 318 . 0565 [ m + h ] + , found : 318 . 0616 . yield : 76 (%); mp : 180 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 76 ; exact mass ( c 13 h 14 cln 3 ): calcd . : 248 . 0954 [ m + h ] + , found : 248 . 0953 . [ j . g . schantl , i . m . lagoja , heterocycles , 1998 , 48 , 929 . ] yield : 86 (%); mp : 165 – 167 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 84 ; exact mass ( c 16 h 16 n 3 ): calcd . : 250 . 1344 [ m + h ] + , found : 250 . 1322 . [ j . g . schantl , i . m . lagoja , heterocycles , 1998 , 48 , 929 . ] yield : 67 (%); mp : 178 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): $$ 0 . 76 ; exact mass ( c 11 h 13 n 3 ): calcd . : 188 . 1188 [ m + h ] + , found : 188 . 1153 . yield : 82 (%); mp : 146 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 77 ; exact mass ( c 11 h 13 cln 3 ): calcd . : 222 . 0798 [ m + h ] + , found : 222 . 0793 . yield : 86 (%); mp : 144 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 78 ; exact mass ( c 12 h 16 n 3 ): calcd . : 202 . 1344 [ m + h ] + , found : 202 . 1356 . yield : 75 (%); mp : 159 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 84 ; exact mass ( c 17 h 18 n 3 ): calcd . : 264 . 1500 [ m + h ] + , found : 264 . 1536 . yield : 79 (%); mp : 155 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 76 ; exact mass ( c 16 h 15 fn 3 ): calcd . : 268 . 1250 [ m + h ] + , found : 268 . 1237 . yield : 81 (%); mp : 158 – 160 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 85 ; exact mass ( c 18 h 20 n 3 ): calcd . : 278 . 1657 [ m + h ] + , found : 278 . 1641 . yield : 81 (%); mp : 138 – 140 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 85 ; exact mass ( c 18 h 20 n 3 ): calcd . : 278 . 1657 [ m + h ] + , found : 278 . 1641 . yield : 66 (%); mp : 154 – 156 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 86 ; exact mass ( c 18 h 20 n 3 ): calcd . : 278 . 1657 [ m + h ] + , found : 278 . 1636 . yield : 68 (%); mp : 156 – 158 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 84 ; exact mass ( c 17 h 18 n 3 o ): calcd . : 280 . 1450 [ m + h ] + , found : 280 . 1449 . yield : 75 (%); mp : 140 – 142 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 84 ; exact mass ( c 17 h 14 n 4 cl ): calcd . : 309 . 0907 [ m + h ] + , found : 309 . 0911 . yield : 70 (%); mp : 138 – 140 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 84 ; exact mass ( c 18 h 17 n 4 ): calcd . : 289 . 1453 [ m + h ] + , found : 289 . 1456 . yield : 84 (%); mp : 228 – 230 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 67 ; exact mass ( c 17 h 16 n 4 ): calcd . : 327 . 1013 [ m + h ] + , found : 327 . 1017 . yield : 70 (%); mp : 220 – 222 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 66 ; exact mass ( c 18 h 19 n 4 o ): calcd . : 307 . 1556 [ m + h ] + , found : 307 . 1544 . yield : 65 (%); mp : 172 – 174 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 80 ; exact mass ( c 18 h 17 n 3 clo 2 ): calcd . : 342 . 1009 [ m + h ]+, found : 342 . 1015 . yield : 77 (%); mp : 176 – 178 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 63 ; exact mass ( c 17 h 15 n 3 clo 2 ): 328 . 0853 [ m + h ] + , found : 328 . 0854 . a mixture of 1 -( 3 - chlorophenylamino )- 2 , 3 - dihydro - 4 - methyl - 5 - phenyl - 1h - imidazoline - 2 - thione ( 9 . 01 ) ( 0 . 1 g , 0 . 37 mmol ) and methyl iodide ( 1 . 19 g , 8 . 40 mmol ) in dichloromethane ( 5 ml ) was heated under reflux for 1 h . excess of methyl iodide and solvent were removed in vacuo . further purification was achieved by recrystallisation from ch 2 cl 2 / n - hexane 1 : 1 . yield : 98 (%); mp : 215 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 48 ; 1 h - nmr ( dmso - d6 , 200 mhz ): δ = 2 . 33 ( 3h , s , 4 - me ), 2 . 73 ( 3h , s , s - me ), 6 . 37 ( 1h , d , j = 8 . 0 hz , 6 - h , n — ar ), 6 . 49 ( 1h , s , 2 - h , n — ar ), 6 . 75 ( 1h , d , j = 7 . 6 hz , 4 - h , n — ar ), 7 . 67 ( 1h , dd , j 1 = 7 . 6 hz , j 2 = 8 . 0 hz , 5 - h , n — ar ), 7 . 31 – 7 . 34 ( 5h , m , 5 - ph ), 9 . 97 ( nnh ); 13 c - nmr ( dmso - d6 , 50 mhz ): δ = 9 . 1 ( s - me ), 13 . 2 ( 4 - me ), 126 . 2 , 127 . 2 , 127 . 9 , 128 . 1 ( 1 - c , 2 , 6 - ch , 3 , 5 - ch , 4 - ch 5 - ph ), 109 . 3 , 110 . 8 , 119 . 7 , 129 . 1 , 133 . 0 , 144 . 5 ( 6 - ch , 2 - ch , 4 - ch , 5 - ch , 3 - c , 1 - c n — ar ), 123 . 1 , 129 . 8 , 144 . 8 ( 5 - c , 4 - c , 2 - c imidazole ); exact mass ( c 17 h 17 cln 3 s ): calcd . : 330 . 0832 [ m + h ] + , found : 330 . 0837 . a mixture of 1 -( 3 - chlorophenylamino )- 2 , 3 - dihydro - 4 - methyl - 5 - phenyl - 1h - imidazoline - 2 - thione ( 9 . 01 ) ( 0 . 2 g , 0 . 62 mmol ) and benzylchloride ( 0 . 08 g , 0 . 62 mmol ) in pyridine ( 5 ml ) was heated under reflux for 3 h . after removing the solvent the crude product was purified by column chromatography ( silica gel , ethyl acetate / hexane = 2 : 1 . yield : 97 (%); mp : 130 ° c . ( meoh ); rf ( ch 2 cl 2 : meoh = 9 : 1 ): 0 . 21 ; 1 h - nmr ( dmso - d6 , 200 mhz ): δ = 2 . 35 ( 3h , s , 4 - me ), 4 . 12 ( 2h , s , ch 2 s ), 6 . 24 ( 1h , d , j = 8 . 0 hz , 6 - h , n — ar ), 6 . 44 ( 1h , dd , j 1 = 7 . 6 hz , j 2 = 8 . 0 hz , 5 - h , n — ar ), 6 . 55 ( 1h , s , 2 - h , n — ar ), 6 . 83 ( 1h , d , j = 7 . 6 hz , 4 - h , n — ar ), 7 . 02 – 7 . 33 ( 10h , m , 5h 5 - ph + 5h s - bn ), 10 . 0 ( 1h , s , nnh ); 13 c - nmr ( dmso - d6 , 50 mhz ): δ = 13 . 9 ( 4 - me ), 39 . 0 ( ch 2 s ), 127 . 6 , 128 . 3 , 129 . 1 , 137 . 6 ( 4 - ch , 2 , 6 - ch , 3 , 5 - ch , 1 - c bn ), 127 . 7 , 128 . 6 , 128 . 8 , 128 . 9 , ( 4 - ch , 2 , 6 - ch , 3 , 5 - ch , 1 - c 5 - ph ), 110 . 7 , 112 . 8 , 121 . 1 , 130 . 3 , 134 . 9 , 140 . 6 ( 6 - ch , 2 - ch , 4 - ch , 5 - ch , 3 - c , 1 - c n — ar ), 130 . 2 , 135 . 0 , 147 . 9 ( 5 - c , 4 - c , 2 - c imidazole ); exact mass ( c 23 h 21 cln 3 s ): calcd . : 406 . 1145 [ m + h ] + , found : 406 . 1165 . a rapid and automated assay procedure was used for the in vitro evaluation of anti - hiv agents . an htlv - 1 transformed t4 - cell line mt - 4 , which was previously shown to be highly susceptible to and permissive for hiv infection , served as the target cell line . inhibition of the hiv - induced cytopathogenic effect was used as the end point . the viabitlity of both hiv - and mock - infected cells was assessed spectrophotometrically via in situ reduction of 3 -( 4 , 5 - dimethylthiazol - 2 - yl )- 2 , 5 - diphenyltetrazolium bromide ( mtt ). the 50 % cytotoxic concentration ( cc 50 in μg / ml ) was defined as the concentration of compound that reduced the absorbance of the mock - infected control sample by 50 %. the percent protection achieved by the compound in hiv - infected cells was calculated by the following formula : ( od t ) hiv - ( od c ) hiv ( od c ) mock - ( od c ) hiv ⁢ ⁢ expressed ⁢ ⁢ in ⁢ ⁢ % whereby ( od t ) hiv is the optical density measured with a given concentration of the test compound in hiv - infected cells ; ( od c ) hiv is the optical density measured for the control untreated hiv - infected cells ; ( od c ) mock is the optical density measured for the control untreated mock - infected cells ; all optical density values were determined at 540 nm . the dose achieving 50 % protection according to the above formula was defmed as the 50 % inhibitory concentration ( ic 50 in μg / ml ). the ratio of cc 50 to ic 50 was defined as the selectivity index ( si ). the compounds of formula ( 9 and 13 ) were shown to inhibit hiv effectively . examples of ic 50 , cc 50 and si values for inhibition of proliferation of hiv by particular compounds of formula ( i ) are listed in table 7 herein below . examples of inhibition of cell proliferation by particular compounds of formula ( i ) can be found by looking at the respective cc 50 values in the mt - 4 cell line . cells : mt - 4 cells ( miyoshi et al ., 1982 ) were grown and maintained in rpmi 1640 medium supplemented with 10 % heat - inactivated fetal calf serum , 2 mm 1 - glutamine , 0 . 1 % sodium bicarbonate , and 20 œg of gentamicin per ml . viruses : the hiv - 1 ( nl4 . 3 ) strain ( adachi et al ., 1986 ) is a molecular clone obtained from the national institutes of health ( bethesda , md .). the hiv - 2 ( rod ) ( barr ,- sinoussi et al ., 1983 ) stock was obtained from culture supernatant of hiv - 2 infected cell lines . adachi , a ., gendelman , h ., koenig , s ., folks , t ., willey , r ., rabson , a . and martin , m ( 1986 ) production of acquired immunodeficiency syndrome - associated retrovirus in human and nonhuman cells transfected with an infectious molecular clone , j . virol ., 59 , 284 – 291 . barr - sinoussi , f ., chermann , j . c ., rey , f ., nugeyre , m . t ., chamaret , s ., gruest , j ., dauguet , c ., axler - blin , c ., v , zinet - brun , f ., rouzioux , c ., rozenbaum , w ., montagnier , l . ( 1983 ) isolation of a t - lymphotropic retrovirus from patient at risk for aids , science ( wash d . c .) 220 , 868 – 871 . miyoshi , i ., taguchi , h ., kobonishi , i ., yoshimoto , s ., ohtsukj , y ., shiraishi , y . andakagi , t . ( 1982 ) type c virus - producing cell lines derived from adult t cell leukemia , gann mongr , 28 , 219 – 228 .