Title of Invention	"A PROCESS FOR THE PREPARATION OF (S) -2-CHLORO-3-(4-BENZAMIDOACETOPHENYL)-1-(4'-OCTYLOXYBENZOYL)-BENZOATOPROP IONATE"
Abstract	A process for the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl) -1- (4'-octadecyloxybenzoyl) benzoatopropionate which comprises in the step of: a first step of preparation of (S)-2-chloro-3- (4-hydroxyphenyl)-propionic acid by nucleophilic substitution of -NHa group from (S)-2-amino-3- (4-hydroxyphenyl)-propionic acid by a chlorine atom via diazonium salt formation, in the presence of pulverized sodium nitrate,

Title of Invention

"A PROCESS FOR THE PREPARATION OF (S) -2-CHLORO-3-(4-BENZAMIDOACETOPHENYL)-1-(4'-OCTYLOXYBENZOYL)-BENZOATOPROP IONATE"

Abstract

A process for the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl) -1- (4'-octadecyloxybenzoyl) benzoatopropionate which comprises in the step of: a first step of preparation of (S)-2-chloro-3- (4-hydroxyphenyl)-propionic acid by nucleophilic substitution of -NHa group from (S)-2-amino-3- (4-hydroxyphenyl)-propionic acid by a chlorine atom via diazonium salt formation, in the presence of pulverized sodium nitrate,

Full Text	FIELD OF INVENTION This invention relates to the compound (S)-2-Chloro-3-(4-benzamidoacetophenyl) -1(4 '-octadecyloxybenzoyl) - benzoatopropionate and a process for the preparation thereof. The compound of the present invention is ferroelectric (FLC) liquid crystal at room temperature which is useful in the applicational aspects such as polarisation controllers, switching attenuators and display devices. The compound has the formula as shown in Fig. 1 of the accompanying drawings. PRIOR ART Hitherto there were no process for synthesizing these room temperature ferroelectric compounds made out of optically active (S)-2-amino-3- (4-hydroxyphenyl)-propionic acid. OBJECTS OF THE INVENTION The main object of the present invention is to provide a process for the synthesis of new ferroelectric liquid crystal compound, (S) -2- Chloro-3- (4-benzamidoacetophenyl)-l- (4'-octadecyloxybenzoyl) benzoatopropionate, which exhibits ferroelectricity at ambient temperature. DESCRIPTION OF THE INVENTION According to this invention there is provided a process for the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl) -1- (4'- octadecyloxybenzoyl) -benzoatopropionate which comprises in the step of: i) a first step of preparation of (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid by nucleophilic substitution of -NH2 group from (S)-2-amino-3-(4-hydroxyphenyl)-propionic acid by a chlorine atom via diazonium salt formation, in the presence of pulverized sodium nitrate, ii) a second step of preparation of l-chloro-2-benzamidoacetic acid by refluxing as herein described 2-benzamidoacetic acid with thionyl chloride, iii) a third step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenylj-propionic acid which comprises in reacting (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid with l-chloro-2-benzamidoacetic acid in presence of a catalyst triethylamine in dry organic solvent selected from dichloromethane, benzene, methonal, dimethyl for manide, diethylether under inert atmosphere of nitrogen; iv) a fourth step of preparation of (S)-l, 2-dichloro-3-(4-benzamidoacetophenylj-propionic which comprises in refluxing (S)-2-chloro-3-(4-benzamidoacetophenyl-propionic acid with thionyl chloride; v) a fifth step of preparation (S)~2-chloro-3-(4-benzamidoacetophenyl)-1-benzole acid propionate by reacting (S)-1,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid with 4-hydroxybenzoic acid in presence of said catalyst, in said dry organic solvent under inert atmosphere; vi) a sixth step of preparation of (S)-2~chloro-3-(4-benzamidoacetophenyl) -1 -(1 -chlorobenzoic acid) propionate which comprises in reacting (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acid propionate with thionyl chloride, vii) a seventh step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-1 -(4'-benzoic acid)-benzoatopropionate by reacting (S)-2-chloro-3-(4-benzamidoacetophenyl) -1 -(1 -chlorobenzoic acid) with 4-hydroxybenzoic acid in presence of said catalyst, in said dry organic solvent under inert atmosphere, viii) an eighth step of preparation (S)-2-chloro-3-(4- benzamidoacetophenyl)-l-(4' -1—chiorobenzoic acid)- benzoatopropionate which comprises in reacting (S)-2-chloro-3- (4-benzamidoacetophenyl)-l-4'- benzoic acid)- benzoatopropionate with thionyl chloride, ix) a ninth step of preparationof (S)-2-chloro-3-(4- benzamidoacetophenyl)-1 -(4'-octadecyloxybenzoyl)- benzoatopropionate which comprises in reacting (S)-2-chloro-3- (4-benzamidoacetophenyl)-1 -(4'-1 -chlorobenzoic acid)- benoatopropionate with 1-octadecanol in presence of said catalyst, in said dry organic solvent under inert atmosphere. According to the present invention, preparation of this material comprises a total of nine steps followed by various compositions under different conditions: The first step comprises: the process of nucleophilic substitution of group from (S)-2-amino-3-(4-hydroxyphenyl)-propionic acid by a chlorine atom via diazonium salt formation, in the presence of freshly pulverised sodium nitrate, stirring the reaction mixture at 0-4°C, extracting with organic solvent such as acetone, acetonitrite, petroleum ether, dichloromethane, drying the organic layer with a drying agent such as sodium sulphate, phosphorous pentoxide, calcium chloride, removing the excess solvent under reduced pressure, separating the cpmpound by column chromatography using a silica gel column and a mixture of diethylether and acetone, followed by recrystallization to get crystals of (S)-2-chloro-3-(4-hydrooxphenyl)-propionic acid. column and appropriate eluent mixture, followed tay recrystallization to get crystals of (S)-2-chloro 3-(4- hydroxypheny1)-propionic acid. Second step of the process illustrates the preparation of l-chloro-2—bert2amidoacetic acid by refluxing 2~benzamidoacetic acid with thionyl chloride at 7 5 t for 8 hours, r e m o v i ng the excess orc\anic solvent by vacuum distillation, washing the product with suitable cold solvent, drying the product. over an appropriate desiccarit for a period of 10 hours, separating the compound by column chromatograpny using a silica gel column and appropriate eluent mixture. Third step of the process describes the preparation of (S ) -2-chloro-3- ( 4-benzamidoacetopheny 1 ) -propionic acid which comprises in reacting (S)-2- chloro-3- ( 4--hydroxypheny 1 )-propionic acid with 1chloro-2-benzamidoacetic acid in presence of a su11 able catalyst, in dry organic solvent under inert atmosphere, stirring the reaction mixture initially at room temperature for 2 hours, refluxing the reaction mixture for a period upto 12 hours., removing the excess organic solvent by vacuum distillation,, washing the product: with suitable cold solvent, drying the product over an appropriate desiccant for a period of 12 hours, separating the compound by column chromatoqraphy using a silica gel column and appropriate eluent mixture, followed by recrystal1ization to get crystals of (S)-2- chloro-3- ( 4—benzamidoacetopheny 1 ) -propionic: ac id . Fourth step of the process describes the preparation of (S)-i,2-dich]or n -3-(4- benzamidoacetopheny1)—propionic acid which comprises in reflux ing (S)-2-chloro-3- ( 4-benzarnidoacertopheny 1 )- propionic: acid with thionyl chloride at 60 C with constant stirring, removing the excess organic: solvent by vacuum distillation, washing the product with suitable cold solvent, drying the product over an appropriate desiccant for a period of .10 hours, separating the compound by column chromatoqraphy using a silica gel column and appropriate eluent mixture, followed by recrystal1ization to get crystals of (S)-l, 2-dichloro-3-(-4-benzamidoace topheny 1 )-propionic acid . Fifth step of the process describes the preparation of (S)-•-2-chlora~3~(4-benzamidoacetophenyl)- l-benzoic acid propionate by reacting (S)-.l., 2- -d i chloro-3-(4-benzamidoacetophenyl)-propionic acid with 4- hydroxybensoic acid in presence of a suitable? catalyst, in dry organic solvent, under inert atmosphere, stirring the reaction mixture initially at room temperature for 4 hours, refluxing the reaction mixture for a period upto 18 hours, removing the excess organic solvent, by vacuum distillation, washing the product with suitable cold solvent, drying the product over an appropriate desiccant for a period of 12 hours, separating the compound by column chromatography using a silica gel column and appropriate eluent mixture. Sixth step of the process describes the preparation of (S)-2-chlaro-~3-(4-ben2amidoac:etophenyl )- 1—(1-chlorobenzoic acid) propionate which comprises in reacting (S)-2-chloro-3-(4-ben2amidoacet.ophenyl )-l- bensoic. acid propionate with thionyl chloride at 60° with constant stirring, removing the excess organic solvent by vacuum distillation, washing the product with suitable cold solvent, drying the product over an appropriate desiccant for a period of 10 hours, separating the compound by column chromatography using a silica gel column a\nd appropriate eluent mixture, followed tay recrystallization to get crystals of (S)-2-chloro-3- (4-benzamidoacetopheny1 )-!-(l-chlorobenzoic acid) propionate. Seventh step of the process dpscribes the preparation of (S) -2~chloro-3-(4-benzamidacf-:etophenyl)-1- ( 4 ' —benzoic acid ) —benzoatopro-pionate by rearting(S)- 2-chloro-3-( 4-benzamidoacetopheny 1 ) -l-( l-chlorobenzoic acid) propionate with 4-hydroxybenzoic acid in presence of a suitable catalyst, in dry organic solvent under inert atmosphere, stirring the reaction mixture initially at room temperature for 4 hours, re fluxing the reaction mixture for a period upto 92 hours, removing the excess organic solvent by vacuum distillation, washing the product with suil.Ml.ile cold solvent, drying the product over an appropriate desiccant for a period of .1.2 hours, separating the compound by column chromatography using a silica gel column and appropriate eluent mixture. Eight step of the process describes the preparation of (S)-2-chloro-3-4-benzamidoacetophenyl )-l- (4' -l-chlorobenzoic. acid ) -benzoatopropiona te which comprises in reacting (S) 7 "chloro-3-(4- benzamidoacetopheny1 ) -1-4 ' --benzoic acid) - benzoatopropionate with thionyl chloride at 60/Pc with constant. stirring, removing the excess organic solvent by vacuum distillation, washing the product with suitable cold solvent, drying the product over an appropriate desiccant for a period of12hours, separating the compound by column chromatography using a silica gel column and appropriate eluent mixturn. Ninth step of the process deserbos the preparation of ( S ) —2-chloro-3- ( 4-benzamidoa<::c b ipheny zoat opro piona tc which> comprises in reacting (S)-2 chloro-3-(4- benzamidoacetopheny1)-I-(4'-1—chlorobenzoic acid)- benzoatopropionate with 1-octadecanol in presence of a suitable catalyst, in dry organic solvent under inert atmosphere, stirring the reaction mixture initially at room temperature for 4 hours, refluxing the reaction mixture for a period upto 22 hours, removing the excess organic: solvent by vacuum distillation, wasting the product with suitable cold solvent, drying the product over an appropriate desiccant for a period of 12 hours,separating the compound by column chroma tog raphy using a silica gel column and appropriate eluent mixlure. According to another feature of the present invention, the inert, atmosphere may be maintained by using nitrogen. According to yet another feature of the present invention, the catalyst used is snrh as t r i e t h y 1 a m i. n e. According to yet another feature of the present invention, the dry organic solvent used is such as dichloromethane, benzene, methanol, dimethylformamide, diethylather. According to yet another feature of the present invention, organic solvent used for purification of compound by column chromatography is such as acetone, acetonitrile, petroleum ether, dichloromethane. According to yet another feature of the present invention, drying agent used is such as sodium sulphate, phosphorous pentoxide, calcium chloride. A step wise process for the preparation of a. room temperature feiroelectric liquid nyslil cimpound, (s)-2-cliloro-3-(4-beiizmnidoacctophenyl)-l-('4>-odaidccyloxybeuzoyl)-bcrizoato rpioiate, is presented as follows : Step 1 (S)-2-amino-3-(4-hydroxyphenyl)-propionic acid - (S)-2-cliloro-3-(4- hydroxyplicnyl) puipioinic acid (S)-2-chioro-3-(4-hydroxyphenyl)-propionic acid was prepared by a known method and is descibed frst. 5.43 gram (30.0 minol) of (S)-2-aniuo-3-(4-hydroxyphetiyI)-propionic acid WAS dissolved in 20 ml of 6.0 N IIC1 and the solution was brought to 0 °C. 2.72 gram (32.0 mmol) of fiesily pulverised sodium nitrate was added to the solution in small portions with vigorous stiiring while maintining the reaction temperature between 0 and 5 °C. The reaction mixture was stirred for 16 li. The solution was then extracted with 40 ml of diethylether and the etherinl layer was dried over anhydrous sodium sulphate for 12 h. (S)-2-chioro-3-(4-hydroxyphenyl)-propionic acid obtained as an yellow product on removing the excess solvent by distillation under reduced pressure was repeatedly with cold benzene, • • r ' ' separated by cliromatography through a silica gel column using a mixture of diethyldhcr : acetone (5:1 v/v) as eluent. The product was recrystallized J5om hot dichloromethane and dried over p2O-, for 12 h. to get an yield of 3.2 gram (53.2 %). Step 2 2-benzamidoacetic acid l-chloro-2-benznniidoacetic aeid l-chloro-2-benzanmidoacetic acid was prepared by mixing togetlier 4.48 gram (25.0 mmol) of 2-benzamidoacetic acid and 3.0 ml (40.0 mmol) of thionyl chloride in 40 ml of dry benzcnc under nitrogen atmosphere and kept the reaction mixture under reflux with continuous stirring at 75 °C for 8 h. After the evalution of SO2 gas was ceased, the volume of the resulting solution was reduced by vacuum distillation to get an yellow solid product which was suction filtered., washed several times witll Cold methanol and dried over anhydrous calcium chloride for 10 h. The product was purified by passing tlirough a silica gel column using a mixlue of petroleum ether : acetonitrile (5 : I v/v) as eluent to get 2.6 gram (52.6 %) of l-chloro-2-benzarnitbacclie acid. Step 3 l-chloro-2-benzamidoacetic acid I (S)-2-chloro-3-(4-hydroxyphenyl)-pro\|pkmic acid (S)-2-chloro-3-('1-bon?.;mii(loace(ophenyl)-propionic acid 3.95 gram (20.0 mniol) of l-chloro-2-ben/.amidoacetie acid prepared as iiluslialed in slop 2 and 5.0 gram. (25.0 rranol) of (S)-2-chloro-3-(4-hydroxyphenyI)-propionic acid prepared ;is described in step 1 were magnetically stirred in 40 ml dry dichloromefhane at ambient tomporalm •• lot!. n 5 ml ( >. (S)-2-chloro-3-(4-beri7'.ajaidoacctophcnyl)-propionic acid -- (S)-l,2-dicliloro- 3-('1-be»2aiiiidoaceto]iiicnyl)-]ii opionic acid (o)-],2-dichloro-3-(4-ben/amidoacetoplier,yS)-propionie acid was prepared by dn;olving 5.84 jiram (16.2 niinol) of (S)-2-chloro-3-(4-berizajnidoacetophenyl)-propionic acid prepaied as illustrated in stop 3 in 40 ml of absolute dichlorometlmne and to it added 2.5 ml (21.2 nuuol) of thionylchloride witii constant stirring. 'Hie reaction miturc was- then healed to 60 °C and the stin inu, \vas continued till the evalution of SO^ ceased. On cooling the reaction mixture to room temperature (S)-l,2-dichloro-3-(4-ben/,ajnidoaccU>phcnyl)-propionic acid wan separated as a white solid which was filtered oil' and washed several times with cold chloroform and die final product was recryslalli/ed fiom hot benzene solution. 'Hie product was further purified by column cliromatogliaphy through a silica gel column using a mixture of petroleum ether and acetone in 5 : 1 v/v as eluent to get 4 . 22 gr am (68.84 %) of (S)-l,2-dichloro-3-(4-benzamidoacetophcnyl)-propionic acid. Step 5 (S)-l)2-dichloro-3-(4-bcnzunidoacetophenyI)-propionic acid + 4-hydroxybenzoic acid —~ (S)-2-chloro-3-(4-bcnzanidoacolophejiyl)-l-benzoic ncid-propionnle (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-bonzoic acid-propionate prepared by mixing together absolute dichloromethane solutions of (S)-l,2-dichloro-3-(4-benzamidoacetophenyl) propionic acid (4.81 gram/12.7 mmol in 20 ml of dry dichloromethane) prepared as described in slop 4 and 4-hydroxybenzoic acid (1.8 gram/13.0 mmol in 20 ml of dry dichloromethane) in eqnimobir ratio and the read ion mixture was stirred Ibr4 h at room temperature. 0.4 ml (3.1 mmol) of triotliylumine was then added to the reaction mixture drop wise with constant stirring. The reaction mixture was- (hen refluxed at 75 °C for 18 h. The yellow coloured solulion containing (S)-2-chloro-3-(4-benzmidoacetophenyl 1-benzoic acid-propionate was reduced by vacuum distillation and the product was washed repeatedly with cold acetonitrile solution. The product was separated by column chronafoghaphy through a silica gel column using a mixture of petroleum ether and acetonitrile in 5 : 1 v/v as eliient. The yield obtained was 3.74 gram (63.17 %). Step 6 (S)-2-chloro-3-(4-benzamidoacelophenyl)-l-benzoic acid propionate 3-(4-be!i2amidoacctophenyl)-l-(l-chlorobonzoic aud)-propionate (S)-2-chloro-3-(4-beiizamidoacetophenyl)-l-(l-chioro-beiizoic acid)-propionnle was prepared by disolving 3.32g(7.11 mmol) of (S)-2-chloro-3-(4-bcnzainidoacetophenyl)-l-benzoic acid-propionate prepai-ed as descibed in step 5 in 40 ml of absolute dicliloromethane and to it added 0.76 nil (10.4 mmol) of thionylchloride with constant stirring under nitrogen atmosphere. The reaction mixture was then heated to 60 °C and the stirring wan continued till the evolution of SO; ceased On cooling the reaction mixture to room temperature (S)-2-chloro-3-(4-benzamidoacetophonyl)-1-(i-chlorobenzoic acid)-propionate was separated as a white- product which, was filtered off and washed repeatedly with cold chloroform and the product was purified by passing through a silica gel column using a mixture of petroleum ether and acetonitrile in 5 : 1 v/v as eluent. The final product was reciyslnlli/ed from hot benzene solution' to get 1.86 gram (52.32 %) of (S)-2-chloro-3-(4-ben7,aniidoacelophenyl)-i-(l-chlorobenzoic acid)-propionate Step 7 (S)-2-diloro-3-(4-benzanmioacetophenyl)-l -(l-chlorobcnzoie acid)-propiona!e i -1 • liydi oxybcenzoic acid (S)-2-chloro-3- (4-benzamidoacetophenyl)-l-(4'-benz.oic acul)- benzoatopropionatc (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-benzoic acid)- benzoatopropionafo was prepared by mixing together absolute dichloromethane solutions of (S)-2-chloro-3-(4-ben:-"»iiidoacetophenyl)-l-(l-chlorobenzoic acid)-propionate (2.65 gram/5.3 mmol in 20 ml dry dichloromethano) prepared as illustrated in step 6 and 4-hydroxybenzoic acid (0.95 gram/68 mmol in 15 ml of dry didiloromethanc) and the reaction mixture was stirred at ambient temperature! for 4 h under nitrogen atmosphere. 0.45 ml (3.2 nrunol) of triethylamine was then added to the reaction mixture drop wise and rclluxed the reaction mixture at 75 °C will) constant stirring for 22 h. The yellow coloured solid of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-benzoic acid)-bcnzoatopropionate was separated by removing the excess solvent by vacuum distillation, washed twice with cold ethanol ami chromatogrnphed through a silica gel column using a mixture of petroleum ether : acetone (5 : 1 v/v) as cluciit. 'the product was reciyslallized from hot benzene solution. The yield obtained was 1.64 gram (51.-18 %). Step 8 (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-benzoic acid)-benzoatopropionak* ' (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-l-chlorobenzoic acid)-bcnzoatopropionatae (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4>-l-chlorobenzoic acid)-benz.onlopnopionatc was prepared by disolving 2.08 gram (3.3 mmol) of (S)-2-chloro-3-(4-benzamidoactophenyl)-l-(4'-benzoic acid)-ben2oalopropionate prepared • as described in step 7 in '10 ml of absolute dichloromelhane and to it added 0.65 ml (4.7 mmol) of thionylchloride with constant stiiring under nitrogen atmofsphere. The reaction miture was then heated to 00 °C and the stiwting WAS continued till the evalnlion of S02 ceased. On cooling the reaction mixture to room temperature (,S)-2-chloro-3-(4-beii2aniidoacelophenyl)-l-(f'-l-chlorobenzoic acid)-benz:oatopropionate was neparaled as a while colour product which was filtered off, washed repeatedly with cold chloroform and dt ied over vacuo for 12 h. (S)-2-cliloro-3-('}-benzamidoacetophenyl)-l-(4'-l-chlorobcnzoic acid)-benzoaiopropionate was purified by column chromatography through a silica gel colunu) using a mixture ofpolroloum ether : acetone (5 : 1 v/v) as eluent. The product was recrystallized from hot dichloromethanesolution to get an yield of 1.13 gram (52.64 %). (S)-2-cl]loro-3-(4-beiizaii)idoacetoph€!nyI)-l-(4'-octadecyloxybenzoyl)-ben?:o;ilo\|)ropi()nafo was prepared by mixing together absolute dichloromelhane solutions of (S)-2-chIoro-3-('l-benzamdoacetOphenyl)-l-(4'-l-chlorobcnzoic acid)-benzoatopropio- note (2.0 grnjn/3.2 niniol in 20 ml ol'diy dichloromelhane) synthesized as illustrated in step 8 and 1-octadccaiiol (1.16 grnni/4.3 nunul in 20 ml of dry dichloromcthane) under nitrogen atmosphere and the read ion mixlinv was nlirrcd nt ambient temperature for 4 h. After the addilion of 0.5ml (3.6 mniol) of litieflylaninehyliuiiiiK' Hie ronclion mixlure was reiluxed at 65 °C wthe costant stiring 22 h. the resultaiit solution containing (S)-2-chloro-3-(4-ben2amidoacetophenyl)-l-(4'-octadecyloxybcnzoyl)-benzoaloproi)i011:1(0 \vas reduced to get a bright red geily product and was washed repeatedly with a cold chloroform, the crude product afler drying over yacuuo for 12 h was purified by a silica gel column using a mixture of petrolctuu ether : acetone (5 : 1 v/v) as cluent.the yield obtained was 1.26 gram (45.73 %).ADVANTAGES The room temperature ferroelectric liquid crystal compound prepared as per the process of this invention which shows characteristic ferroelectric properties in an around room temperatures which is a rare phenomena, as the most of the reported •ferroelectric compounds used for the applicational purposes are the mixtures of more than one component. The room temperature ferroelectric: liquid crystal compound prepared as per the process of this invention is the refore use fu1 for both fun d amental a s well as applied reseairch aspects including for the nonlinear optical applications. The room temperature ferroelectric liquid crystal compound prepared as per the process of this invention can further be used as host material's for the preparation of other FLC mixtures. The need for this type of room temperature ferroelectric materials as strongly felt because the preparation and characterization of FLC maxtures is time consuming as well as expensive. These? compounds prepared as per the process of this invention can be directly used in the applicantional aspects such as polarisation controllers, switching attenuators' display devices etc. The study of the fundamental ferroelectric properties viz, spontaneous polarization, tilt angle, time response etc. of the present invented compound reveals that the magnitudes of these parameters are found to be of in good agreement with those of commercially available multi-component materials. In fact some of the above proper-ties envisage that. this compound showed better physical characteristics then the commercially available compounds. WE CLAIM; 1. A process for the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl) -1- (4'-octadecyloxybenzoyl) benzoatopropionate which comprises in the step of: i) a first step of preparation of (S)-2-chloro-3- (4-hydroxyphenyl)-propionic acid by nucleophilic substitution of -NH2 group from (S)-2-amino-3- (4-hydroxyphenyl)-propionic acid by a chlorine atom via diazonium salt formation, in the presence of pulverized sodium nitrate, ii) a second step of preparation of l-chloro-2-benzamidoacetic acid by refluxing as herein described 2-benzamidoacetic acid with thionyl chloride, iii) a third step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid which comprises in reacting (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid with l-chloro-2-benzamidoacetic acid in presence of a catalyst triethylamme in dry organic solvent selected from dichloromethane, benzene, methonal, dimethyl for manide, diethylether under inert atmosphere of nitrogen;iv) a fourth step of preparation of (S)-l, 2-dichloro-3- (4-benzamidoacetophenyl)-propionic which comprises in refluxing (S)-2-chloro-3-(4-benzamidoacetophenyl-propionic acid with thionyl chloride; v) a fifth step of preparation (S)-2-chloro-3- (4-benzamidoacetophenyl)-l-benzoic acid propionate by reacting (S)- l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid with 4-hydroxybenzoic acid in presence of said catalyst, in said dry organic solvent under inert atmosphere; vi) a sixth step of preparation of (S)-2-chloro-3- (4-benzamidoacetophenyl)-l-(l-chlorobenzoic acid) propionate which comprises in reacting (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acid propionate with thionyl chloride, vii) a seventh step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl) -1 - (4 '-benzoic acid) -benzoatopropionate by reacting (S)-2-chloro-3-(4-benzamidoacetophenyl)-1 -(1 -chlorobenzoic acid) with 4-hydroxybenzoic acid in presence of said catalyst, in said dry organic solvent under inert atmosphere, viii) an eighth step of preparation (S)-2-chloro-3- (4- benzamidoacetophenyl)-l-(4' -1—chlorobenzoic acid)- benzoatopropionate which comprises in reacting (S)-2-chloro-3- (4-benzamidoacetophenyl)-l-4'- benzoic acid)- benzoatopropionate with thionyl chloride, ix) a ninth step of preparation of (S)-2-chloro-3- (4- benzamidoacetophenyl)-l-(4'-octadecyloxybenzoyl)- benzoatopropionate which comprises in reacting (S)-2-chloro-3- (4-benzamidoacetophenyl)-1-(4'-1-chlorobenzoic acid)- benoatopropionate with 1-octadecanol in presence of said catalyst, in said dry organic solvent under inert atmosphere. 2. A process as claimed in claim 1 wherein said first step comprises in nucleophilic substitution of -NHa group from (S)-2-amino-3- (4-hydroxyphenylj-propionic acid by a chlorine atom via diazonium salt formation, in the presence of freshly pulverised sodium nitrate, stirring the reaction mixture at 0-4°C, extracting with organic solvent selected from acetone, acetonitrite, petroleum ether, dichloromethane, drying the organic layer with a drying agent selected from sodium sulphate, phosphorous pentoxide, calcium chloride, removing the excess solvent under reduced pressure, separating the compound by column chromatography using a silica gel column and a mixture of diethylether and acetone, followed by recrystallization to get crystals of (S)-2-chloro-3-(4-hydrooxpheny 1)-propionic acid. 3. A process as claimed in claim 1 wherein said second step comprises the preparation of l-chloro-2-benzamidoacetic acid by refluxing 2-benzamidoacetic acid with thionyl chloride at 75°C, removing said excess organic solvent by vacuum distillation, washing the product with cold solvent which is methonal, drying the product over drying agents selected from sodium sulphate, phosphorous pentoxide, calcium chloride and a mixture of petroleum ether and acetonitrile. 4. A process as claimed in claim 1 wherein said third step comprises the preparation of (S)-2-chloro-3- (4-benzamidoacetaphenyl)-lpropionic acid by reacting (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid with l-chloro-2-benzamidoacetic acid in presence of said catalyst in said dry organic solvent under inert atmosphere stirring the reaction mixture initially at room temperature, refluxing the reaction mixture for 12 hours, over P2Os, separating the compound by column chromatography using a silica gel column and appropriate eluent mixture of diethyl ether and acetone followed by recrystallization to get crystals of (S)-2-chloro-3-{4-benzamidoacetophenyl) -propionic acid. 5. A process as claimed in claim 1 wherein said fourth step comprises the preparation of (S)-l,2-dichloro-3- (4-benzamidoacetophenyl)- propionic acid by refluxing (S)-2-chloro-s-(4-benzamidoacetophenyl)- propionic acid with thionyl chloride with constant stirring, removing the excess organic solvent by vacuum distillation, washing the product with said cold solvent, drying the product over said desiccant, separating the compound by column chromatography using a silica gel column and appropriate eluent mixture comprising petroleum ether and acetone, followed by recrystallization to get crystals of (S)-l- 2-dichloro-3 (4-benzamidoacetophenyl)lpropionic acid. 6. A process as claimed in claim 1 wherein said fifth step comprises the preparation of (S)-2-chloro-3- (4-benzamidoacetophenyl)l-bezonic acid propionate by reacting (S)-l-, 2-dichloro-3-(4- benzamidozcetonphenyl)-propionic acid with 4-hydroxybenzoic acid in presence of said catalyst, in said dry organic solvent under inert atmosphere, stirring the reaction mixture initially at room temperature, refluxing the reaction mixture, removing the excess organic solvent by vacuum distillation, washing the product with said cold solvent, drying the product over said desiccant, separating the compound by column chromatography using silica gel column and appropriate eluent mixture comprising petroleum ether and acetonitirle. 7. A process as claimed in claim 1 wherein said sixth step comprises the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)l-(l- chlorobenzonic acid) propionate by reacting (S)-2-chloro-3-(4- benzamidoacetophenyl)-l-benzoic acid propionate with thionyl chloride with constant stirring, removing the excess organic solvent by vacuum distillation washing the product with said cold solvent, drying the product over said desiccant, separating the compound by column chromatography using a silica gel column and appropriate eluent mixture comprising petroleum ether and acetonitrile followed by recrystallization to get crystal (s)-2-chloro-3-(4-behzamidoacetopheyl)- l-(l-chlorobenzoic acid) propionate. 8. A process as claimed in claim 1 wherein seventh step comprises the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-benzoic acid) benzoato-propionate by reacting (S)-2-chloro-3-(4- benzamidoacetophenyl)-l-(l-chlorobenzoic acid) propionate with 4-hydroxybenzoic acid in presence of said catalyst, in said dry organic solvent under inert atmosphere, stirring the reaction mixture initially at room temperature, refluxing the reaction mixture, removing the excess organic solvent by vacuum distillation, washing the product with said cold solvent, drying the product over said desiccant, separating the compound by column chromatography using a silica gel column and appropriate eluent mixture comprising petroleum and acetone. 9. A process as claimed in claim 1 wherein said eight step comprises the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-l-chlorobenzoic acid) benzaotopropionate by reacting (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4' benzoic acid)-benzamidoacetophenyl) with thionyl chloride with constant stirring, removing the excess organic solvent by vacuum distillation, washing the product with said cold solvent, drying the product over said desiccant, separating the compound by column chromatography using a silica gel column and appropriate eluent mixture comprising petroleum ether and acetone. 10. A process as claimed in claim 1 wherein ninth step comprises the preparation of (S)-2-chloro-3-(4-benzamido-acetophnyl)-l-(4'- octadecyloxybenzoyl-benzoatopropionate) by reacting (S)-2-chloro-3- (4-benzamidozcetophenyl)-1 -4'-1 -chlorobenzoic acidj- benzoatopropionate with 1-octadeconal in presence of said catalyst in said dry organic solvent under inert atmosphere, stirring the reaction mixture initially at room temperature, refluxing the reaction mixture for a period, removing the excess organic solvent by vacuum distillation washing the product with said cold solvent, drying the product over said desiccant, separating the compound by column chromatography using a silicon gel column and appropriate eluent mixture of petroleum ether and acetone. 11. A process for the preparation for the preparation of (S)-2-chloro-3- (4-benzamidoacetophenyl)-1-(4' -octoadecyloxybenzoyl)- benxoatopropionate, substantially as herein describes and exemplified in the example.

Full Text

FIELD OF INVENTION
This invention relates to the compound (S)-2-Chloro-3-(4-benzamidoacetophenyl) -1(4 '-octadecyloxybenzoyl) - benzoatopropionate and a process for the preparation thereof. The compound of the present invention is ferroelectric (FLC) liquid crystal at room temperature which is useful in the applicational aspects such as polarisation controllers, switching attenuators and display devices. The compound has the formula as shown in Fig. 1 of the accompanying drawings.
PRIOR ART
Hitherto there were no process for synthesizing these room temperature ferroelectric compounds made out of optically active (S)-2-amino-3- (4-hydroxyphenyl)-propionic acid.
OBJECTS OF THE INVENTION
The main object of the present invention is to provide a process for
the synthesis of new ferroelectric liquid crystal compound, (S) -2-
Chloro-3- (4-benzamidoacetophenyl)-l- (4'-octadecyloxybenzoyl)
benzoatopropionate, which exhibits ferroelectricity at ambient temperature.
DESCRIPTION OF THE INVENTION
According to this invention there is provided a process for the
preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl) -1- (4'-
octadecyloxybenzoyl) -benzoatopropionate which comprises in
the step of:
i) a first step of preparation of (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid by nucleophilic substitution of -NH2 group from (S)-2-amino-3-(4-hydroxyphenyl)-propionic acid by a chlorine atom via diazonium salt formation, in the presence of pulverized sodium nitrate,
ii) a second step of preparation of l-chloro-2-benzamidoacetic acid by refluxing as herein described 2-benzamidoacetic acid with thionyl chloride,
iii) a third step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenylj-propionic acid which comprises in reacting (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid with l-chloro-2-benzamidoacetic acid in presence of a catalyst triethylamine in dry organic solvent selected from dichloromethane, benzene, methonal, dimethyl for manide, diethylether under inert atmosphere of nitrogen;
iv) a fourth step of preparation of (S)-l, 2-dichloro-3-(4-benzamidoacetophenylj-propionic which comprises in refluxing (S)-2-chloro-3-(4-benzamidoacetophenyl-propionic acid with thionyl chloride;
v) a fifth step of preparation (S)~2-chloro-3-(4-benzamidoacetophenyl)-1-benzole acid propionate by reacting (S)-1,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid with 4-hydroxybenzoic acid in presence of said catalyst, in said dry organic solvent under inert atmosphere;
vi) a sixth step of preparation of (S)-2~chloro-3-(4-benzamidoacetophenyl) -1 -(1 -chlorobenzoic acid) propionate which comprises in reacting (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acid propionate with thionyl chloride,
vii) a seventh step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-1 -(4'-benzoic acid)-benzoatopropionate by reacting (S)-2-chloro-3-(4-benzamidoacetophenyl) -1 -(1 -chlorobenzoic acid) with 4-hydroxybenzoic acid in presence of said catalyst, in said dry organic solvent under inert atmosphere,
viii) an eighth step of preparation (S)-2-chloro-3-(4-
benzamidoacetophenyl)-l-(4' -1—chiorobenzoic acid)-
benzoatopropionate which comprises in reacting (S)-2-chloro-3-
(4-benzamidoacetophenyl)-l-4'- benzoic acid)-
benzoatopropionate with thionyl chloride,
ix) a ninth step of preparationof (S)-2-chloro-3-(4-
benzamidoacetophenyl)-1 -(4'-octadecyloxybenzoyl)-
benzoatopropionate which comprises in reacting (S)-2-chloro-3-
(4-benzamidoacetophenyl)-1 -(4'-1 -chlorobenzoic acid)-
benoatopropionate with 1-octadecanol in presence of said catalyst, in said dry organic solvent under inert atmosphere.
According to the present invention, preparation of this material comprises a total of nine steps followed by various compositions under different conditions:
The first step comprises: the process of nucleophilic substitution of group from (S)-2-amino-3-(4-hydroxyphenyl)-propionic acid by a chlorine atom via diazonium salt formation, in the presence of freshly pulverised sodium nitrate, stirring the reaction mixture at 0-4°C, extracting with organic solvent such as acetone, acetonitrite, petroleum ether, dichloromethane, drying the organic layer with a drying agent such as sodium sulphate, phosphorous pentoxide, calcium chloride, removing the excess solvent under reduced pressure, separating the cpmpound by column chromatography using a silica gel column and a mixture of diethylether and acetone, followed by recrystallization to get crystals of (S)-2-chloro-3-(4-hydrooxphenyl)-propionic acid.

column and appropriate eluent mixture, followed tay
recrystallization to get crystals of (S)-2-chloro 3-(4-
hydroxypheny1)-propionic acid.
Second step of the process illustrates the
preparation of l-chloro-2—bert2amidoacetic acid by refluxing 2~benzamidoacetic acid with thionyl chloride at 7 5 t for 8 hours, r e m o v i ng the excess orc\anic
solvent by vacuum distillation, washing the product with suitable cold solvent, drying the product. over an
appropriate desiccarit for a period of 10 hours, separating the compound by column chromatograpny using a
silica gel column and appropriate eluent mixture.
Third step of the process describes the
preparation of (S ) -2-chloro-3- ( 4-benzamidoacetopheny 1 ) -propionic acid which comprises in reacting (S)-2-
chloro-3- ( 4--hydroxypheny 1 )-propionic acid with 1chloro-2-benzamidoacetic acid in presence of a su11 able
catalyst, in dry organic solvent under inert atmosphere, stirring the reaction mixture initially at room
temperature for 2 hours, refluxing the reaction mixture for a period upto 12 hours., removing the excess organic
solvent by vacuum distillation,, washing the product: with suitable cold solvent, drying the product over an
appropriate desiccant for a period of 12 hours, separating the compound by column chromatoqraphy using
a silica gel column and appropriate eluent mixture, followed by recrystal1ization to get crystals of (S)-2-
chloro-3- ( 4—benzamidoacetopheny 1 ) -propionic: ac id .
Fourth step of the process describes the
preparation of (S)-i,2-dich]or n -3-(4-
benzamidoacetopheny1)—propionic acid which comprises in
reflux ing (S)-2-chloro-3- ( 4-benzarnidoacertopheny 1 )-
propionic: acid with thionyl chloride at 60 C with constant stirring, removing the excess organic: solvent
by vacuum distillation, washing the product with suitable cold solvent, drying the product over an
appropriate desiccant for a period of .10 hours, separating the compound by column chromatoqraphy using
a silica gel column and appropriate eluent mixture, followed by recrystal1ization to get crystals of (S)-l,
2-dichloro-3-(-4-benzamidoace topheny 1 )-propionic acid .
Fifth step of the process describes the
preparation of (S)-•-2-chlora~3~(4-benzamidoacetophenyl)-
l-benzoic acid propionate by reacting (S)-.l., 2- -d i chloro-3-(4-benzamidoacetophenyl)-propionic acid with 4-
hydroxybensoic acid in presence of a suitable? catalyst, in dry organic solvent, under inert atmosphere, stirring
the reaction mixture initially at room temperature for 4 hours, refluxing the reaction mixture for a period upto
18 hours, removing the excess organic solvent, by vacuum distillation, washing the product with suitable cold
solvent, drying the product over an appropriate desiccant for a period of 12 hours, separating the
compound by column chromatography using a silica gel column and appropriate eluent mixture.
Sixth step of the process describes the preparation of (S)-2-chlaro-~3-(4-ben2amidoac:etophenyl )-
1—(1-chlorobenzoic acid) propionate which comprises in reacting (S)-2-chloro-3-(4-ben2amidoacet.ophenyl )-l-
bensoic. acid propionate with thionyl chloride at 60° with constant stirring, removing the excess organic
solvent by vacuum distillation, washing the product with suitable cold solvent, drying the product over an
appropriate desiccant for a period of 10 hours, separating the compound by column chromatography using
a silica gel column a\nd appropriate eluent mixture,
followed tay recrystallization to get crystals of (S)-2-chloro-3- (4-benzamidoacetopheny1 )-!-(l-chlorobenzoic
acid) propionate.
Seventh step of the process dpscribes the
preparation of (S) -2~chloro-3-(4-benzamida*cf-:etophenyl)-1- ( 4 ' —benzoic acid ) —benzoatopro-pionate by rearting(S)-
2-chloro-3-( 4-benzamidoacetopheny 1 ) -l-( l-chlorobenzoic acid) propionate with 4-hydroxybenzoic acid in presence
of a suitable catalyst, in dry organic solvent under inert atmosphere, stirring the reaction mixture
initially at room temperature for 4 hours, re fluxing the reaction mixture for a period upto 92 hours,
removing the excess organic solvent by vacuum distillation, washing the product with suil.Ml.ile cold
solvent, drying the product over an appropriate desiccant for a period of .1.2 hours, separating the
compound by column chromatography using a silica gel column and appropriate eluent mixture.
Eight step of the process describes the preparation of (S)-2-chloro-3-4-benzamidoacetophenyl )-l-
(4' -l-chlorobenzoic. acid ) -benzoatopropiona te which
comprises in reacting (S) 7 "chloro-3-(4-
benzamidoacetopheny1 ) -1-4 ' --benzoic acid) -
benzoatopropionate with thionyl chloride at 60/Pc with constant. stirring, removing the excess organic solvent by vacuum distillation, washing the product with suitable cold solvent, drying the product over an appropriate desiccant for a period of12hours, separating the compound by column chromatography using a silica gel column and appropriate eluent mixturn.
Ninth step of the process deserbos the preparation of ( S ) —2-chloro-3- ( 4-benzamidoa<::c b ipheny zoat opro piona tc which> comprises in reacting (S)-2 chloro-3-(4-
benzamidoacetopheny1)-I-(4'-1—chlorobenzoic acid)-
benzoatopropionate with 1-octadecanol in presence of a
suitable catalyst, in dry organic solvent under inert
atmosphere, stirring the reaction mixture initially at
room temperature for 4 hours, refluxing the reaction
mixture for a period upto 22 hours, removing the excess
organic: solvent by vacuum distillation, wasting the
product with suitable cold solvent, drying the product
over an appropriate desiccant for a period of 12 hours,separating the compound by column chroma tog raphy using a silica gel column and appropriate eluent mixlure.
According to another feature of the present invention, the inert, atmosphere may be maintained by using nitrogen.
According to yet another feature of the present invention, the catalyst used is snrh as t r i e t h y 1 a m i. n e.
According to yet another feature of the present invention, the dry organic solvent used is such as dichloromethane, benzene, methanol, dimethylformamide, diethylather.
According to yet another feature of the present invention, organic solvent used for purification of compound by column chromatography is such as acetone, acetonitrile, petroleum ether, dichloromethane.
According to yet another feature of the present invention, drying agent used is such as sodium sulphate, phosphorous pentoxide, calcium chloride.
A step wise process for the preparation of a. room temperature feiroelectric liquid nyslil cimpound,
(s)-2-cliloro-3-(4-beiizmnidoacctophenyl)-l-('4>-odaidccyloxybeuzoyl)-bcrizoato rpioiate, is
presented as follows :
Step 1
(S)-2-amino-3-(4-hydroxyphenyl)-propionic acid - (S)-2-cliloro-3-(4-
hydroxyplicnyl) puipioinic acid
(S)-2-chioro-3-(4-hydroxyphenyl)-propionic acid was prepared by a known method and is descibed frst. 5.43 gram (30.0 minol) of (S)-2-aniuo-3-(4-hydroxyphetiyI)-propionic acid WAS dissolved in 20 ml of 6.0 N IIC1 and the solution was brought to 0 °C. 2.72 gram (32.0 mmol) of fiesily pulverised sodium nitrate was added to the solution in small portions with vigorous stiiring while maintining the reaction temperature between 0 and 5 °C. The reaction mixture was stirred for 16 li. The solution was then extracted with 40 ml of diethylether and the etherinl layer was dried over anhydrous sodium sulphate for 12 h. (S)-2-chioro-3-(4-hydroxyphenyl)-propionic acid obtained as an yellow product on removing the excess solvent by distillation under reduced pressure was repeatedly with cold benzene,
• • r ' '
separated by cliromatography through a silica gel column using a mixture of diethyldhcr : acetone (5:1 v/v) as eluent. The product was recrystallized J5*om hot dichloromethane and dried over p2O-, for 12 h. to get an yield of 3.2 gram (53.2 %).
Step 2
2-benzamidoacetic acid l-chloro-2-benznniidoacetic aeid
l-chloro-2-benzanmidoacetic acid was prepared by mixing togetlier 4.48 gram (25.0 mmol) of 2-benzamidoacetic acid and 3.0 ml (40.0 mmol) of thionyl chloride in 40 ml of dry benzcnc under nitrogen atmosphere and kept the reaction mixture under reflux with continuous stirring at 75 °C for 8 h. After the evalution of SO2 gas was ceased, the volume of the resulting solution was reduced by vacuum distillation to get an yellow solid product which was suction filtered., washed several times witll Cold methanol and dried over anhydrous calcium chloride for 10 h. The product was purified by passing tlirough a silica gel column using a mixlue of petroleum ether : acetonitrile (5 : I v/v) as eluent to get 2.6 gram (52.6 %) of l-chloro-2-benzarnitbacclie acid.
Step 3
l-chloro-2-benzamidoacetic acid I (S)-2-chloro-3-(4-hydroxyphenyl)-pro|pkmic acid
(S)-2-chloro-3-('1-bon?.;mii(loace(ophenyl)-propionic acid
3.95 gram (20.0 mniol) of l-chloro-2-ben/.amidoacetie acid prepared as iiluslialed in slop 2 and 5.0 gram. (25.0 rranol) of (S)-2-chloro-3-(4-hydroxyphenyI)-propionic acid prepared ;is described in step 1 were magnetically stirred in 40 ml dry dichloromefhane at ambient tomporalm •• lot!. n 5 ml ( >. (S)-2-chloro-3-(4-beri7'.ajaidoacctophcnyl)-propionic acid --
(S)-l,2-dicliloro-
3-('1-be»2aiiiidoaceto]iiicnyl)-]ii opionic acid
(o)-],2-dichloro-3-(4-ben/amidoacetoplier,yS)-propionie acid was prepared by dn;olving 5.84 jiram (16.2 niinol) of (S)-2-chloro-3-(4-berizajnidoacetophenyl)-propionic acid prepaied as illustrated in stop 3 in 40 ml of absolute dichlorometlmne and to it added 2.5 ml (21.2 nuuol) of thionylchloride witii constant stirring. 'Hie reaction miturc was- then healed to 60 °C and the stin inu, \vas continued till the evalution of SO^ ceased. On cooling the reaction mixture to room temperature (S)-l,2-dichloro-3-(4-ben/,ajnidoaccU>phcnyl)-propionic acid wan separated as a white solid which was filtered oil' and washed several times with cold chloroform and die final product was recryslalli/ed fiom hot benzene solution. 'Hie product was further purified by column cliromatogliaphy through a silica gel column using a mixture of petroleum ether and acetone in 5 : 1 v/v as eluent to get 4 . 22 gr am (68.84 %) of (S)-l,2-dichloro-3-(4-benzamidoacetophcnyl)-propionic acid.
Step 5
(S)-l)2-dichloro-3-(4-bcnzunidoacetophenyI)-propionic acid + 4-hydroxybenzoic acid
—~ (S)-2-chloro-3-(4-bcnzanidoacolophejiyl)-l-benzoic ncid-propionnle
(S)-2-chloro-3-(4-benzamidoacetophenyl)-l-bonzoic acid-propionate prepared by mixing together absolute dichloromethane solutions of (S)-l,2-dichloro-3-(4-benzamidoacetophenyl) propionic acid (4.81 gram/12.7 mmol in 20 ml of dry dichloromethane) prepared as described in slop 4 and 4-hydroxybenzoic acid (1.8 gram/13.0 mmol in 20 ml of dry dichloromethane) in eqnimobir ratio and the read ion mixture was stirred Ibr4 h at room temperature. 0.4 ml (3.1 mmol) of triotliylumine was then added to the reaction mixture drop wise with constant stirring. The reaction mixture was- (hen refluxed at 75 °C for 18 h. The yellow coloured solulion containing (S)-2-chloro-3-(4-benzmidoacetophenyl 1-benzoic acid-propionate was reduced by vacuum distillation and the product was washed repeatedly with cold acetonitrile solution. The product was separated by column chronafoghaphy through a silica gel column using a mixture of petroleum ether and acetonitrile in 5 : 1 v/v as eliient. The yield obtained was 3.74 gram (63.17 %).
Step 6
(S)-2-chloro-3-(4-benzamidoacelophenyl)-l-benzoic acid propionate
3-(4-be!i2amidoacctophenyl)-l-(l-chlorobonzoic aud)-propionate
(S)-2-chloro-3-(4-beiizamidoacetophenyl)-l-(l-chioro-beiizoic acid)-propionnle was prepared by disolving 3.32g(7.11 mmol) of (S)-2-chloro-3-(4-bcnzainidoacetophenyl)-l-benzoic acid-propionate prepai-ed as descibed in step 5 in 40 ml of absolute dicliloromethane and to it added 0.76 nil (10.4 mmol) of thionylchloride with constant stirring under nitrogen atmosphere. The reaction mixture was then heated to 60 °C and the stirring wan continued till the evolution of SO; ceased On cooling the reaction mixture to room temperature (S)-2-chloro-3-(4-benzamidoacetophonyl)-1-(i-chlorobenzoic acid)-propionate was separated as a white- product which, was filtered off and washed repeatedly with cold chloroform and the product was purified by passing through a silica gel column using a mixture of petroleum ether and acetonitrile in 5 : 1 v/v as eluent. The final product was reciyslnlli/ed from hot benzene solution' to get 1.86 gram (52.32 %) of (S)-2-chloro-3-(4-ben7,aniidoacelophenyl)-i-(l-chlorobenzoic acid)-propionate
Step 7 (S)-2-diloro-3-(4-benzanmioacetophenyl)-l -(l-chlorobcnzoie acid)-propiona!e i -1 • liydi oxybcenzoic
acid (S)-2-chloro-3- (4-benzamidoacetophenyl)-l-(4'-benz.oic acul)-
benzoatopropionatc
(S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-benzoic acid)- benzoatopropionafo was prepared by mixing together absolute dichloromethane solutions of (S)-2-chloro-3-(4-ben:-"»iiidoacetophenyl)-l-(l-chlorobenzoic acid)-propionate (2.65 gram/5.3 mmol in 20 ml dry dichloromethano) prepared as illustrated in step 6 and 4-hydroxybenzoic acid (0.95 gram/68 mmol in 15 ml of dry didiloromethanc) and the reaction mixture was stirred at ambient temperature! for 4 h under nitrogen atmosphere. 0.45 ml (3.2 nrunol) of triethylamine was then added to the reaction mixture drop wise and rclluxed the reaction mixture at 75 °C will) constant stirring for 22 h. The yellow coloured solid of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-benzoic acid)-bcnzoatopropionate was separated by removing the excess solvent by vacuum distillation, washed twice with cold ethanol ami chromatogrnphed through a silica gel column using a mixture of petroleum ether : acetone (5 : 1 v/v) as cluciit. 'the product was reciyslallized from hot benzene solution. The yield obtained was 1.64 gram (51.-18 %).
Step 8
(S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-benzoic acid)-benzoatopropionak* ' (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-l-chlorobenzoic acid)-bcnzoatopropionatae
(S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4>-l-chlorobenzoic acid)-benz.onlopnopionatc was prepared by disolving 2.08 gram (3.3 mmol) of (S)-2-chloro-3-(4-benzamidoactophenyl)-l-(4'-benzoic acid)-ben2oalopropionate prepared • as described in step 7 in '10 ml of absolute dichloromelhane and to it added 0.65 ml (4.7 mmol) of thionylchloride with constant stiiring under nitrogen atmofsphere. The reaction miture was then heated to 00 °C and the stiwting WAS continued till the evalnlion of S02 ceased. On cooling the reaction mixture to room temperature (,S)-2-chloro-3-(4-beii2aniidoacelophenyl)-l-(f'-l-chlorobenzoic acid)-benz:oatopropionate was neparaled as a while colour product which was filtered off, washed repeatedly with cold chloroform and dt ied over vacuo for 12 h. (S)-2-cliloro-3-('}-benzamidoacetophenyl)-l-(4'-l-chlorobcnzoic acid)-benzoaiopropionate was purified by column chromatography through a silica gel colunu) using a mixture ofpolroloum ether : acetone (5 : 1 v/v) as eluent. The product was recrystallized from hot dichloromethanesolution to get an yield of 1.13 gram (52.64 %).
(S)-2-cl]loro-3-(4-beiizaii)idoacetoph€!nyI)-l-(4'-octadecyloxybenzoyl)-ben?:o;ilo|)ropi()nafo was
prepared by mixing together absolute dichloromelhane solutions of (S)-2-chIoro-3-('l-benzamdoacetOphenyl)-l-(4'-l-chlorobcnzoic acid)-benzoatopropio- note (2.0 grnjn/3.2 niniol in 20 ml ol'diy dichloromelhane) synthesized as illustrated in step 8 and 1-octadccaiiol (1.16 grnni/4.3 nunul in 20 ml of dry dichloromcthane) under nitrogen atmosphere and the read ion mixlinv was nlirrcd nt ambient temperature for 4 h. After the addilion of 0.5ml (3.6 mniol) of litieflylaninehyliuiiiiK' Hie ronclion mixlure was reiluxed at 65 °C wthe costant stiring 22 h. the resultaiit solution containing (S)-2-chloro-3-(4-ben2amidoacetophenyl)-l-(4'-octadecyloxybcnzoyl)-benzoaloproi)i011:1(0 \vas reduced to get a bright red geily product and was washed repeatedly with a cold chloroform, the crude product afler drying over yacuuo for 12 h was purified by a silica gel column using a mixture of petrolctuu ether : acetone (5 : 1 v/v) as cluent.the yield obtained was 1.26 gram (45.73 %).ADVANTAGES
The room temperature ferroelectric liquid crystal compound prepared as per the process of this
invention which shows characteristic ferroelectric properties in an around room temperatures which is a
rare phenomena, as the most of the reported •ferroelectric compounds used for the applicational
purposes are the mixtures of more than one component.
The room temperature ferroelectric: liquid crystal compound prepared as per the process of this invention is the refore use fu1 for both fun d amental a s well as applied reseairch aspects including for the nonlinear optical applications.
The room temperature ferroelectric liquid crystal compound prepared as per the process of this invention can further be used as host material's for the preparation of other FLC mixtures.
The need for this type of room temperature ferroelectric materials as strongly felt because the
preparation and characterization of FLC maxtures is time consuming as well as expensive. These? compounds prepared as per the process of this invention can be directly used in the applicantional aspects such as polarisation controllers, switching attenuators' display devices etc.
The study of the fundamental ferroelectric properties viz, spontaneous polarization, tilt angle, time response etc. of the present invented compound reveals that the magnitudes of these parameters are found to be of in good agreement with those of commercially available multi-component materials. In fact some of the above proper-ties envisage that. this compound showed better physical characteristics then the commercially available compounds.

WE CLAIM;
1. A process for the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl) -1- (4'-octadecyloxybenzoyl) benzoatopropionate which comprises in the step of:
i) a first step of preparation of (S)-2-chloro-3- (4-hydroxyphenyl)-propionic acid by nucleophilic substitution of -NH2 group from (S)-2-amino-3- (4-hydroxyphenyl)-propionic acid by a chlorine atom via diazonium salt formation, in the presence of pulverized sodium nitrate,
ii) a second step of preparation of l-chloro-2-benzamidoacetic acid by refluxing as herein described 2-benzamidoacetic acid with thionyl chloride,
iii) a third step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid which comprises in reacting (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid with l-chloro-2-benzamidoacetic acid in presence of a catalyst triethylamme in dry organic solvent selected from dichloromethane, benzene, methonal, dimethyl for manide, diethylether under inert atmosphere of nitrogen;iv) a fourth step of preparation of (S)-l, 2-dichloro-3- (4-benzamidoacetophenyl)-propionic which comprises in refluxing (S)-2-chloro-3-(4-benzamidoacetophenyl-propionic acid with thionyl chloride;
v) a fifth step of preparation (S)-2-chloro-3- (4-benzamidoacetophenyl)-l-benzoic acid propionate by reacting (S)- l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid with 4-hydroxybenzoic acid in presence of said catalyst, in said dry organic solvent under inert atmosphere;
vi) a sixth step of preparation of (S)-2-chloro-3- (4-benzamidoacetophenyl)-l-(l-chlorobenzoic acid) propionate which comprises in reacting (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acid propionate with thionyl chloride,
vii) a seventh step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl) -1 - (4 '-benzoic acid) -benzoatopropionate by reacting (S)-2-chloro-3-(4-benzamidoacetophenyl)-1 -(1 -chlorobenzoic acid) with 4-hydroxybenzoic acid in presence of said catalyst, in said dry organic solvent under inert atmosphere,
viii) an eighth step of preparation (S)-2-chloro-3- (4-
benzamidoacetophenyl)-l-(4' -1—chlorobenzoic acid)-
benzoatopropionate which comprises in reacting (S)-2-chloro-3-
(4-benzamidoacetophenyl)-l-4'- benzoic acid)-
benzoatopropionate with thionyl chloride,
ix) a ninth step of preparation of (S)-2-chloro-3- (4-
benzamidoacetophenyl)-l-(4'-octadecyloxybenzoyl)-
benzoatopropionate which comprises in reacting (S)-2-chloro-3-
(4-benzamidoacetophenyl)-1-(4'-1-chlorobenzoic acid)-
benoatopropionate with 1-octadecanol in presence of said catalyst, in said dry organic solvent under inert atmosphere.
2. A process as claimed in claim 1 wherein said first step comprises in nucleophilic substitution of -NHa group from (S)-2-amino-3- (4-hydroxyphenylj-propionic acid by a chlorine atom via diazonium salt formation, in the presence of freshly pulverised sodium nitrate, stirring the reaction mixture at 0-4°C, extracting with organic solvent selected from acetone, acetonitrite, petroleum ether, dichloromethane, drying the organic layer with a drying agent selected from sodium sulphate, phosphorous pentoxide, calcium chloride, removing the excess solvent
under reduced pressure, separating the compound by column chromatography using a silica gel column and a mixture of diethylether and acetone, followed by recrystallization to get crystals of (S)-2-chloro-3-(4-hydrooxpheny 1)-propionic acid.
3. A process as claimed in claim 1 wherein said second step comprises the preparation of l-chloro-2-benzamidoacetic acid by refluxing 2-benzamidoacetic acid with thionyl chloride at 75°C, removing said excess organic solvent by vacuum distillation, washing the product with cold solvent which is methonal, drying the product over drying agents selected from sodium sulphate, phosphorous pentoxide, calcium chloride and a mixture of petroleum ether and acetonitrile.
4. A process as claimed in claim 1 wherein said third step comprises the preparation of (S)-2-chloro-3- (4-benzamidoacetaphenyl)-lpropionic acid by reacting (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid with l-chloro-2-benzamidoacetic acid in presence of said catalyst in said dry organic solvent under inert atmosphere stirring the reaction mixture initially at room temperature, refluxing the reaction mixture for 12 hours, over P2Os, separating the compound by column chromatography using a silica
gel column and appropriate eluent mixture of diethyl ether and acetone followed by recrystallization to get crystals of (S)-2-chloro-3-{4-benzamidoacetophenyl) -propionic acid.
5. A process as claimed in claim 1 wherein said fourth step comprises
the preparation of (S)-l,2-dichloro-3- (4-benzamidoacetophenyl)-
propionic acid by refluxing (S)-2-chloro-s-(4-benzamidoacetophenyl)-
propionic acid with thionyl chloride with constant stirring, removing
the excess organic solvent by vacuum distillation, washing the
product with said cold solvent, drying the product over said desiccant,
separating the compound by column chromatography using a silica
gel column and appropriate eluent mixture comprising petroleum
ether and acetone, followed by recrystallization to get crystals of (S)-l-
2-dichloro-3 (4-benzamidoacetophenyl)lpropionic acid.
6. A process as claimed in claim 1 wherein said fifth step comprises the
preparation of (S)-2-chloro-3- (4-benzamidoacetophenyl)l-bezonic acid
propionate by reacting (S)-l-, 2-dichloro-3-(4-
benzamidozcetonphenyl)-propionic acid with 4-hydroxybenzoic acid in
presence of said catalyst, in said dry organic solvent under inert
atmosphere, stirring the reaction
mixture initially at room temperature, refluxing the reaction mixture, removing the excess organic solvent by vacuum distillation, washing the product with said cold solvent, drying the product over said desiccant, separating the compound by column chromatography using silica gel column and appropriate eluent mixture comprising petroleum ether and acetonitirle.
7. A process as claimed in claim 1 wherein said sixth step comprises the
preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)l-(l-
chlorobenzonic acid) propionate by reacting (S)-2-chloro-3-(4-
benzamidoacetophenyl)-l-benzoic acid propionate with thionyl
chloride with constant stirring, removing the excess organic solvent by
vacuum distillation washing the product with said cold solvent, drying
the product over said desiccant, separating the compound by column
chromatography using a silica gel column and appropriate eluent
mixture comprising petroleum ether and acetonitrile followed by
recrystallization to get crystal (s)-2-chloro-3-(4-behzamidoacetopheyl)-
l-(l-chlorobenzoic acid) propionate.
8. A process as claimed in claim 1 wherein seventh step comprises the
preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-benzoic
acid) benzoato-propionate by reacting (S)-2-chloro-3-(4-
benzamidoacetophenyl)-l-(l-chlorobenzoic acid) propionate with 4-hydroxybenzoic acid in presence of said catalyst, in said dry organic solvent under inert atmosphere, stirring the reaction mixture initially at room temperature, refluxing the reaction mixture, removing the excess organic solvent by vacuum distillation, washing the product with said cold solvent, drying the product over said desiccant, separating the compound by column chromatography using a silica gel column and appropriate eluent mixture comprising petroleum and acetone.
9. A process as claimed in claim 1 wherein said eight step comprises the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-l-chlorobenzoic acid) benzaotopropionate by reacting (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4' benzoic acid)-benzamidoacetophenyl) with thionyl chloride with constant stirring, removing the excess organic solvent by vacuum distillation, washing the product with said cold solvent, drying the product over said desiccant, separating the compound by column chromatography using a silica gel column and appropriate eluent mixture comprising petroleum ether and acetone.
10. A process as claimed in claim 1 wherein ninth step comprises the
preparation of (S)-2-chloro-3-(4-benzamido-acetophnyl)-l-(4'-
octadecyloxybenzoyl-benzoatopropionate) by reacting (S)-2-chloro-3-
(4-benzamidozcetophenyl)-1 -4'-1 -chlorobenzoic acidj-
benzoatopropionate with 1-octadeconal in presence of said catalyst in said dry organic solvent under inert atmosphere, stirring the reaction mixture initially at room temperature, refluxing the reaction mixture for a period, removing the excess organic solvent by vacuum distillation washing the product with said cold solvent, drying the product over said desiccant, separating the compound by column chromatography using a silicon gel column and appropriate eluent mixture of petroleum ether and acetone.
11. A process for the preparation for the preparation of (S)-2-chloro-3-
(4-benzamidoacetophenyl)-1-(4' -octoadecyloxybenzoyl)-
benxoatopropionate, substantially as herein describes and exemplified in the example.

Documents:

944-del-1998-abstract.pdf

944-del-1998-claims.pdf

944-del-1998-correspondence-others.pdf

944-del-1998-correspondence-po.pdf

944-del-1998-description (complete).pdf

944-del-1998-drawings.pdf

944-del-1998-form-1.pdf

944-del-1998-form-19.pdf

944-del-1998-form-2.pdf

944-del-1998-form-3.pdf

944-del-1998-gpa.pdf

944-del-1998-petition-other.pdf

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Patent Number

220192

Indian Patent Application Number

944/DEL/1998

PG Journal Number

28/2008

Publication Date

11-Jul-2008

Grant Date

16-May-2008

Date of Filing

15-Apr-1998

Name of Patentee

THE SECRETARY, DEPARTMENT OF ELECTRONICS

Applicant Address

Inventors:

#	Inventor's Name	Inventor's Address
1	VENKATA GOPALAKRISHNA MURTHY, PISIPATI
2	ANJANA KUMAR, POLURI

PCT International Classification Number

F02F 1/33

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA