Title of Invention	"A PROCESS FOR PREPARATION OF A NOVEL ROOM TEMPRETURE FERROELECTRIC (LIQUID) CRYSTAL COMPOUND (S)-2-CHLORO-3-(4-BENZAMIDOACETOPHENYL)-1-(4'-DODECYLOXYBENZOYL)-BENZOATOPROPIONATE"
Abstract	A process for the preparation of a novel room temperature ferroelectric liquid crystal compound (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4"- dodecyloxybenzoyl)-benzoatopropionate which comprises in the step of: a first step of 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 freshly pulverized sodium nitrate to obtain crystals of (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid; a second step of preparation of l-chloro-2-benzamidoacetic acid by refluxing 2- benzamidoacetic acid with thionyl chloride; a third step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid which by reacting (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid with l-chloro-2- benzamidoacetic acid in presence of a catalyst and in dry organic solvent under inert atmosphere; a fourth step of preparation of (S)-l, 2-dichloro- 3-(4-benzamidoacetophenyl)-propionic acid by refluxing (S)-2-chloro-3-(4- benzamidoacetophenyl-propionic acid with thionyl chloride; a fifth step of preparation (S)-2-chloro-3-(4-benzamidoacetophenyl)- 1-benzoic acid propionate by reacting (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)- propionic acid with 4-hydroxybenzole acid in presence of a catalyst and dry organic solvent under inert atmosphere;

Title of Invention

"A PROCESS FOR PREPARATION OF A NOVEL ROOM TEMPRETURE FERROELECTRIC (LIQUID) CRYSTAL COMPOUND (S)-2-CHLORO-3-(4-BENZAMIDOACETOPHENYL)-1-(4'-DODECYLOXYBENZOYL)-BENZOATOPROPIONATE"

Abstract

A process for the preparation of a novel room temperature ferroelectric liquid crystal compound (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4"- dodecyloxybenzoyl)-benzoatopropionate which comprises in the step of: a first step of 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 freshly pulverized sodium nitrate to obtain crystals of (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid; a second step of preparation of l-chloro-2-benzamidoacetic acid by refluxing 2- benzamidoacetic acid with thionyl chloride; a third step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid which by reacting (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid with l-chloro-2- benzamidoacetic acid in presence of a catalyst and in dry organic solvent under inert atmosphere; a fourth step of preparation of (S)-l, 2-dichloro- 3-(4-benzamidoacetophenyl)-propionic acid by refluxing (S)-2-chloro-3-(4- benzamidoacetophenyl-propionic acid with thionyl chloride; a fifth step of preparation (S)-2-chloro-3-(4-benzamidoacetophenyl)- 1-benzoic acid propionate by reacting (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)- propionic acid with 4-hydroxybenzole acid in presence of a catalyst and dry organic solvent under inert atmosphere;

Full Text	This invention relates to a novel room temperature ferroelectric liquid crystal compound, (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4-dodecyloxybenzoyl)-benzoatopropionate having the formula as shown in Pig. 1 of the accompanying drawings and to a process for the preparation thereof. The compound is a novel room temperature ferroelectric liquid crystal (FLC) which is useful in the applicational aspects such as polarization controllers, switching attenuators and display devices. PRIOR ART Hitherto there are no processes of synthesizing these room temperature ferroelectric compounds made out of optically active (S)-2-amino-3-(4-lrydroxyphenyl)-propionic acid. THENVENTION The mam 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)- 1 -(4'-dodecyloxybenzoyl)- benzoatopropionate, which exhibits ferroelectricity at ambient temperature. DESCRIPTION OF THE INVENTION According to the invention there is provided a process for the preparation of a novel room temperature ferroelectric liquid crystal compound,(S)--2-chloro--3-(4-benzamidoacetophenyl)-l-(4'-dodocyloxybcnzoyl) benzoatopropionate which comprises in the step of: i) a first step of nucleophilic substitution of - ' from (S)-2-ami no-3- (4-hydroxyphenyl) -propioni c acid by a chlorine atom via diazonium salt formation, in the presence of freshly pulverized sodium nitrate to obtain crystal of (S) -2-chloro-3-(4-hydroxyphenyl ) -propionic acid; ii) a second step of preparation of l-chloro-2- benzamidoacetic acid by refluxing 2-benzamidoacetic acid with thionyl chloride; iii) a third step of preparation of (6)-2-chlaro-3-(4- benz ami doacet aphony 1 ) -propionic acid which by reacting (S)-2- chl or 0-3- (4-hydr oxyphenyl ) -propionic acid with i-chloro— 2- benz ami doacet i c acid in presence of a catalyst and in dry organic solvent under inert atmosphere; iv) a fourth step of preparation of (3)— 1 ,2— dichl oro-3-(4— benz ami doacetophenyl ) -propionic acid by refluxing (S)— 2- chloro-3-(4-benzamidoacetophenyl -propionic acid with thionyl chloride. v) a fifth step of preparation of (S)-2-chloro-3-(4- benzamidoacetophenyl )-l-benzoic acid propi onate by reacting (S)-l ,2-dichlor o-3- (4-benz ami doacet ophenyl) -propionic acid with 4-hydroxybenzoic acid in presence of a catalyst and dry organic solvent under inert atmosphere} vi ) a sixth step of preparation of (S)-2-chloro— 3-(4- benzaroidoacetophenyl)-l— (1-chlorobenzoic acid) propi onate by reacting (S) -2-chloro-3-(4-benzamidoacetoph«nyl )-l-benoic acid propi onate with thionyl chloride; vii) a seventh step of preparation of (S)-2-chloro-3-(4- benzaroidoacet ophenyl)-1-(4'-benzole acid)-benzoatoproPionate by reacting (S)-2-chloro-3-(4-benzamidoacetophcnyl)-l-(l-chlorotaenzoic acid) propionate with 4-hydroxyben7oic acid in presence of a catalyst and dry organic solvent under inert atmosphere; viii) a eighth step of preparation of (S)-2-chloro-3-(4- benzamido-actophenyl)-1-(4'-l-chlorobenzoic acid)- benzoatopropinnate by reacting (S) -2-chloro-3-(4- benzamidoacetopheny1)-l-(4'-benzoic acid)-benzoatapropionate with thionyl chloride); ix) a nineth step of preparation of (S)—2-chlaro-3-(4- benz ami do—acei opheny 1 ) -1 -- ( 4 ' -dodecy1 ax ybenzoy 1 ) -benz oatapr opi onat e by reacting (S)-2-chloro—3—(4—benzamidoacetophenyl)—1—(4'— l-chlorobenzoic acid)-benzoatopropionate with 1-dodecanol in presence of a catalyst and dry organic solvent under inert atmosphere. According to the present invention, preparation o-f this material comprises a total of nine steps followed by various compositions under different conditions. Thp first step comprises the process of nucleophilic substitution of -NH2 group from (S)-2-amino-3- (4-hydroxyphenyi)-propionic acid by a chlorine atom via diazonium salt foroation, in the presence of freshly pulverized sor'; um nitrate, stirring the reaction mixture -for 6 hours at 0 -4°C, extracting with a suitable organic solvent, drying the organic layer with an appropriate drying agent for 12 hours, removing the excess solvent under reduced pressure, separating the compound by column chromatography using a silica gel column and appropriate eluwnt mixture, followed by recrystaliization to get crystals of (S)-2-chloro-3-(A- hydroxyphenyD-propionic acid. Second step of the process illustrates the preparation of I-chloro-2-benzamidoacetic acid by refluxing 2-benzamidoacetic acid with thionyi chloride at 75° C for 8 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 10 hours, separating the compound by column chromatography using a sili' a tjel column and appropriate eluent mixture. Third step of the process describes the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic arid which by reacting (S)-2-chloro—3-(4— hydroxyphenyl )--propionic acid with l-chloro-2— benzamidoacetic acid in presence of a catalyst and 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 chromatography using a silica gal column and appropriate eluent mixture, followed by recrystallizai ion to get crystals of (S)-2-chloro-S-(4-benzatrddoacet fiphenyl) -propionic acid. Fourth step of the process describes the preparation of (S)-1,2-dichloro-3-(4-benzamidoacetopheny1)-propionic acid by refluxing (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic. acid with thionyl chloride with constant stirring, removing the excess organic solvent by vacuum distillation, washing the product with suitable cold solvent. Fifth step of the process describes the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l— benzoic acid prapionate by reacting (S)-i,2—dichloro—3—(4— benzaroidoacetophenyl) -propionic acid with 4—hyclr oxybenzoic acid in preservence oi A catalyst and dry organic solvent und»r inert atmosphere,stirring the reaction mixture initially at room temperature for 4 hours, refluxing the reaction mixture for a periori upto 18 hours, removing the excess organic solvent by vacuum distillation, washing the product with suitable colri -olvent, 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 p1. uent mixture. Sixih step of the process describes the preparation of (S)—2-chlnro—3-(4-benzamidoacetophenyI)-1—(1- chlorobenzoic acid) propionate by reacting (S)-2-chl benzamidoacetaphenyl)-1-benzoic acid propionate with thionyl chloride with constant stirring, removing the excess organic solvent by vacuum distillation, washing th? 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 and appropriate eluent mixture, followed by recrystalii ration to get crystals of (S)-2-chloro-3-(4-benzamidoacetophenyD-l-d-chlorobensoic acid) propionate. Seventh step of the process describes the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-benzoic acidl-benzoatopropianate by reacting (S)-2-chloro-3— (4-benzamidocetophenyl)-l-(1-chlorobenzoic acid) propionate with 4-hydrnxybenzoic acid in presence o-f a catalyst and dry organic -solvent under inert atmosphere, stirring the reaction mixture initially at room temperature for 4 hours,refluxing the reaction mixture for & period upto 22 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. Eigtith step of the process describee the preparation of (S)-2-chlaro-3-(4-benzamidoacetophenyl)-l-(4'-l- chlorobenzoi r acid) -benzctatopropionate by reacting (S)-2- chloro-3-(4-bn7.amidoacetophenyl)-i-(4'-benzole cid)- henzoatoprap)onate with thionyl chloride 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 12 hours, separating the compound by column chromatography iming a si lira gel column and appropriate eluent mixture. Ninpth step o-f the process describes the preparation of (S)-2-chloro-3-(4-benzamido-acetophenyl)-l-(4'-dodecyl oxybenroyl )-benzoatopropionate by reacting (S)-2-chloro-3— (4 t(r-r7 amidoacetophenyl ) -1- (4 '—1—chlorobnzoi c aci d)-benzoatopropionate with 1-dodecanol in prrence of a ratalyst anrl dry organic solvent under inert atmosphere, stirring the reaction mixture initially at room tpmperature for ft hours, refluxing the reaction mixture for a period upto 16 hoursT rr'mdving the excess organic solvent by vacuum distillationt washing the product with suitable cold solvent, separating HIP compound by column chromatography using silica gel col \(mn and appropriate eluent mixture. Acrording to another feature of the present invention, the inert atmosphere may be maintained by using ni trogen. Acrrjrding to yet another feature of the prevent. invention, thr- catalyst used is such as tr i ethyl ami ne. According to yet another feature o-f the present invention, the dry organic solvent used is such as dichloromethanp, benzene, methanol, dimethylformamide, diethylether. According to yet another feature of the present invention, organic solvent used far purification of compound by column chromatography is such as actone, actonitrilT petroleum ether, dichloromethane. According to yet another feature of the present invention, crying agent used is such as Kodium eulphate, phosphorous pp'ntoxide, calcium chloride. A stpp wise process for the preparation of a room temperature 4e)rroelectric liquid crystal cowpound, (8)-2-chloro-3-(4-bfenzanudoacetophenyI )-i-(4'-dodecyloxybenzoyl )-benzoatopropi ornate, is presented as follovi (S)-2-amino-3-(4-hydroxyphenyl)-propionic acid (S)-2- chloro-3-(4-hydroxyphenyl)-propionic acid (S)-2-chloro-3-(4-hydroxyphenyl)-prop)onic acid was prepared by a known method and is described first 5.43 gram (30.0 mmol) of (S)-2-amino-3-(4-hydroxyphenyl)-propionic acid was dissolved in 20 ml of 6.0 N HCI and the solution was brought to 0°C. 2.72 gram (32.0 mmol) of freshly pulverised sodium nitrate was added to the solution in small portions with vigorous stirring while maintaining the reaction temperature between 0 and 5°C. The reaction mixture was stirred for 16 h. The solution was then extracted with 40 ml of diethylether and the etherial layer was dried over anhydrous sodium sulphate for 12 h. (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid obtained as an yellow product on removing the excess solvent by distillation under reduced pressure was washed repeatedly with cold benzene, seperated by chromatography through a silica gel column using a mixture of diethylether : acetone (5:1 v/v) as eluent. The product was recrystallized from hot dichlorornethane and dried over P2O5 for 12 h. to get an yield of 3.2 gram (53.2%). Step 2 2-benzamidoacetic acid l-chloro-2-benzamidoacetic acid l-chloro-2-benzamidoacetic acid was prepared by mixing together 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 benzene 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 of get an yellow solid product which was suction filtered, washed several times with cold methanol and dried over anhydrous calcium chloride for l0h. The product was purified by passing through a silica gel column using a mixture of petroleum ether: acetonitrile (5:1 v/v) as eluent to get 2.6 gram (52.6%) of l-chloro-2-benzamidoacetic acid. l-chloro-2-benzamidoacetic acid + (S)-2-chloro-3-(4-hydroxyphenyl)- propionic acid (S)-2-chloro-3-(4-benzamidoacetophenyl)- propionic acid 3.95 (20.0 mmol) of l-chloro-2-benzamidoacetic acid prepared as illustrated in step 2 and 5.0 gram. (25.0 mmol) of (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid prepared as described in step 1 were magnetically stirred in 40 ml dry dichloromethane at ambient temperature for 2 h. 0.5 ml (3,6 mmol) of triethylamine was then added to the reaction mixture drop wise and the reaction mixture was refluxed at 60°C with constant stirring for 12 h. The yellow coloured (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid obtained on cooling the reaction mixture to room temperature was filtered off, washed repeatedly with cold methanol and recrystallised from hot acetone and dried over P2O5 for 12 h. The resultant product was further purified by chromatography through a silica gel column using a mixture of diethylether: acetone (5:1 v/v) as eluent to get an yield of 2.81 gram (69.82%). Step 4 (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid (S)- 1,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid was prepared by dissolving 5.84 gram (16.2 mmol) of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid prepared as illustrated in step 3 in 40 ml of absolute dichloromethane and to it added 2.5 ml (21.2 mmol) of thionylchloride with constant stirring. The reaction mixture was then heated to 60°C and the stirring was continued till the evalution SO2 ceased. On cooling the reaction mixture to room temperature (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid was separated as a white solid which was filtered off and washed several times with cold chloroform and the final product was recrystallized from hot benzene solution. The product was further purified by column chromatography through a silica gel column using a mixture of petroleum ether and acetone in 5:1 v/v as eluent to get 4.22 gram (68-84%) of (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid. : 12 : StcpS (S)-l,2-dichloro-3-(4-beny.amidoacetopheriyl)-propionic acid + 4-hydroxybenzoic acid (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acid-piopionale (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acidpropionate prepared by mixing together absolute dichloromethane .solutions of (S)-l(2-dichloro-3-(4-ben2amidoacetophenyl)-propionic acid (4.81 gram/12.7 mmol in 20 ml of dry dichloromelliane) prepared as described in step 4 and 4-hydroxybenzoic acid (1.8 gr am/13.0 nunol in 20 ml of dry dichlorometliane) in equimolar ratio and the reaction mixture was stirred for 4 h at room temperature. 0.4 ml (3.1 mmol) of trielhylamine was then added to the reaction mixtuie drop wise with constant sliming. 'the reaction mixture was then relluxed t at 75 °C for 18 h. The yellow coloured solution containing (S)-2-chloro-3-(4-benzamidoacetophenyl)-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 chromatoghaphy through a silica gel column using a mixture of petroleum ether and acetonitrile in 5 : 1 v/v as eluent. The yield obtained was 3.74 gram (63.17 %). Step 6 (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acidpropionate (S)-2-chloro- 3-(4-benzamidoacetophenyl)-l-(l-chloro-benzoic acid)-propionate (S)-2-chloro-3-(4-beiizamidoacetophenyl)-l-(l-chloro-bc.nzoic acid)-propionate was prepared by disolving 3.32 g (7.11 mrnol) of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acid-propionate prepared as descibed in slop 5 in 40 ml of absolute dichloromethane and to it added 0.76 ml (10.4 mmol) of thionylchloride with constant stirring under nitrogen atmosphere. The reaction mixture was then heated to 60 °C and the stirring was continued till the evalution of SO2 ceased. On cooling the reaction mixture to room temperature (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(l-chloro-beii7.oic 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 reciyslallized from hot benzene solution to get 1.86 gram (52.32 %) of (S)-2-chloro-3-(4-ben/amidoacelophenyl)-l-(l-chlorobenzoic acid)-propionale. Step 7 (S)-2-cliloro-3-(4-benzaloncetoplieiiyl)-l-(l-clilorol)ei-'.oic acid)-propioiinll-hydioxybeii/oic acid (S)-2-chlon)-.)-('1-\|)eii7,aitiidoaceloplienyl)-]-(4'-beii7oii- and)- benzoatopropioiiate (S)-2-chloro-3-(44)en/amidoacetop- add)-ben7,O}ifopropiouale was- prepared by mixing together absolute didiloromelhane solutions of (S)-2-chloro-3-(4-ben7.ainidoacelophenyl)-l- (l-dilorobcnzoic acid)-pioj)ioiiatc (2.65 gram/5.3 mmol in 2.0 nil dry dichloromelhaue) prepared as illustrated in slep 6 and -1 hydroxybcnzoic acid (0.95 gram/68 rnrnol in 15 nil oi'diy didilotoinelhane) and the reaction mixture was stirred at ambient temperature for 4 h under nitrogen almnsphei e. 0.45 nil (3.2 miuol) of'trieliiylaniine was then added lo the reaction mixture drop wise and i ellnxed (he reaction mixture at 75 °C with constant stirring for 22 h. The yellow coloured solid of (S) •?. diloro-.?-(4-l)en:r.!iHiidoacetophcnyl)-l-(4"-benzoic% acid)-benzoatopropionate was separated by removing (lie excess solvent by vacuum distillation, washed twice with cold elhanol and chronialoRiiiphed through a silica gel column using a mixture ol'pelioleum elher : acetone (5 : 1 v/v) as eluent. The product was reciystalli/.ed fi'om hot luMi::eiu) solution. The yield obhnned was 1.64 gram (51.48 "i.). Step 8 (S)-2-cli!(M'o-3-(4-benzamidoacetoplienyI)-l-(4'-beii7,oic acid)-ben/oatopropionate (S)-2-chloro-3-(4-bc(nzainidoacetoplienyl)-l-(4'-l-dilorobcnzoic acid)-l)eii;i.oalopio[)ionate (S)-2-chloro-3-(4-ben)',amidoacetophenyl)-l-(4M-chlorobenzoic acid)-ben/.oalopi()\|'ionate was pre})ared by disolving 2.08 grain (3.3 mmol) of (S)-2-diloro-3-(4-benzmnidoacetop!uMiyl)-1-(4'-benzoic ac%id)-benzoatopiopionate prepared as described in step 7 in 40 ml ol' absolute dichloiomethajie and to if added 0.65 ml (4.7 nimol) of thionylchloride with constant sliiring undei uilrogeu atmosphere. 'J'he reaction niiture wa^ then heated to 60 °C (uid the stirring was continued till the evalution of SO? ceased. On cooling the reaction mixture to room temperature (S)-.?-chloro-3-(4-beu/.amidoacetophenyl)-! (I'-l-chlorobeu/.oic acid)-ben/.oatoj)i opionate was sepaialod as a while colour product which was lilleivd oif, washed repeatedly with cold chloroform and di iod over vacuuq for 12 h. (S)-2-cliloi() 3-(4-ben)'.ajui(loacetophenyl)-l-(4'-l-chlorobenzoic arid)-ben:-,oatopro-pionate was purified by column cinematography through a silica gel column iisma a mixture of petroleum ether : acelonr (5 : 1 v/v) a,s elueut. The product was reoy.';l:tlli:vd from hot dichloromelhane solution to get an yield of 1.13 gram (52.64 %). Step 9 (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-1-chiorobenzoic acid)-benzoatopropionate -» i-dodecanol (S)- 2-chl or 0-3-( 4-benz ami doacirtDphenyl ) -1- (4 '-dodecyloxybenzoyl )- benzoatopropionate (S)-2-chloro-3-(4-benz ami doacetophenyl)-1-(4'- dodecyloxybenzoyl)-benzoatopropionate Mae prepared by stirring together absolute dichloromethane solutions of tS)- 2-chioro-3-(4-benzamidaacetophenyl)-1-(4'—l-chlorobenzoic acid)-benzoatoprapionate (2.1 gran/3.4 mmol in 15 ml of dry dichioromethane) prepared a illustrated in step 8 and 1— dadecanol ((Z.3 gram/4.3 mmol in 15 ml of dry dichloromethane) under nitrogen atmosphere at room temperature nd the reaction mixture Mas stirred for 5 h. 0.5 ml (3.6 mmol) o-f triethyl amine was added to the reaction mixture drop wise and the reaction mixture refluxed at 75°C for 16 h. The yellow coloured solution containing (S)-2-chloro-3-(4- benzamidaacetoph»nyl)-i-(4'-octyloxybenzoyl)- benzoatopropionate was isolated as an yellow golly product after removing the excess solvent by vacuum distillation and the product was; further purified by column chrotwutography through a silica gel column using a mixture Of petroleum etheri acetonitrile (5s 1 v/v) as eluervt to get n yield of 1.33 gram (51-(3".(- ADVANTAGES The room temperature ferroelectric liquid crystal compound .prepared by the process of this -invention )thich 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 applirational purposes are the mixtures of more than one component. The room temperature ferroelectric liquid crystal compound prepared by the process of this invention i» therefore useful for both fundamental as well applied research aspects including for the non-linear optical applications. The room temperature ferroelectric liquid crystal compound can further be used as hat materials for the preparation of other FLC mixtures. The need for this type of room temperature ferroelectric materials aw strongly felt because the preparation and characterization of FLC mixtures is time consuming as well as expensive. These compound* prepared as .per the process of this invention can be 'directly used in the -i applinational aspects such as polarization controller switching attenuators, vdisplay 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 magnitude of these parameters are found to be of in good agreement with those of commercially available compounds. In fact some of the above properties envisage that this compound showed better physical characteristic than the commercially available compound. WE CLAIM: 1. A process for the preparation of a novel room temperature ferroelectric liquid crystal compound (S)-2-chloro-3-(4-benzamidoacetophenyl)-l- (4'-dodecyloxybenzoyl)-benzoatopropionate which comprises in the step of: i) a first step of 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 freshly pulverized sodium nitrate to obtain crystals of (S)-2-chloro-3-(4~ hydroxyphenyl)-propionic acid; ii) a second step of preparation of l-chloro-2-benzamidoacetic acid by refluxing 2-benzamidoacetic acid with thionyl chloride; iii) a third step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid which by reacting (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid with l-chloro-2-benzamidoacetic acid in presence of a catalyst and in dry organic solvent under inert atmosphere; iv) a fourth step of preparation of (S)-l, 2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid by 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 a catalyst and dry organic solvent under inert atmosphere; Step 1 (S)-2-amino-3-(4-hydroxyphenyl)-propionic acid (S)-2- chloro-3-(4-hydroxyphenyl)-propionic acid (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid was prepared by a known method and is described first 5.43 gram (30.0 mmol) of (S)-2-amino-3-(4-hydroxyphenyl)-propionic acid was dissolved in 20 ml of 6.0 N HCI and the solution was brought to 0°C. 2.72 gram (32.0 mmol) of freshly pulverised sodium nitrate was added to the solution in small portions with vigorous stirring while maintaining the reaction temperature between 0 and 5°C. The reaction mixture was stirred for 16 h. The solution was then extracted with 40 ml of diethylether and the etherial layer was dried over anhydrous sodium sulphate for 12 h. (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid obtained as an yellow product on removing the excess solvent by distillation under reduced pressure was washed repeatedly with cold benzene, seperated by chromatography through a silica gel column using a mixture of diethylether : acetone (5:1 v/v) as eluent. The product was recrystallized from hot dichloromethane and dried over P2O5 for 12 h. to get an yield of 3.2 gram (53.2%). Step 2 2-benzamidoacetic acid l-chloro-2-benzamidoacetic acid l-chloro-2-benzamidoacetic acid was prepared by mixing together 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 benzene 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 of get an yellow solid product which was suction filtered, washed several times with cold methanol and dried over anhydrous calcium chloride for l0h. The product was purified by passing through a silica gel column using a mixture of petroleum ether: acetonitrile (5:1 v/v) as eluent to get 2.6 gram (52.6%) of l-chloro-2-benzamidoacetic acid. Step3 l-chloro-2-benzamidoacetic acid + (S)-2-chloro-3-(4-hydroxyphenyl)- propionic acid (S)-2-chloro-3-(4-benzamidoacetophenyl)- propionic acid 3.95 (20.0 mmol) of l-chloro-2-benzamidoacetic acid prepared as illustrated in step 2 and 5.0 gram. (25.0 mmol) of (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid prepared as described in step 1 were magnetically stirred in 40 ml dry dichloromethane at ambient temperature for 2 h. 0.5 ml (3,6 mmol) of triethylamine was then added to the reaction mixture drop wise arid the reaction mixture was refluxed at 60°C with constant stirring for 12 h. The yellow coloured (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid obtained on cooling the reaction mixture to room temperature was filtered off, washed repeatedly with cold methanol and recrystallised from hot acetone and dried over P2O5 for 12 h. The resultant product was further purified by chromatography through a silica gel column using a mixture of diethylether: acetone (5:1 v/v) as eluent to get an yield of 2.81 gram (69.82%). Step 4 (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid (S)- 1,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid was prepared by dissolving 5.84 gram (16.2 mmol) of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid prepared as illustrated in step 3 in 40 ml of absolute dichloromethane and to it added 2.5 ml (21.2 mmol) of thionylchloride with constant stirring. The reaction mixture was then heated to 60°C and the stirring was continued till the evalution SO2 ceased. On cooling the reaction mixture to room temperature (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid was separated as a white solid which was filtered off and washed several times with cold chloroform and the final product was recrystallized from hot benzene solution. The product was further purified by column chromatography through a silica gel column using a mixture of petroleum ether and acetone in 5:1 v/v as eluent to get 4.22 gram (68-84%) of (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid. catalyst and dry organic solvent as herein described 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 a cold solvent, separating the compound by column chromatography using a silica gel column and eluent mixture comprising petroleum ether and acetonitrile. 11. A process for the preparation of a novel room temperature ferroelectric liquid crystal compound, (S)-2-chloro-3-(4- benzamidoacetophenyl)— 1 - (4 '-dodecyloxybenzoyl) -benzoatopropionate, substantially as herein described and exemplified in the examples.

Full Text

This invention relates to a novel room temperature ferroelectric liquid crystal compound, (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4-dodecyloxybenzoyl)-benzoatopropionate having the formula as shown in Pig. 1 of the accompanying drawings and to a process for the preparation
thereof. The compound is a novel room temperature ferroelectric liquid crystal (FLC) which is useful in the applicational aspects such as polarization controllers, switching attenuators and display devices.
PRIOR ART
Hitherto there are no processes of synthesizing these room temperature ferroelectric compounds made out of optically active (S)-2-amino-3-(4-lrydroxyphenyl)-propionic acid.
THENVENTION
The mam 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)- 1 -(4'-dodecyloxybenzoyl)-
benzoatopropionate, which exhibits ferroelectricity at ambient
temperature.
DESCRIPTION OF THE INVENTION
According to the invention there is provided a process for the preparation of a novel room temperature ferroelectric liquid crystal compound,(S)--2-chloro--3-(4-benzamidoacetophenyl)-l-(4'-dodocyloxybcnzoyl) benzoatopropionate which comprises in the step of:
i) a first step of nucleophilic substitution of - '
from (S)-2-ami no-3- (4-hydroxyphenyl) -propioni c acid by a chlorine atom via diazonium salt formation, in the presence
of freshly pulverized sodium nitrate to obtain crystal of (S) -2-chloro-3-(4-hydroxyphenyl ) -propionic acid; ii) a second step of preparation of l-chloro-2-
benzamidoacetic acid by refluxing 2-benzamidoacetic acid with thionyl chloride;
iii) a third step of preparation of (6)-2-chlaro-3-(4-
benz ami doacet aphony 1 ) -propionic acid which by reacting (S)-2-
chl or 0-3- (4-hydr oxyphenyl ) -propionic acid with i-chloro— 2-
benz ami doacet i c acid in presence of a catalyst and in dry
organic solvent under inert atmosphere;
iv) a fourth step of preparation of (3)— 1 ,2— dichl oro-3-(4—
benz ami doacetophenyl ) -propionic acid by refluxing (S)— 2-
chloro-3-(4-benzamidoacetophenyl -propionic acid with thionyl
chloride.
v) a fifth step of preparation of (S)-2-chloro-3-(4-
benzamidoacetophenyl )-l-benzoic acid propi onate by reacting
(S)-l ,2-dichlor o-3- (4-benz ami doacet ophenyl) -propionic acid
with 4-hydroxybenzoic acid in presence of a catalyst and dry
organic solvent under inert atmosphere}
vi ) a sixth step of preparation of (S)-2-chloro— 3-(4-
benzaroidoacetophenyl)-l— (1-chlorobenzoic acid) propi onate by
reacting (S) -2-chloro-3-(4-benzamidoacetoph«nyl )-l-ben*oic
acid propi onate with thionyl chloride;
vii) a seventh step of preparation of (S)-2-chloro-3-(4-
benzaroidoacet ophenyl)-1-(4'-benzole acid)-benzoatoproPionate by reacting (S)-2-chloro-3-(4-benzamidoacetophcnyl)-l-(l-chlorotaenzoic acid) propionate with 4-hydroxyben7oic acid in presence of a catalyst and dry organic solvent under inert atmosphere;
viii) a eighth step of preparation of (S)-2-chloro-3-(4-
benzamido-actophenyl)-1-(4'-l-chlorobenzoic acid)-
benzoatopropinnate by reacting (S) -2-chloro-3-(4-
benzamidoacetopheny1)-l-(4'-benzoic acid)-benzoatapropionate with thionyl chloride);
ix) a nineth step of preparation of (S)—2-chlaro-3-(4-
benz ami do—acei opheny 1 ) -1 -- ( 4 ' -dodecy1 ax ybenzoy 1 ) -benz oatapr opi onat e by reacting (S)-2-chloro—3—(4—benzamidoacetophenyl)—1—(4'— l-chlorobenzoic acid)-benzoatopropionate with 1-dodecanol in presence of a catalyst and dry organic solvent under inert atmosphere.
According to the present invention, preparation o-f this material comprises a total of nine steps followed by various compositions under different conditions.
Thp first step comprises the process of nucleophilic
substitution of -NH2 group from (S)-2-amino-3-
(4-hydroxyphenyi)-propionic acid by a chlorine atom via diazonium salt foroation, in the presence of freshly pulverized sor'; um nitrate, stirring the reaction mixture -for
6 hours at 0 -4°C, extracting with a suitable organic solvent, drying the organic layer with an appropriate drying agent for 12 hours, removing the excess solvent under reduced pressure, separating the compound by column chromatography using a silica gel column and appropriate eluwnt mixture, followed by recrystaliization to get crystals of (S)-2-chloro-3-(A- hydroxyphenyD-propionic acid.
Second step of the process illustrates the preparation of I-chloro-2-benzamidoacetic acid by refluxing 2-benzamidoacetic acid with thionyi chloride at 75° C for 8 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 10 hours, separating the compound by column chromatography using a sili' a tjel column and appropriate eluent mixture.
Third step of the process describes the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic arid which by reacting (S)-2-chloro—3-(4— hydroxyphenyl )--propionic acid with l-chloro-2— benzamidoacetic acid in presence of a catalyst and 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 chromatography using a silica gal column and appropriate eluent mixture, followed by recrystallizai ion to get crystals of (S)-2-chloro-S-(4-benzatrddoacet fiphenyl) -propionic acid.
Fourth step of the process describes the preparation of (S)-1,2-dichloro-3-(4-benzamidoacetopheny1)-propionic acid by refluxing (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic. acid with thionyl chloride with constant stirring, removing the excess organic solvent by vacuum distillation, washing the product with suitable cold solvent.
Fifth step of the process describes the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l— benzoic acid prapionate by reacting (S)-i,2—dichloro—3—(4— benzaroidoacetophenyl) -propionic acid with 4—hyclr oxybenzoic acid in preservence oi A catalyst and dry organic solvent und»r inert atmosphere,stirring the reaction mixture initially at room temperature for 4 hours, refluxing the reaction mixture for a periori upto 18 hours, removing the excess organic solvent by vacuum distillation, washing the product with suitable colri -olvent, 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 p1. uent mixture.
Sixih step of the process describes the preparation of (S)—2-chlnro—3-(4-benzamidoacetophenyI)-1—(1-
chlorobenzoic acid) propionate by reacting (S)-2-chl benzamidoacetaphenyl)-1-benzoic acid propionate with thionyl chloride with constant stirring, removing the excess organic solvent by vacuum distillation, washing th*? 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 and appropriate eluent mixture, followed by recrystalii ration to get crystals of (S)-2-chloro-3-(4-benzamidoacetophenyD-l-d-chlorobensoic acid) propionate.
Seventh step of the process describes the preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-benzoic acidl-benzoatopropianate by reacting (S)-2-chloro-3— (4-benzamidocetophenyl)-l-(1-chlorobenzoic acid) propionate with 4-hydrnxybenzoic acid in presence o-f a catalyst and dry organic -solvent under inert atmosphere, stirring the reaction mixture initially at room temperature for 4 hours,refluxing the reaction mixture for & period upto 22 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.
Eigtith step of the process describee the preparation of (S)-2-chlaro-3-(4-benzamidoacetophenyl)-l-(4'-l-
chlorobenzoi r acid) -benzctatopropionate by reacting (S)-2-
chloro-3-(4-bn7.amidoacetophenyl)-i-(4'-benzole *cid)-
henzoatoprap)onate with thionyl chloride 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 12 hours, separating the compound by column chromatography iming a si lira gel column and appropriate eluent mixture.
Ninpth step o-f the process describes the preparation of (S)-2-chloro-3-(4-benzamido-acetophenyl)-l-(4'-dodecyl oxybenroyl )-benzoatopropionate by reacting (S)-2-chloro-3— (4 t(r-r7 amidoacetophenyl ) -1- (4 '—1—chlorobnzoi c aci d)-benzoatopropionate with 1-dodecanol in prrence of a ratalyst anrl dry organic solvent under inert atmosphere, stirring the reaction mixture initially at room tpmperature for ft hours, refluxing the reaction mixture for a period upto 16 hoursT rr'mdving the excess organic solvent by vacuum distillationt washing the product with suitable cold solvent, separating HIP compound by column chromatography using silica gel col \(mn and appropriate eluent mixture.
Acrording to another feature of the present invention, the inert atmosphere may be maintained by using ni trogen.
Acrrjrding to yet another feature of the prevent. invention, thr- catalyst used is such as tr i ethyl ami ne.
According to yet another feature o-f the present invention, the dry organic solvent used is such as dichloromethanp, benzene, methanol, dimethylformamide, diethylether.
According to yet another feature of the present invention, organic solvent used far purification of compound by column chromatography is such as actone, actonitrilT petroleum ether, dichloromethane.
According to yet another feature of the present invention, crying agent used is such as Kodium eulphate, phosphorous pp'ntoxide, calcium chloride.
A stpp wise process for the preparation of a room temperature 4e)rroelectric liquid crystal cowpound, (8)-2-chloro-3-(4-bfenzanudoacetophenyI )-i-(4'-dodecyloxybenzoyl )-benzoatopropi ornate, is presented as follovi
(S)-2-amino-3-(4-hydroxyphenyl)-propionic acid (S)-2-
chloro-3-(4-hydroxyphenyl)-propionic acid
(S)-2-chloro-3-(4-hydroxyphenyl)-prop)onic acid was prepared by a known method and is described first 5.43 gram (30.0 mmol) of (S)-2-amino-3-(4-hydroxyphenyl)-propionic acid was dissolved in 20 ml of 6.0 N HCI and the solution was brought to 0°C. 2.72 gram (32.0 mmol) of freshly pulverised sodium nitrate was added to the solution in small portions with vigorous stirring while maintaining the reaction temperature between 0 and 5°C. The reaction mixture was stirred for 16 h. The solution was then extracted with 40 ml of diethylether and the etherial layer was dried over anhydrous sodium sulphate for 12 h. (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid obtained as an yellow product on removing the excess solvent by distillation under reduced pressure was washed repeatedly with cold benzene, seperated by chromatography through a silica gel column using a mixture of diethylether : acetone (5:1 v/v) as eluent. The product was recrystallized from hot dichlorornethane and dried over P2O5 for 12 h. to get an yield of 3.2 gram (53.2%).
Step 2
2-benzamidoacetic acid l-chloro-2-benzamidoacetic acid
l-chloro-2-benzamidoacetic acid was prepared by mixing together 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 benzene 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 of get an yellow solid product which was suction filtered, washed several times with cold methanol and dried over anhydrous calcium chloride for l0h. The product was purified by passing through a silica gel column using a mixture of petroleum ether: acetonitrile (5:1 v/v) as eluent to get 2.6 gram (52.6%) of l-chloro-2-benzamidoacetic acid.
l-chloro-2-benzamidoacetic acid + (S)-2-chloro-3-(4-hydroxyphenyl)-
propionic acid (S)-2-chloro-3-(4-benzamidoacetophenyl)-
propionic acid
3.95 (20.0 mmol) of l-chloro-2-benzamidoacetic acid prepared as illustrated in step 2 and 5.0 gram. (25.0 mmol) of (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid prepared as described in step 1 were magnetically stirred in 40 ml dry dichloromethane at ambient temperature for 2 h. 0.5 ml (3,6 mmol) of triethylamine was then added to the reaction mixture drop wise and the reaction mixture was refluxed at 60°C with constant stirring for 12 h. The yellow coloured (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid obtained on cooling the reaction mixture to room temperature was filtered off, washed repeatedly with cold methanol and recrystallised from hot acetone and dried over P2O5 for 12 h. The resultant product was further purified by chromatography through a silica gel column using a mixture of diethylether: acetone (5:1 v/v) as eluent to get an yield of 2.81 gram (69.82%).
Step 4
(S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid (S)-
1,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid
(S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid was prepared by dissolving 5.84 gram (16.2 mmol) of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid prepared as illustrated in step 3 in 40 ml of absolute dichloromethane and to it added 2.5 ml (21.2 mmol) of thionylchloride with constant stirring. The reaction mixture was then heated to 60°C and the stirring was continued till the evalution SO2 ceased. On cooling the reaction mixture to room temperature (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid was separated as a white solid which was filtered off and washed several times with cold chloroform and the final product was recrystallized from hot benzene solution. The product was further purified by column chromatography through a silica gel column using a mixture of petroleum ether and acetone in 5:1 v/v as eluent to get 4.22 gram (68-84%) of (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid.
: 12 :
StcpS
(S)-l,2-dichloro-3-(4-beny.amidoacetopheriyl)-propionic acid + 4-hydroxybenzoic acid
(S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acid-piopionale
(S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acidpropionate prepared by mixing together absolute dichloromethane .solutions of (S)-l(2-dichloro-3-(4-ben2amidoacetophenyl)-propionic acid (4.81 gram/12.7 mmol in 20 ml of dry dichloromelliane) prepared as described in step 4 and 4-hydroxybenzoic acid (1.8 gr am/13.0 nunol in 20 ml of dry dichlorometliane) in equimolar ratio and the reaction mixture was stirred for 4 h at room temperature. 0.4 ml (3.1 mmol) of trielhylamine was then added to the reaction mixtuie drop wise with constant sliming. 'the reaction mixture was then relluxed
t
at 75 °C for 18 h. The yellow coloured solution containing (S)-2-chloro-3-(4-benzamidoacetophenyl)-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 chromatoghaphy through a silica gel column using a mixture of petroleum ether and acetonitrile in 5 : 1 v/v as eluent. The yield obtained was 3.74 gram (63.17 %).
Step 6
(S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acidpropionate (S)-2-chloro-
3-(4-benzamidoacetophenyl)-l-(l-chloro-benzoic acid)-propionate
(S)-2-chloro-3-(4-beiizamidoacetophenyl)-l-(l-chloro-bc.nzoic acid)-propionate was prepared by disolving 3.32 g (7.11 mrnol) of (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-benzoic acid-propionate prepared as descibed in slop 5 in 40 ml of absolute dichloromethane and to it added 0.76 ml (10.4 mmol) of thionylchloride with constant stirring under nitrogen atmosphere. The reaction mixture was then heated to 60 °C and the stirring was continued till the evalution of SO2 ceased. On cooling the reaction mixture to room temperature (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(l-chloro-beii7.oic 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 reciyslallized from hot benzene solution to get 1.86 gram (52.32 %) of (S)-2-chloro-3-(4-ben/amidoacelophenyl)-l-(l-chlorobenzoic acid)-propionale.
Step 7
(S)-2-cliloro-3-(4-benzaloncetoplieiiyl)-l-(l-clilorol)ei-'.oic acid)-propioiinll-hydioxybeii/oic
acid (S)-2-chlon)-.)-('1-|)eii7,aitiidoaceloplienyl)-]-(4'-beii7oii- and)-
benzoatopropioiiate
(S)-2-chloro-3-(44)en/amidoacetop- add)-ben7,O}ifopropiouale was- prepared by mixing together absolute didiloromelhane solutions of (S)-2-chloro-3-(4-ben7.ainidoacelophenyl)-l-
(l-dilorobcnzoic acid)-pioj)ioiiatc (2.65 gram/5.3 mmol in 2.0 nil dry dichloromelhaue) prepared as illustrated in slep 6 and -1 hydroxybcnzoic acid (0.95 gram/68 rnrnol in 15 nil oi'diy didilotoinelhane) and the reaction mixture was stirred at ambient temperature for 4 h under nitrogen almnsphei e. 0.45 nil (3.2 miuol) of'trieliiylaniine was then added lo the reaction mixture drop wise and i ellnxed (he reaction mixture at 75 °C with constant stirring for 22 h. The yellow coloured solid of (S) •?. diloro-.?-(4-l)en:r.!iHiidoacetophcnyl)-l-(4"-benzoic% acid)-benzoatopropionate was separated by removing (lie excess solvent by vacuum distillation, washed twice with cold elhanol and chronialoRiiiphed through a silica gel column using a mixture ol'pelioleum elher : acetone (5 : 1 v/v) as eluent. The product was reciystalli/.ed fi'om hot luMi::eiu) solution. The yield obhnned was 1.64 gram (51.48 "i.).
Step 8
(S)-2-cli!(M'o-3-(4-benzamidoacetoplienyI)-l-(4'-beii7,oic acid)-ben/oatopropionate
(S)-2-chloro-3-(4-bc(nzainidoacetoplienyl)-l-(4'-l-dilorobcnzoic acid)-l)eii;i.oalopio[)ionate
(S)-2-chloro-3-(4-ben)',amidoacetophenyl)-l-(4M-chlorobenzoic acid)-ben/.oalopi()|'ionate was pre})ared by disolving 2.08 grain (3.3 mmol) of (S)-2-diloro-3-(4-benzmnidoacetop!uMiyl)-1-(4'-benzoic ac%id)-benzoatopiopionate prepared as described in step 7 in 40 ml ol' absolute dichloiomethajie and to if added 0.65 ml (4.7 nimol) of thionylchloride with constant sliiring undei uilrogeu atmosphere. 'J'he reaction niiture wa^ then heated to 60 °C (uid the stirring was continued till the evalution of SO? ceased. On cooling the reaction mixture to room temperature (S)-.?-chloro-3-(4-beu/.amidoacetophenyl)-! (I'-l-chlorobeu/.oic acid)-ben/.oatoj)i opionate was sepaialod as a while colour product which was lilleivd oif, washed repeatedly with cold chloroform and di iod over vacuuq for 12 h. (S)-2-cliloi() 3-(4-ben)'.ajui(loacetophenyl)-l-(4'-l-chlorobenzoic arid)-ben:-,oatopro-pionate was purified by column cinematography through a silica gel column iisma a mixture of petroleum ether : acelonr (5 : 1 v/v) a,s elueut. The product was reoy.';l:tlli:vd from hot dichloromelhane solution to get an yield of 1.13 gram (52.64 %).
Step 9 (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-(4'-1-chiorobenzoic
acid)-benzoatopropionate -» i-dodecanol (S)-
2-chl or 0-3-( 4-benz ami doacirtDphenyl ) -1- (4 '-dodecyloxybenzoyl )-
benzoatopropionate
(S)-2-chloro-3-(4-benz ami doacetophenyl)-1-(4'-
dodecyloxybenzoyl)-benzoatopropionate Mae prepared by
stirring together absolute dichloromethane solutions of tS)-
2-chioro-3-(4-benzamidaacetophenyl)-1-(4'—l-chlorobenzoic
acid)-benzoatoprapionate (2.1 gran/3.4 mmol in 15 ml of dry
dichioromethane) prepared a* illustrated in step 8 and 1—
dadecanol ((Z.3 gram/4.3 mmol in 15 ml of dry dichloromethane)
under nitrogen atmosphere at room temperature nd the
reaction mixture Mas stirred for 5 h. 0.5 ml (3.6 mmol) o-f
triethyl amine was added to the reaction mixture drop wise and
the reaction mixture refluxed at 75°C for 16 h. The yellow
coloured solution containing (S)-2-chloro-3-(4-
benzamidaacetoph»nyl)-i-(4'-octyloxybenzoyl)-
benzoatopropionate was isolated as an yellow golly product after removing the excess solvent by vacuum distillation and the product was; further purified by column chrotwutography through a silica gel column using a mixture Of petroleum etheri acetonitrile (5s 1 v/v) as eluervt to get n yield of 1.33 gram (51-(3".(-
ADVANTAGES
The room temperature ferroelectric liquid crystal compound .prepared by the process of this -invention )thich 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 applirational purposes are the mixtures of more than one component.
The room temperature ferroelectric liquid crystal compound prepared by the process of this invention i» therefore useful for both fundamental as well applied research aspects including for the non-linear optical applications. The room temperature ferroelectric liquid crystal compound can further be used as hat materials for the preparation of other FLC mixtures.
The need for this type of room temperature ferroelectric materials aw strongly felt because the preparation and characterization of FLC mixtures is time consuming as well as expensive. These compound* prepared as .per the process of this invention can be 'directly used in the
-i
applinational aspects such as polarization controller
switching attenuators, vdisplay 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 magnitude of these parameters are found to be of in good agreement with those of commercially available compounds. In fact some of the above properties envisage that this compound showed better physical characteristic than the commercially available compound.

WE CLAIM:
1. A process for the preparation of a novel room temperature ferroelectric liquid crystal compound (S)-2-chloro-3-(4-benzamidoacetophenyl)-l-
(4'-dodecyloxybenzoyl)-benzoatopropionate which comprises in the step of:
i) a first step of 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 freshly pulverized sodium nitrate to obtain crystals of (S)-2-chloro-3-(4~ hydroxyphenyl)-propionic acid;
ii) a second step of preparation of l-chloro-2-benzamidoacetic acid by refluxing 2-benzamidoacetic acid with thionyl chloride;
iii) a third step of preparation of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid which by reacting (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid with l-chloro-2-benzamidoacetic acid in presence of a catalyst and in dry organic solvent under inert atmosphere;
iv) a fourth step of preparation of (S)-l, 2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid by 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 a catalyst and dry organic solvent under inert atmosphere;
Step 1
(S)-2-amino-3-(4-hydroxyphenyl)-propionic acid (S)-2-
chloro-3-(4-hydroxyphenyl)-propionic acid
(S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid was prepared by a known method and is described first 5.43 gram (30.0 mmol) of (S)-2-amino-3-(4-hydroxyphenyl)-propionic acid was dissolved in 20 ml of 6.0 N HCI and the solution was brought to 0°C. 2.72 gram (32.0 mmol) of freshly pulverised sodium nitrate was added to the solution in small portions with vigorous stirring while maintaining the reaction temperature between 0 and 5°C. The reaction mixture was stirred for 16 h. The solution was then extracted with 40 ml of diethylether and the etherial layer was dried over anhydrous sodium sulphate for 12 h. (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid obtained as an yellow product on removing the excess solvent by distillation under reduced pressure was washed repeatedly with cold benzene, seperated by chromatography through a silica gel column using a mixture of diethylether : acetone (5:1 v/v) as eluent. The product was recrystallized from hot dichloromethane and dried over P2O5 for 12 h. to get an yield of 3.2 gram (53.2%).
Step 2
2-benzamidoacetic acid l-chloro-2-benzamidoacetic acid
l-chloro-2-benzamidoacetic acid was prepared by mixing together 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 benzene 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 of get an yellow solid product which was suction filtered, washed several times with cold methanol and dried over anhydrous calcium chloride for l0h. The product was purified by passing through a silica gel column using a mixture of petroleum ether: acetonitrile (5:1 v/v) as eluent to get 2.6 gram (52.6%) of l-chloro-2-benzamidoacetic acid.
Step3
l-chloro-2-benzamidoacetic acid + (S)-2-chloro-3-(4-hydroxyphenyl)-
propionic acid (S)-2-chloro-3-(4-benzamidoacetophenyl)-
propionic acid
3.95 (20.0 mmol) of l-chloro-2-benzamidoacetic acid prepared as illustrated in step 2 and 5.0 gram. (25.0 mmol) of (S)-2-chloro-3-(4-hydroxyphenyl)-propionic acid prepared as described in step 1 were magnetically stirred in 40 ml dry dichloromethane at ambient temperature for 2 h. 0.5 ml (3,6 mmol) of triethylamine was then added to the reaction mixture drop wise arid the reaction mixture was refluxed at 60°C with constant stirring for 12 h. The yellow coloured (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid obtained on cooling the reaction mixture to room temperature was filtered off, washed repeatedly with cold methanol and recrystallised from hot acetone and dried over P2O5 for 12 h. The resultant product was further purified by chromatography through a silica gel column using a mixture of diethylether: acetone (5:1 v/v) as eluent to get an yield of 2.81 gram (69.82%).
Step 4
(S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid (S)-
1,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid
(S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid was prepared by dissolving 5.84 gram (16.2 mmol) of (S)-2-chloro-3-(4-benzamidoacetophenyl)-propionic acid prepared as illustrated in step 3 in 40 ml of absolute dichloromethane and to it added 2.5 ml (21.2 mmol) of thionylchloride with constant stirring. The reaction mixture was then heated to 60°C and the stirring was continued till the evalution SO2 ceased. On cooling the reaction mixture to room temperature (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid was separated as a white solid which was filtered off and washed several times with cold chloroform and the final product was recrystallized from hot benzene solution. The product was further purified by column chromatography through a silica gel column using a mixture of petroleum ether and acetone in 5:1 v/v as eluent to get 4.22 gram (68-84%) of (S)-l,2-dichloro-3-(4-benzamidoacetophenyl)-propionic acid.
catalyst and dry organic solvent as herein described 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 a cold solvent, separating the compound by column chromatography using a silica gel column and eluent mixture comprising petroleum ether and acetonitrile.
11. A process for the preparation of a novel room temperature
ferroelectric liquid crystal compound, (S)-2-chloro-3-(4-
benzamidoacetophenyl)— 1 - (4 '-dodecyloxybenzoyl) -benzoatopropionate, substantially as herein described and exemplified in the examples.

Documents:

942-del-1998-abstract.pdf

942-DEL-1998-Claims.pdf

942-del-1998-correspondence-others.pdf

942-del-1998-correspondence-po.pdf

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

942-del-1998-drawings.pdf

942-del-1998-form-1.pdf

942-del-1998-form-19.pdf

942-del-1998-form-2.pdf

942-del-1998-form-3.pdf

942-del-1998-gpa.pdf

942-del-1998-petition-others.pdf

« Previous Patent

Next Patent »

Patent Number

215238

Indian Patent Application Number

942/DEL/1998

PG Journal Number

10/2008

Publication Date

07-Mar-2008

Grant Date

22-Feb-2008

Date of Filing

15-Apr-1998

Name of Patentee

THE SECRETARY DEPARTMENT OF ELECTRONICS., GOVT. OF INDIA

Applicant Address

ELECTRONICS NIKETAN, 6 CGO COMPLEX, NEW DELHI - 110 003, INDIA

Inventors:

#	Inventor's Name	Inventor's Address
1	DR. VENKATA GOPALAKRISHNA MURTHY PISIPATI	LIQUID RESEARCH AND EDUCATION FACULTY OF PHYSICAL SCIENCES, NAGARJUNA UNIVERSITY, NAGARJUNA NAGAR, 522510, A.P.
2	ANJANA KUMAR, POLURI	LIQUID RESEARCH AND EDUCATION FACULTY OF PHYSICAL SCIENCES, NAGARJUNA UNIVERSITY, NAGARJUNA NAGAR, 522510, A.P.

PCT International Classification Number

G06F 1/33

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA