Title of Invention

'A PROCESS FOR THE PREPARATION OF NOVEL MONOMERS BASED ON DISUBSTITUTED CYCLOAKANONES'

Abstract

The present invention reports a process for the preparation of novel monomers based on disubstituted cycloalkanones, which comprises reacting in an inert atmosphere methacryloyl chloride with 2 - (4-nitro benzylidene) -6-4-[(2-hydroxy ethyloxy) benzylidene] cyclo - alkanones, in a dry polar aprotic solvent, in the presence of a catalyst, stirring the reaction mixture at a temperature in the range of 25 to 35°C, for a period ranging from 10 to 14 hours, separating the solids, washing the filtrate with cold hydrochloric acid and water, drying the organic phase over a drying agent , removing the aprotic solvent under reduced pressure, purifying by conventional methods to obtain the pure product. The monomers prepared by this process is useful for the synthesis of new side chain liquid crystalline polymers which can be used for non linear optical applications.

Full Text

This invention relates to a process for the preparation of novel monomers based on disubstituted cycloalkanones. Particularly this invention relates to a process for the preparation of novel monomers based on 2,6-disubstituted cyclohexanones/ 2,5-disubstituted cyclo-pentanones, useful for the preparation of new side chain liquid crystalline polymers. More particularly it relates to a process for the preparation of 2-(4-nitro benzylidene)- 6 -[4-(2-methacryloyl ethyloxy) benzylidene] cycloalkanones having general formula 1 given in the drawing accompanying this specification, wherein R = nil or -CH2 or -CH(CH3) and n - 2 to 6. The monomers prepared as per the process of this invention are compounds which form part of the polymeric structure in liquid crystalline polymers. If the monomer has mesogen that forms part of the backbone of the polymers, then the polymers are known as main chain liquid crystalline polymers and if it is in the form of pendant groups along the backbone of the polymers, then the polymers are referred to as side chain liquid crystalline polymers. The monomer prepared as per the process of this invention are therefore useful for the synthesis of new side chain liquid crystalline polymers that could be used for non-linear optical applications. The monomers prepared by the process of this invention are prepared from 2-(4-nitro benzylidene)-6-4-[(2-hydroxy alkoxy) benzylidene] cycloalkanones, having a general formula as shown in figure 2 of the drawing accompanying this specification. In our copencling application number 424/DEL/97, we have described and claimed our process for the preparation of 2-(4-nitro benzylidene)-6-4-[(2-hydroxy ethyloxy) benzylidene] cyclo-alkanones, structurally represented in figure 2 of the drawing accompanying this specification. Polymers with non-linear properties are potential candidates in applications such as waveguide electro-optic modulators, switches and optical frequency doubling devices, fast response optical communication and computing systems. The interest in developing newer materials in the area of polymeric materials for non-linear applications is growing at a tremendrous pace. The need for newer materials for use in non-linear optical application is strongly felt by researchers. The need is desired by those involved in the developmental efforts for optical signaling manipulation, parallel optical image processing systems in the wake of developments in the area of fibre optics. The material development is directed towards materials with non-linear properties. It is known that response factor to radiation is linear so long as intensity of radiation is weak. However, in the presence of intense source such as the laser, non-linear effects are detectable. Materials with large non-linear optical coefficients are desired for applications in the areas of electro-optical switching, higher data storage devices and the like. The other characteristic feature of these materials is fast response times required for processing desired device structures. Properties that are critical for materials to qualify for non-linear optical applications include transparency, thermal, photochemical and chemical stability, dielectric constant etc. Both inorganic and organic salts exhibit non-linear optical properties. Materials that have been extensively used in the area of non-linear optical applications are inorganic salts such as potassium dideuterium phosphate, lithium niobate, potassium titanyl phosphate etc. Organic materials offer the advantage of high density packing and specific arrangement of molecules in the crystalline state. While the organic materials offer superior properties in comparison with inorganic materials, practical utilization poses several problems. In addition, the development of organic materials which offer superior non-linear optical properties have been hindered because of the low threshold limits of these materials on exposure to strong radiations such as laser beam. Amongst the various approaches towards development of materials for non-linear optical applications such as crystal growth, growth in confined structures, monolayer assemblies such as the Langmuir-Bludget films, poled polymer systems has been found to be a fruitful approach. The advantages offered by the poled polymer systems are greater flexibility in the selection of mesogenic and polymeric structures and ease of fabrication of devices. The side chain liquid crystalline polymer synthesized using the mesogens as per the process of this invention could be used in poled polymer systems. Poling of polymers is done by subjecting the polymer usually in the form of a film to an external electric field at an elevated temperature followed by cooling to ambient temperature before the applied external field is removed. During this process the dipolar species in the polymer film would reorient and a net alignment is retained in the film. For a polymer to be useful for non-linear optical applications, it must satisfy primary optical property requirements. The primary optical property is characterized by the material having substantial transparency to light of desired frequency. The other criteria is that the poled polymer does not lose its order effected by the poling technique over the operating temperatures. The main object of the present invention is therefore to provide a process for the preparation of novel monomer based on disubstituted cycloalk-anone useful for the preparation new side P chain liquid crystalline polymers that are useful in non-linear optical applications. Accordingly, the present invention provides a process for the preparation of novel monomers based on disubstitued cycloalkanones, having a general formula 1 given in the drawing accompanying this specification, where R = nil or - CH2 or CH-CH3, n = 2 to 6, which comprises reacting in an inert atmosphere methacryloyl chloride with 2 - (4-nitro benzylidene) -6-4-[(2-hydroxy ethyloxy) benzylidene] cyclo - alkanones, having a general formula 2 wherein R= nil or -CH2 or CH-CH3, n = 2 to 6, as specified in the drawing accompanying this specification, in a dry polar aprotic solvent, in the presence of a catalyst in the form of trialkylamine, stirring the reaction mixture at a temperature in the range of 25 to 35°C, for a period ranging from 10 to 14 hours, separating the solids by conventional methods such as filtration, washing the filtrate with about 5% v/v aqueous alkali metal hydroxide solution, then with about 2N cold hydrochloric acid and water, drying the organic phase over a drying agent selected from anhydrous sodium sulphate , removing the aprotic solvent under reduced pressure, purifying by conventional methods to obtain the pure product. According to an embodiment of the invention, the inert atmosphere may be maintained by using nitrogen or argon. According to another embodiment of the invention, the 2-(4-nitro benzylidene)-6-4-[(2-hydroxy alkoxy) benzylidene] cycloalkanone used is prepared as per the process described and claimed in our copending application number 424/DEL/97. According to yet embodiment feature of the invention, the dry polar aprotic solvent used be such as dichloromethane,' chloroform, dichlorouthano. According to yet embodiment feature of the invention, the catalyst used may be such as trialkyamine, preferably triethylamine. According to still another embodiment of the invention, the drying agent used may be chosen from sodium sulphate, magnesium sulphate, calcium chloride. The invention is described with reference to the examples given below which are illustrative in nature and should not be construed to limit the scope of this invention. Example 1 : In an inert atmosphere of nitrogen, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 760 mg 2-(4-nitro benzylidene)-6 - [4 -(2-hydroxy ethyloxy) benzylidene] cyclohexanone and 140 mg of triethylamine in 20 ml of dichloromethane. The resulting mixture was stirred at temperature of 25°C for period of 12 hours. The reaction mixture was then filtered through glass wool. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous sodium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4 % acetone in petroleum ether (V/V) mixture as eluent to get pure 2-(4-nitro benzylidene)-6-[4-(2-methacryloyl ethyloxy) benzylidene] cyclohexanone. The yield obtained was 820 mg. The product obtained as per the process of invention will have the following characteristics : IR absorption (using KBr pellet) 2930, 1706, 1662, 1628, 1589, 1554, 1506, 1469, 1416, 1337, 1251, 1165, 1010, 930, 853 cm-1. 1H NMR in CDC13 8.25 (d,2H), 7.80 (d,2H), 7.55 (d, 2H) , 7.45 (d,2H), 7.00 (d,2H), 6.18 and 5.56 (d and d, 2H) , 4.30 (t,2H), 4.13 (t,2H), 3.00 (t,4H), 1.98 (s,3H), 1.80 (m,2H). Example 2 : In an inert atmosphere of argon, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 786 mg 2-(4-nitro benzylidene)-6-[4-(3-hydroxy propyloxy) benzylidene] cyclohexanone and 140 mg of triethylamine in 20 ml of chloroform as aprotic organic solvent. The resulting mixture was stirred at a temperature of 30°C for a period upto 14 hours. The reaction mixture was filtered through glass wool after cooling to ambient temperature. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous sodium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4 % acetone in petroleum ether (V/V) mixture to get pure 2-(4-nitro benzylidene)-6 - [4 - (3-methacryloyl propyloxy) benzylidene] cyclohexanone. The yield obtained was 830 mg. The product obtained as per the process of the invention will have the following characteristics : IR absorptions (using KBr pellet) : 2930, 1706, 1662, 1628, 1589, 1554, 1506, 1469, 1416, 1337, 1251, 1165, 1010, 930, 853 cm-1. 1H NMR in CDC13 : 8.25 (d,2H), 7.80 (d,2H), 7.55 (d, 2H) , 7.45 (d,2H), 7.00 (d,2H), 6.18 and 5.56 (d and d,2H), 4.25 (t,2H), 4.05 (t,2H), 3.00 (t,4H), 1.98 (s,3H), 1.80 to 1.50 (m,4H). Example 3 : In an inert atmosphere of nitrogen, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 826 mg 2-(4-nitro benzylidene)-6 - [4-(4-hydroxy butyloxy) benzylidene] cyclohexanone and 140 mg of triethylamine in 20 ml of dichloroethane as aprotic organic solvent. The resulting mixture was stirred at temperature of 35° for period upto 10 hours. The reaction mixture was cooled to ambient temperature and filtered through glass wool. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous potassium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous magnesium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4% V/V acetone in petroleum ether (V/V) mixture as eluent to get pure 2-(4-nitro benzylidene)-6-[4-(4-methacryloyl butyloxy) benzylidene] cyclohexanone. The yield obtained was 882 mg. The product obtained as per the process of the invention will have the following characteristics : IR absorptions (using KBr pellet) : 2930, 1706, 1662, 1628, 1589, 1554, 1506, 1469, 1416, 1337, 1251, 1165, 1010, 930, 853 cm-1. 1H NMR in CDC13 : 8.25 (d,2H), 7.80 (d, 2H) , 7.55 (d,2H), 7.45 (d,2H), 7.00 (d,2H), 6.18 and 5.56 (d and d, 2H) , 4.25 (t,2H), 4.05 (t,2H), 3.00 (t,4H), 1.98 (s,3H), 1.80 to 1.50 (m,6H). Example 4 : In inert atmosphere of argon, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 870 mg 2- (4-nitro benzylidene) -6- [4 - (6-hydroxy hexyloxy) benzylidene] cyclohexanone and 140 mg of triethylamine in 20 ml of dichloromethane as aprotic organic solvent. The resulting mixture was stirred at a temperature of 30° for 12 hours. After 12 hours, the reaction reaction mixture was filtered through glass wool. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous sodium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4% acetone in petroleum ether (V/V) mixture as eluent to get pure 2-(4-nitro benzylidene)-6 - [4-(6-methacryloyl hexyloxy) benzylidene] cyclohexanone. The yield obtained was 880 mg. The product obtained as per the process of the invention will have the following characteristics : IR absorptions (using KBr pellet) 2930, 1706, 1662, 1628, 1589, 1554, 1506, 1469, 1416, 1337, 1251, 1165, 1010, 930, 853 cm-1. 1H NMR in CDC13 : 8.25 (d,2H), 7.80 (d,2H), 7.55 (d,2H), 7.45 (d,2H), 7.00 (d,2H), 6.18 and 5.56 (d and d,2H), 4.25 (t,2H), 4.05 (t,2H), 3.00 (t,4H), 1.98 (s,3H), 1.80 to 1.45 (m,10H). Example 5 : In an inert atmosphere of nitrogen, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 730 mg 2-(4-nitro benzylidene)-5-[4-(2-hydroxy ethyloxy) benzylidene] cyclopentanone and 140 mg of triethylamine in 20 ml of chloroform as aprotic organic solvent. The resulting mixture was stirred at a temperature of 35°C for 11 hours. After 11 hours the reaction mixture was cooled to ambient temperature and the reaction mixture was filtered through glass wool. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous sodium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous magnesium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4% acetone in petroleum ether (V/V) mixture as the eluent to get pure 2-(4-nitro benzylidene)-5- [4-(2-methacryloyl ethyloxy) benzylidene] cyclopentanone. The yield obtained was 800 mg. The product obtained as per the process of the invention will have the following characteristics : IR absorptions (using KBr pellet) : 2940, 1701, 1652, 1621, 1592, 1565, 1508, 1478, 1422, 1340, 1316, 1251, 1173, 1121, 1002, 930, 851 cm-1. 1H NMR in CDC13 : 8.30 (d,2H), 7.75 (d,2H), 7.60 (d,2H), 7.5 (d,2H), 6.95 (d,2H), 6.10 and 5.52 (d and d,2H), 4.22 (t,2H), 4.00 (t,2H), 3.14 (s,4H), 1.98 (s,3H). Example 6 : In an inert atmosphere of nitrogen, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 760 mg 2-(4-nitro benzylidene)-5-[4 -(3-hydroxy propyloxy) benzylidene] cyclopentanone and 140 mg of triethylamine in 20 ml of dichloroethane as aprotic organic solvent. The resulting mixture was stirred at a temperature of 25°C for 14 hours. After 14 hours the reaction mixture was filtered through glass wool. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous potassium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4% acetone in petroleum ether (V/V) mixture as eluent to get pure 2-(4-nitro benzylidene)-5- [4-(3-methacryloyl propyloxy) benzylidene] cyclopentanone. The yield obtained was 828 mg. The product obtained as per the process of the invention will have the following characteristics : IR absorptions (using KBr pellet) : 2940, 1701, 1652, 1621, 1592, 1565, 1508, 1478, 1422, 1340, 1316, 1251, 1173, 1121, 1002, 930, 851 cm-1. 1H NMR in CDC13 : 8.30 (d,2H), 7.75 (d,2H), 7.60 (d,2H), 7.50 (d, 2H) , 6.95 (d,2H), 6.10 and 5.52 (d and d,2H), 4.20 (t,2H), 3.95 (t,2H), 3.14 (s,4H), 1.98 (s,3H), 1.80 (m,2H). Example 7 : In inert atmosphere of argon, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 786 mg 2-(4-nitro benzylidene)-5 -[4 -(4-hydroxy butyloxy) benzylidene] cyclopentanone and 140 mg of triethylamine in 20 ml of chloroform as aprotic organic solvent. The resulting mixture was stirred at a temperature of 30°C for 12 hours. After 12 hours, the reaction mixture Was fiboded throught glass wool. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous sodium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4% acetone in petroleum ether (V/V) mixture as eluent to get pure 2-(4-nitro benzylidene)-5-[4-(4-methacryloyl butyloxy) benzylidene] cyclopentanone. The yield obtained was 838 mg. The product obtained as per the process of the invention will have the following characteristics : IR absorptions (using KBr pellet) : 2940, 1701, 1652, 1621, 1592, 1565, 1508, 1478, 1422, 1340, 1316, 1251, 1173, 1121, 1002, 930, 851 cm-1. 1H NMR in CDC13 : 8.30 (d,2H), 7.75 (d,2H), 7.60 (d,2H), 7.50 (d,2H), 6.95 (d,2H), 6.10 and 5.52 (d and d,2H), 4.20 (t,2H), 3.95 (t,2H), 3.14 (s,4H), 1.98 (s,3H), 1.80 to 1.45 (m,4H). Example 8 : In inert atmosphere of nitrogen, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 842 mg 2-(4-nitro benzylidene)-5-[4-(6-hydroxy butyloxy) benzylidene] cyclopentanone and 140 mg of triethylamine in 20 ml of dichloromethane as aprotic organic solvent. The resulting mixture was stirred at a temperature of 25°C for 14 hours. After 14 hours, the reaction mixture was filtered through glass wool. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous sodium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous magnesium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4% acetone in petroleum ether (V/V) mixture as eluent to get pure 2-(4-nitro benzylidene)-5-[4-(6-methacryloyl hexyloxy) benzylidene] cyclo-pentanone. The yield obtained was 900 mg. The product obtained as per the process of the invention will have the following characteristics : IR absorptions (using KBr pellet) : 2940, 1701, 1652, 1621, 1592, 1565, 1508, 1478, 1422, 1340, 1316, 1251, 1173, 1121, 1002, 930, 851 cm-1. 1H NMR in CDC13 : 8.30 (d,2H), 7.75 (d, 2H) , 7.60 (d,2H), 7.50 (d,2H), 6.95 (d,2H), 6.10 and 5.52 (d and d,2H), 4.20 (t,2H), 4.00 (t,2H), 3.14(s,4H), 1.98 (s,3H), 1.80 to 1.45 ( (m,8H). Example 9 : In an inert atmosphere of nitrogen, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 786 mg 2-(4-nitro benzylidene)-6 - [4-(2-hydroxy ethyloxy) benzylidene]-4-methyl cyclohexanone and 140 mg of triethylamine in 20 ml of dichloromethane aprotic organic solvent. The resulting mixture was stirred at a temperature of 30°C for 12 hours. After 12 hours the reaction mixture was cooled to ambient temperature and the reaction mixture was filtered through glass wool. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous potassium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4% acetone in petroleum ether (V/V) mixture as eluent to get pure 2-(4-nitro benzylidene)-6-[4-(2-methacryloyl ethyloxy) benzylidene]-4-methyl cyclohexanone. The yield obtained was 850 mg. The product obtained as per the process of the invention will have the following characteristics : IR absorptions (using KBr pellet) : 2936, 1708, 1668, 1630, 1589, 1560, 1504, 1464, 1414, 1340, 1316, 1254, 1165, 1110, 1002, 934, 851 cm-1. 1H NMR in CDC13 : 8.30 (d,2H), 7.80 (d,2H), 7.60 (d,2H), 7.50 (d,2H), 7.00 (d,2H), 6.16 and 5.52 (d and d,2H), 4.52 (t,2H), 4.30 (t,2H), 3.14 to 2.90 (t,t 2H) , 2.65 to 2.45 (t,t,2H) 2.00 (s,3H), 1.80 (m,lH), 1.10 (d,3H). Example 10 : In an inert atmosphere of argon, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 815 mg 2-(4-nitro benzylidene)-6-[4-(3-hydroxy propyloxy) benzylidene]-4-methyl cyclohexanone and 140 mg of triethylamine in 20 ml of dichloroethane as aprotic organic solvent. The resulting mixture was stirred at a temperature of 35°C for 14 hours. After 14 hours, the reaction mixture was cooled to ambient temperature and the reaction mixture was filtered through glass wool. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous sodium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4% acetone in petroleum ether (V/V) mixture as eluent to get pure of 2-(4-nitro benzylidene) - 6 - [4-( 3 - methacryloyl propyloxy) benzylidene]-4-methyl cyciohexauone. The yield obtained was 875 mg. The product obtained as per the process of the invention will have the following characteristics : IR absorptions (using KBr pellet) : 2936, 1708, 1668, 1630, 1589, 1560, 1504, 1464, 1414, 1340, 1316, 1254, 1165, 1110, 1002, 934, 851 cm-1. Example 11 : In an inert atmosphere of nitrogen, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 842 mg 2-(4-nitro benzylidene)- 6 -[4-(4-hydroxy butyloxy) benzylidene]-4-methyl cyclohexanone and 140 mg of triethylamine in 20 ml of dichloromethane as aprotic organic solvent. The resulting mixture was stirred at a temperature of 25°C for 12 hours. After 12 hours the reaction mixture was filtered through glass wool. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous sodium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4% acetone in petroleum ether mixture as eluent to get pure of 2-(4-nitro benzylidene)-6- [4-(4-methacryloyl butyloxy) benzylidene]-4-methylcyclohexanone. The yield obtained was 890 mg. The product obtained as per the process of the invention will have the following characteristics IR absorptions (using KBr pellet) : 2936, 1708, 1668, 1630, 1589, 1560, 1504, 1464, 1414, 1340, 1316, 1254, 1165, 1110, 1002, 934, 851 cm-1. 1H NMR in CDC13 : 8.30 (d,2H), 7.80 (d,2H), 7.60 (d,2H), 7.50 (d, 2H) , 7.00 (d,2H), 6.16 and 5.52 (d and d,2H), 4.32 (t,2H), 4.22 (t,2H), 3.14 to 2.90 (t,t, 2H), 2.65 to 2.45 (t,t,2H) 2.00 (s,3H), 1.80 to 1.50 (m,5H), 1.10 (d,3H). Example 12 : In an inert atmosphere of nitrogen, 230 mg of methacryloyl chloride was slowly added to the ice cold solution consisting of 900 mg 2-(4-nitro benzylidene) - 6 - [4 - (6 -hydroxy hexyloxy) benzylidene]-4-methyl cyclohexanone and 140 mg of triethylamine in 20 ml of chloroform as aprotic organic solvent. The resulting mixture was stirred at a temperature of 30°C for 14 hours. After 14 hours the reaction mixture was cooled to ambient temperature and the reaction mixture was filtered through glass wool. The filtrate was washed sequentially with 25 ml of 5% (W/V) aqueous sodium hydroxide solution, 20 ml of cold 2N hydrochloric acid and finally with water. The organic extract was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The resulting crude product was purified by chromatography on silica-gel column using 4% acetone in petroleum ether (V/V) mixture as eluent to get pure of 2-(4-nitro benzylidene)-6-[4-(6-methacryloyl hexyloxy) benzylidene]-4-methyl cyclohexanone. The yield obtained was 940 mg. The product obtained as per the process of the invention will have the following characteristics : IR absorptions (using KBr pellet) : 2936, 1708, 1668, 1630, 1589, 1560, 1504, 1464, 1414, 1340, 1316, 1254, 1165, 1110, 1002, 934, 851 cm-1. 1H NMR in CDC13 : 8.30 (d,2H), 7.80 (d,2H), 7.60 (d,2H), 7.50 (d,2H), 7.00 (d,2H), 6.16 and 5.52 (d and d,2H), 4.32 (t,2H), 4.22 (t,2H), 3.14 to 2.90 (t,t, 2H) , 2.65 to 2.45 (t,t 2H) 2.00 (s, 3H) , 1.80 to 1.50 (m,9H), 1.10 (d,3H). The advantages of the process of invention are : 1. The product obtained as per the process of this invention, meets the stringent purity requirements as a monomer that could be used in the synthesis of new side chain liquid crystalline polymer for non linear optical applications. 2. The process is amenable for scale up to meet the requirements in this area of research. 3. The monomer can then be subsequently polymerised to prepare new side chain liquid crystalline polymer useful for non- linear optical applications. The new side chain liquid crystalline polymer prepared is useful for non-linear optical applications. Claim: 1. A process for the preparation of novel monomers based on disubstituted cycloalkanones, having a general formula 1 given in the drawing accompanying this specification, where R = nil or - CH2 or CH-CH3, n = 2 to 6, which comprises reacting in an inert atmosphere methacryloyl chloride with 2 - (4-nitro benzylidene) -6-4-[(2-hydroxy ethyloxy) benzylidene] cyclo - alkanones, having a general formula 2 wherein R= nil or -CH2 or CH-CH3, n = 2 to 6, as specified in the drawing accompanying this specification, in a dry polar aprotic solvent, in the presence of a catalyst in the form of trialkylamine, stirring the reaction mixture at a temperature in the range of 25 to 35°C, for a period ranging from 10 to 14 hours, separating the solids by conventional methods such as filtration, washing the filtrate with about 5% v/v aqueous alkali metal hydroxide solution, then with about 2N cold hydrochloric acid and water, drying the organic phase over a drying agent selected from anhydrous sodium sulphate , removing the aprotic solvent under reduced pressure, purifying by conventional methods to obtain the pure product. 2. A process as claimed in claim 1, wherein, the inert atmosphere is maintained by using nitrogen or argon. 3. A process as claimed in claims 1 to 2, wherein catalyst trialkylamine used is preferably selected from triethylamine. 4. A process as claimed in claims 1 to 3, wherein, the polar aprotic solvent used is such as dichloromethane, chloroform, dichloroethane. 5. A process for the preparation of novel monomers based on disubstituted cycloalkanones, substantially described herein with reference to the examples accompanying the specification.

Documents:

1107-del-1998-abstract.pdf

1107-del-1998-claims.pdf

1107-del-1998-correspondence-others.pdf

1107-del-1998-correspondence-po.pdf

1107-del-1998-description (complete).pdf

1107-del-1998-drawings.pdf

1107-del-1998-form-1.pdf

1107-del-1998-form-19.pdf

1107-del-1998-form-2.pdf