Title of Invention

"NOVEL BISPHENOL COMPOUND AND A PROCESS FOR PREPARATION THEREOF"

Abstract

The present invention provides a bisphenol compound. The present invention further provides a process for the preparation of bisphenol compounds starting from Cashew Nut Shell Liquid (CNSL); - a renewable resource material. The bisphenols prepared in the present invention can be utilized as difunctional monomers for the preparation of various polymers such as epoxy resins, polyesters, polyethersulfones, polyetherketones, polyetherimides, polyarylates, polycarbonates, etc.

Full Text

FIELD OF THE INVENTION The present invention relates to a novel bisphenol compound and a process for preparation thereof. Particularly the present invention relates to a novel bisphenol compound of formula (I), wherein R1 = R2 or R1 # R2 and R1 and/ or R2 may be hydrogen or methyl. (Formula Removed) More particularly, the present invention relates to synthesis of a compound of formula (I) starting from Cashew Nut Shell Liquid (CNSL), a renewable resource material. BACKGROUND OF THE INVENTION Cashew nut shell liquid (hereinafter sometimes simply "CNSL" for brevity) has been known for years to contain compounds useful in various aspects of chemical industry, with particular reference to plastics production. It is of such interest for various purposes that technical grade CNSL is a commercially available product. It comprises, in major proportion (typically about 80% by weight), a material also sold separately under the trade name CARDANOL which is a mixture of the hydroxyalkenylphenols 3-(pentadec-8-enyl)phenol, 3-(pentadeca-8,11-dienyl)phenol and 3-(pentadeca-8,11,14-trienyl)phenol. Minor constituents include about.18% of a material also sold separately under the trade name CARDOL, which is a mixture of the 5-substituted resorcinols, and about 2% 2-methylcardol, which is a mixture of the corresponding 2-methyl-5-substituted resorcinols, and other materials not fully identified. Bisphenols have been extremely useful chemicals for many decades. As difunctional monomers, they have been used in the preparation of various polymers, such as epoxy resins, polyesters, polyethersulfones, polyetherketones, polyetherimides, polyarylates and, in particular, polycarbonates. It is well known in the art that incorporation of a long alkyl chain in polymer backbone imparts properties such as increase in the segmental mobility, solubility and hence it improves processability of the material. The use of bisphenols having long chain aliphatic substituent as a comonomer is known to offer polymer material with high flow and improved impact resistance. It is therefore of great interest and importance to synthesise new bisphenols with alkyl radical in their structure having the potential of affording polymer material with high processability and impact strength. It is of particular interest to develop bisphenols, which may be easily and cheaply obtained from readily available and renewable resource material such as CNSL. There is no prior art available for the preparation of bisphenols disclosed herein and inventors of the present invention are reporting the said compounds for the first time. OBJECTIVES OF THE INVENTION The main object of the present invention is to provide a novel bisphenol compound of formula (I). Another object of the invention is to provide a class of novel bisphenol compounds starting from naturally occurring renewable material; CNSL. Yet another object of the invention is to provide a process for the preparation of a novel bisphenol compound of formula (I). SUMMARY OF THE INVENTION Accordingly the present invention provides a bisphenol compound of formula (I) (Formula Removed) wherein R1 = R2 or R1 # R2 and R1 and/ or R2 is hydrogen or methyl and the compound is selected from 1,1,1-[bis(4-hydroxyphenyl)-4'- pentadecylphenyl] ethane and 1,1,1-[bis(3-methyl-4-hydroxyphenyl)-4'-pentadecylphenyl] ethane. The present invention further provides a process for the preparation of a bisphenol compound of formula (I), (Formula Removed) wherein R1 = R2 or R1 # R2 and R1 and/ or R2 is hydrogen or methyl, the said process comprising the steps of: a) dehydroxylating 3-pentadecyl phenol of formula (II) (Formula Removed) by reacting 3-pentadecyl phenol of formula (II) with 1-phenyl-5-chlorotetrazole of formula (III) (Formula Removed) in presence of a weak base in acetone, refluxing the reaction mixture for at least 16 hours, removing the solvent by a known method and pouring the resultant concentrate in water to precipitate the compound, followed by recrystallization in alcohol to obtain 3-pentadecyl-1-(1-phenyl-tetrazolyloxy)phenyl of formula (IV), (Formula Removed) b) hydrogenolysing 3-pentadecyl-1-(1-phenyl-tetrazolyloxy)phenyl of formula (IV) obtained from step (a) in a Parr reactor, in the presence of about 5% palladium-on-charcoal, in an aromatic hydrocarbon solvent, at a pressure of about 40 p.s.i., at a temperature in the range of 35-40°C for atleast 8 hours, filtering the above said reaction mixture and washing the insoluble residue with hot alcohol, combining the above said filtrates and concentrating the combined filtrate by removing the solvent by known method to obtain a sticky residue, extracting the above said residue with toluene and washing it with an aqueous metal hydroxide and then again by water, followed by removal of solvent by known method to obtain pentadecyl benzene of formula (V), as a faint yellow liquid, (Formula Removed) c) acetylating pentadecyl benzene of formula (V) obtained from step ( b) with an acetylating agent, in the presence of a Lewis acid catalyst, in an organic solvent, at a temperature below 5°C, for a period of at least about 2 hours, warming the above reaction mixture to a temperature of 30-40°C, for at least 5-6 hours, pouring the above said reaction mixture in ice and extracting the resultant compound with a halocarbon solvent, washing the above said extracts with dilute hydrochloric acid and then again by water, followed by removal of solvent by known method to obtain 4-acetyl pentadecyl benzene of formula (VI), (Formula Removed) d) reacting 4-acetyl pentadecyl benzene of formula (VI) obtained from step (c) with substituted or unsubstituted phenol, in the presence of an acidic catalyst, at a temperature in the range of 30- 50°C, for a period of about 4 days, dissolving the above said reaction mixture in ethyl acetate and subsequently washing it with an aqueous solution of a weak base and water, respectively, removing the solvent and purifying the resultant product by known method to obtain the desired bisphenol compound of formula (I). In an embodiment of the present invention the weak base used is selected from potassium carbonate and sodium carbonate. In yet another embodiment the alcohol used is selected from methanol and ethanol. In yet another embodiment the aromatic hydrocarbon solvent used in hydrogenolysis in step (b) is selected from toluene and benzene. In yet another embodiment the acetylating agent used in step (c) is selected from the group consisting of acetic acid, acetic anhydride and acetyl chloride. In yet another embodiment the metal hydroxide used is an alkali metal hydroxide selected from sodium hydroxide and potassium hydroxide. In yet another embodiment the Lewis acid catalyst used in step (c) is selected from AlCI3 and BF3. In yet another embodiment the organic solvent used for acetylation in step (c) is selected from halogenated hydrocarbon and nitrogen compound. In yet another embodiment the halogenated hydrocarbon solvent used is selected from dichloromethane and chloroform. In yet another embodiment the nitrogen compound used as an organic solvent is selected from nitro methane and nitro benzene. In yet another embodiment the acid catalyst used in phenol condensation in step (d) is selected from acidic clays, sulfated zirconia, 3-mercaptopropionic acid, glacial acetic acid, hydrogen chloride and a mixture thereof. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel bisphenol compounds useful as difunctional monomers for the synthesis of various high performance polymers. The bisphenol compounds of the present invention can be represented as formula (I), (Formula Removed) wherein R1 and R2 are identical or different and independently at each occurrence represents hydrogen or methyl. Preparation of bisphenol compounds of formula I comprises of three steps, viz., Step A, B and C. Scheme (I) (Scheme Removed) Step A of the method of the invention comprises dehydroxylation of 3-pentadecyl phenol to obtain pentadecyl benzene. The replacement of phenolic hydroxyl group by hydrogen is an important organic transformation. Several methods are available for dehydroxylation such as, use of: cyclohexene/ Pd/C/AICI3 (Synthesis, 1978, 397), HI/CH3COOH (J. Org. Chem., 1979, 44, 26, 4813), NaBH4/NiCI2 (J. Chem. Soc. Perkin Trans. I, 1992, 1897), 1-phenyl-5-chlorotetrazole/ [H] / Pd-C (J. Am. Chem. Soc., 1966, 88, 4271). Phenolic hydroxyl group can be replaced by hydrogen in two steps: conversion of phenol to ether followed by cleavage with an alkali metal in liquid ammonia. (J. Org. Chem., 1973, 38, 13, 2314; J. Org. Chem., 1964, 29, 3124; J. Org, Chem., 1966, 31, 1662), (J. Am. Chem. Soc., 1937, 59, 603; J. Am. Chem. Soc., 1937, 59, 1488,; J. Am. Chem. Soc., 1938, 60, 94). A traceless perfluoroalkylsulfonyl (PFS) linker was reported for the deoxygenation of phenols (Org. Lett., 2001, 3, 17, 2769). In Step A of the process of preparation of pentadecyl benzene, the use is made of 1-phenyl-5-chlorotetrazole for etherification reaction with 3-pentadecyl phenol, followed by catalytic hydrogenolysis being most preferred; among the methods available for dehydroxylation of phenol. In present invention, the process for the preparation of 3-pentadecyl-1-(1-phenyl-tetrazolyloxy)phenyl, comprises reaction of 3-pentadecyl phenol with 1-phenyl-5-chlorotetrazole in presence of potassium carbonate as a base and acetone as a solvent, refluxing temperature is necessary in the duration of 16-18 hours for complete etherification reaction. The amount of potassium carbonate is double over stoichiometric amount of substrate. In catalytic hydrogenolysis step, while subjecting 3-pentadecyl-1-(1-phenyl-tetrazolyloxy)phenyl to hydrogenolysis, the catalyst 5% palladium-on-charcoal is most preferred, with a proportion of 20%-40% by weight, pressure of 40-60 p.s.i., and temperature in the range of 35-40°C being most preferred.. Step B of the method of the invention comprises acetylation of pentadecyl benzene of formula II with acetyl chloride selectively at para-position using a Lewis acid catalyst., under classical acetylation reaction conditions. U.S. Pat. No. 4,663,484 describes acetylation of aromatics. Suitable conditions for acetylation are described in J. Am. Chem. Soc. 1999, 121, 2657-2661. Usable examples of acetylating agents can include acetic acid, acetic anhydride and acetyl chloride, with acetyl chloride being particularly preferred. The acetylating agent may be used preferably in a proportion from 1 to 1.5 moles per mole of pentadecyl benzene, with 1 to 1.2 moles being more preferred. The Lewis acid catalysts used in acetylation reaction are generally AlCh or BF3 The acetylation reaction in step A may preferably be conducted in a solvent. In general, it is possible to use any one of the solvents, which are typically employed for acetylation of aromatic compounds. Usable examples can include any organic halogen compounds such as dichloromethane, chloroform and nitro compounds such as nitromethane, nitrobenzene. However, use of halocarbon solvents such as dichloromethane, chloroform is preferred. Preferably acetylation reaction is conducted in a nitrogen atmosphere. The reaction can be effected in a temperature range of from 0°C to 40°C to attain selectivity and better yield. The yields from this reaction are virtually quantitative and the quality of acetylated 4-pentadecyl benzene is such that it can be directly used for phenol condensation reaction. Step C of the present invention comprises reacting 4-acetyl pentadecyl benzene, under reaction producing conditions, with a phenolic compound, substituted or unsubstituted one. Such conditions include presence of an acidic catalyst, as illustrated by ion exchange resins in the acid form, acidic clays, sulfated zirconia and excess hydrogen chloride, the later preferably used in combination with a meracaptan such as 3-mercaptopropionic acid. U.S. Pat. Nos. 6,255,439; H1943H describe methods of phenol condensation reaction with carbonyl compound for bisphenol synthesis, the disclosures of which are incorporated by reference herein. For the phenol condensation reaction temperatures in the range of about 10°C-50°C are typical. The intermediates and product formed in each step A-B-C may be worked up and isolated by conventional means. These may include solvent removal, when solvent is employed, washing, drying and recrystallisation. The following examples describe the invention in details, which are illustrative only and should not be construed to limit the scope of the present invention in any manner. EXAMPLE I This example illustrates synthesis of 3-pentadecyl-1-(1-phenyl-tetrazolyloxy)phenyl. A 500-ml., round-bottomed flask fitted with an efficient condenser and a magnetic stirring bar was charged with 3-pentadecyl phenol (25 g, 82 mmol), 1-phenyl-5-chlorotetrazole (14.82 g, 82 mmol), anhydrous potassium carbonate (22.69 g, 164.1 mmol) and 250 ml acetone. The mixture was stirred and heated under reflux for 18 hours. After cooling, the reaction mixture was concentrated; 100 ml water was added and cooled overnight at 5 °C. The solid obtained was collected by filtration and dried in air, giving a crude product, which was then dissolved in 100 ml hot methanol. The solution was filtered while hot to remove small amount of insoluble material and cooled in ice, yielding 3-pentadecyl-1-(1-phenyl-tetrazolyloxy)phenyl as a white solid. The yield obtained was 26 g. (70% of the theoretical). EXAMPLE II This example illustrates synthesis of pentadecyl benzene. Into a solution of 3-pentadecyl-1-(1-phenyl-tetrazolyloxy)phenyl (20 g, 44.5 mmol) in 200 ml toluene was added palladium-on-charcoal (4 g, 20% by weight), and the mixture was shaken with hydrogen in a Parr apparatus at 40 p.s.i. and 40°C for 8 hours. The mixture was filtered, and the insoluble residue was washed with hot ethanol (3 x 100 ml). The filtrates were combined, and concentrated, leaving a sticky residue, which was dissolved in 200 ml toluene, shaken with 100 ml of 10% aqueous sodium hydroxide solution, and the layers were separated. The aqueous layer was again extracted with 100 ml toluene. After combining, organic layer was washed with water and dried over sodium sulfate. Removal of toluene yielded crude pentadecyl benzene, which was then purified by column chromatography. Pure pentadecyl benzene was obtained in a yield of 11 g. (85% of the theoretical). EXAMPLE III This example illustrates synthesis of 4-acetyl pentadecyl benzene. A 500-ml-three-necked round-bottomed flask, with an efficient cooling was charged with aluminium chloride (5.82 g, 43.67 mmol) and dichloromethane (100 ml). Acetyl chloride (3.42 g, 43.67 mmol) was added to the vigorously stirred reaction mixture over a period of 15 minutes. Pentadecyl benzene (10 g, 34.66 mmol) was added over a period of 30 minutes; the clear solution was stirred at 0°C for 2 hours and allowed to warm to room temperature. The reaction mixture was poured in ice and extracted with dichloromethane (3 x 100 ml), the combined organic layers was washed with 1 N hydrochloric acid (2 x 30 ml) and water (3 x 50 ml), dried over sodium sulfate and the solvent was evaporated to obtain 4-acetyl pentadecyl benzene as a low melting faint yellow solid. The yield was 10 g (87% of theoretical). EXAMPLE IV This example illustrates synthesis of 1,1,1-[bis(4-hydroxyphenyl)-4'-pentadecylphenyl] ethane. A 250-ml-three-necked round-bottomed flask fitted with a magnetic stirrer and gas dip tube was charged with 4-acetyl pentadecyl benzene (5 g, 15.15 mmol), phenol (8.54 g, 90.90 mmol) and 0.13 ml of 3-mercaptopropionic acid. The resulting mixture was stirred at room temperature for 15 minutes, after which anhydrous hydrogen chloride gas was bubbled into the reaction mixture for 4 days at 50°C, whereupon the mixture solidified. The reaction mixture was dissolved in ethyl acetate (500 ml), washed with aqueous sodium bicarbonate (3 x 100 ml) solution and water (3 x 100 ml), layers separated and dried over sodium sulfate. Vacuum stripping of solvent afforded a pink solid, which was purified by column chromatography. The desired 1,1,1-[bis(4-hydroxyphenyl)-4'-pentadecylphenyl] ethane was obtained in a yield of 4 g (52% of theoretical). EXAMPLE V This example illustrates synthesis of 1,1,1-[bis(3-methyl-4-hydroxyphenyl)-4'-pentadecylphenyl] ethane. A 250-ml-three-necked round-bottomed flask fitted with a magnetic stirrer and gas dip tube was charged with p-acetyl pentadecyl benzene (5 g, 15.15 mmol), o-cresol (9.83 g, 90.90 mmol) and 0.13 ml of 3-mercaptopropionic acid. The resulting mixture was stirred at room temperature for 15 minutes, after which anhydrous hydrogen chloride gas was passed in to mixture for 4 days at 50°C, whereupon the mixture solidified. The reaction mixture was dissolved in ethyl acetate (500 ml), washed with aqueous sodium bicarbonate (3 x 100 ml) solution and water (3 x 100 ml), and dried over sodium sulfate. Vacuum stripping of solvent afforded a pink solid, which was purified with column chromatography. The desired 1,1,1-[bis(3-methyl-4- hydroxyphenyl)-4'-pentadecylphenyl] ethane was obtained in a yield of 4 g (50% of theoretical). ADVANTAGES OF THE INVENTION The present invention provides novel bisphenol compounds with alkyl radical in their structure, which has the potential to be utilized as difunotional monomers for the preparation high performance polymers with excellent processability by virtue of the presence of pentadecyl chain. The present invention also provides a simple and economical procedure for the synthesis of novel bisphenol compounds since it uses CNSL as the starting material, which is a naturally occurring and renewable resource material. It may become apparent to those skilled in the art that various changes and modifications may be made herein without departing from the invention and it is intended in the appended claims to cover such changes and modifications as fall within the true spirit and scope of the invention. We claim: 1. A bisphenol compound of formula (I) (Formula Removed) wherein R1 = R2 or R1 # R2 and R1 and/ or R2 is hydrogen or methyl and the compound is selected from 1,1,1-[bis(4-hydroxyphenyl)-4'- pentadecylphenyl] ethane and 1,1,1-[bis(3-methyl-4-hydroxyphenyl)-4'-pentadecylphenyl] ethane. 2. A process for the preparation of a bisphenol compound of formula (I), (Formula Removed) wherein R1 = R2 or R1 # R2 and R1 and/ or R2 is hydrogen or methyl, the said process comprising the steps of: a) dehydroxylating 3-pentadecyl phenol of formula (II) (Formula Removed) by reacting 3-pentadecyl phenol of formula (II) with 1-phenyl-5-chlorotetrazole of formula (III) (Formula Removed) in presence of a weak base in acetone, refluxing the reaction mixture for at least 16 hours, removing the solvent by a known method and pouring the resultant concentrate in water to precipitate the compound, followed by recrystallization in alcohol to obtain 3-pentadecyl-1-(1-phenyl-tetrazolyloxy)phenyl of formula (IV), b) hydrogenolysing 3-pentadecyl-1-(1-phenyl-tetrazolyloxy)phenyl of formula (IV) obtained from step (a) in a Parr reactor, in the presence of about 5% palladium-on-charcoal, in an aromatic hydrocarbon solvent, at a pressure of about 40 p.s.i, at a temperature in the range of 35-40°C for atleast 8 hours, filtering the above said reaction mixture and washing the insoluble residue with hot alcohol, combining the above said filtrates and concentrating the combined filtrate by removing the solvent by known method to obtain a sticky residue, extracting the above said residue with toluene and washing it with an aqueous metal hydroxide and then again by water, followed by removal of solvent by known method to obtain pentadecyl benzene of formula (V), as a faint yellow liquid, (Formula Removed) c) acetylating pentadecyl benzene of formula (V) obtained from step ( b) with an acetylating agent, in the presence of a Lewis acid catalyst, in an organic solvent, at a temperature below 5°C, for a period of at least about 2 hours, warming the above reaction mixture to a temperature of 30-40°C, for at least 5-6 hours, pouring the above said reaction mixture in ice and extracting the resultant compound with a halocarbon solvent, washing the above said extracts with dilute hydrochloric acid and then again by water, followed by removal of solvent by known method to obtain 4-acetyl pentadecyl benzene of formula (VI), (Formula Removed) d) reacting 4-acetyl pentadecyl benzene of formula (VI) obtained from step (c) with substituted or unsubstituted phenol, in the presence of an acidic catalyst, at a temperature in the range of 30- 50°C, for a period of 4 days, dissolving the above said reaction mixture in ethyl acetate and subsequently washing it with an aqueous solution of a weak base and water, respectively, removing the solvent and purifying the resultant product by known method to obtain the desired bisphenol compound of formula (I). 4. A process as claimed in claim 2, wherein the weak base used is selected from potassium carbonate and sodium carbonate. 5. A process as claimed in claim 2, wherein the alcohol used is selected from methanol and ethanol. 6. A process as claimed in claim 2, wherein the aromatic hydrocarbon solvent used in hydrogenolysis in step (b) is selected from toluene and benzene. 7. A process as claimed in claim 2, wherein the acetylating agent used in step (c) is selected from the group consisting of acetic acid, acetic anhydride and acetyl chloride. 8. A process as claimed in claim 2, wherein the metal hydroxide used is an alkali metal hydroxide selected from sodium hydroxide and potassium hydroxide. 9. A process as claimed in claim 2, wherein the Lewis acid catalyst used in step (c) is selected from AICI3 and BF3. 10. A process as claimed in claim 2, wherein the organic solvent used for acetylation in step (c) is selected from halogenated hydrocarbon and nitrogen compound. 11. A process as claimed in claim 10, wherein the halogenated hydrocarbon solvent used is selected from dichloromethane and chloroform. 12. A process as claimed in claim 10, wherein the nitrogen compound used as an organic solvent is selected from nitro methane and nitro benzene. 13. A process as claimed in claim 2, wherein the acid catalyst used in phenol condensation in step (d) is selected from acidic clays, sulfated zirconia, 3-mercaptopropionic acid, glacial acetic acid, hydrogen chloride and a mixture thereof.

Documents:

2600-DEL-2005-Abstract-(06-01-2012).pdf

2600-del-2005-abstract.pdf

2600-DEL-2005-Claims-(06-01-2012).pdf

2600-del-2005-claims.pdf

2600-DEL-2005-Correspodence Others-(06-01-2012).pdf

2600-DEL-2005-Correspondence Others-(10-01-2012).pdf

2600-DEL-2005-Correspondence Others-(27-01-2012).pdf

2600-DEL-2005-Correspondence-Others-(23-03-2010).pdf

2600-del-2005-correspondence-others.pdf

2600-DEL-2005-Description (Complete)-(06-01-2012).pdf

2600-del-2005-description (complete).pdf

2600-del-2005-form-1.pdf

2600-del-2005-form-18.pdf

2600-del-2005-form-2.pdf

2600-DEL-2005-Form-3-(06-01-2012).pdf

2600-DEL-2005-Form-3-(23-03-2010).pdf

2600-del-2005-form-3.pdf

2600-del-2005-form-5.pdf

2600-DEL-2005-Petition-137-(10-01-2012).pdf

2600-DEL-2005-Petition-137-(27-01-2012).pdf