Title of Invention

"AN IMPROVED PROCESS FOR THE PREPARATION OF BIS (HALO- NAPHTHALIMIDO) ALKYLENES"

Abstract

This invention relates to an improved process for the preparation of bis (halonaphthalimido) alkylenes. The process relates to the preparation of bis(4-halo-l, 8-naphthalimido) alkylenes having general formula 1 given in the drawing accompanying the specification wherein R = -(CH2)n - n = 2 to 12 and x = halogen. Bis (4-halo-l, 8-naphthalineimido) compounds prepared by the process of this invention can be used to prepare high performance engineering polymers with good chemical and thermal stability. Suitable for the synthesis of soluble high performance polymer by nucleophilic halo displacement polymerization reaction offering advantages of ease of operation and leading to improved yields as well. The process does not require the dioxan or toluene reflux as reported earlier. The process of this invention is amenable for scale up operation.

Full Text

This invention relates to an improved process for the preps ration of bis(halonaphthalimido) alkylenes. More particularly, it relates to s. process for the preparation of bis (4-halo-1 , B-naph-t h a 1 i m i d a ) a 1 k y i e n e s having Q e n e r a 1 f o r m u 1 a 1 give n i n t h e d r a w •••- ing accompanying this specification wherein R •-• -CCH ) •••- 2 n n ~: 2 to 12 and X= halogen. 13is (4-hal o-l , S-naph thai ene imido ) compounds prepared by the process of this invention can be used to p repa re high perfo rman ce e ngi neering po1y mers wi t h Q ood c h e m i c: a 1 a n d the r m a 1 s t a b i 1 i t y . The synthesis of polymers with various specific properties such as high glass transition temperature, improved Drocessabi1ity, and long term thermal stability is still major driving force for development o f new monomers. B i s(nap h t h a1i m ido) based polymers will have high chemical and thermal stability, and h i g h s o 1 u b i 1 i t y as camp a r e d t o t h o a e p r e p a r e d w i t; h b i s (p h t h a 1 i m i d o ) polymer s . T hi e p o 1 y m e r s s y n t h e s i s e d u s i n g the compounds prepared by the process of this invention would be obtained by nuc1eophi1ic halo displacement polymerisation reaction. One example would be polythioarylene copolymers, p o 1. y (4- t h i o p IT e n y 1 e n e ) b e i n g a n i m p o r t a n t member- in the fa m i 1 y of p o i y t h i o a r y 1 e n e s . In the conventional synthetic: route to the synthesis of poiythioarylenes, the polymer precipitates out of the system as soon as a critical molecular weight is achieved leading to a restriction in the molecular weight. If the compounds prepared by the process of the present invention are used as monomers, since the polymer is soluble, precipitation during the course of the polymerization does not occur and high molecular weight polymers can be obtained. Another advantage is the presence of imide ring which would help in easy displacement of halo group so as to result in high molecular weight polythioarylene copolymer. The methylene spacer will help in enhanced solubility, while rigid naphthalene ring would lead to polymers with good thermal and mechanical stability. i The known method of preparation of bis(halonaphthalimido) compounds namely bis(4-halo-l,8-naphthalimido)alkylene reported hitherto in the literature involves : (i) the use of dioxan giving yields in the range of 58 % as described in a report U S. patent 5554622 by BAYER AG, Germany in 1994. The reaction scheme involved the use of 1,8-naphthalic anhydride with N.N'-bis(2-aminoethyl)-1,3-diaminopropane in dioxan with the primary objective of the use of this material for anti-tumor activity. (ii) Yamada et.al., reported in Japanese patent 900328 (1991) reaction of 4-chloro naphthalic anhydride and hexamethylene diamine in N-methyl pyrrolidone and the use of tolune at temperature of 160°C . However it has been reported by Danuta Sek et. al. [J.Poly.Sc., Part A, Poly. Chem. Ed., 33, 547, (1995)] that the use of N-methyl pyrrolidone could lead to the formation of isoimide which is an undesired product. Isoimide has less thermal stability compared with imides. Also amine reacts with halogens, instead of anhydride in N-methyl pyrrolidone. The present process offers quantitative selective synthesis of imides only (without the formation of isoimides, protecting the halogen). The main object of the present invention is therefore to provide an improved process for the preparation of bis (halo-naphthalimido) alkylenes which are suitable forth synthesis of soluble high performance polymer by nucleophilic halo displacement polymerization reaction offering advantages of ease of operation and leading to improved yields as well. Accordingly, the present invention provides an improved process for the preparation of bis(halo-naphthalimido) alkylene of formula 1 wherein R = (CH2)n -n = 2 to 12 and X is halogen of the drawing accompanying the specification which comprises, reacting in an inert atmosphere 4-halo-1, 8-naphthalic anhydride and an aliphatic diamine such as herein described in a ratio of 1.5:1 to 5:1 (w/w) in a polar aprotic solvent such as herein described and in the presence of a catalyst such as herein described at a temperatures in the range of 110 to 250°C for a period ranging from 6 to 15 hours, cooling the reaction mixture to ambient temperature, pouring the reaction mixture into an alkanol, as herein described, separating the product by conventional methods, washing with alkanol as defined above to remove the unreacted material and the by products formed during reaction followed by drying to get the final product, Bis (halo-naphthalimido) alkylene. In an embodiment of the present invention, the inert gas used may be such as nitrogen, argon. In another embodiment of the invention, the 4-halo-1,8-napthalene anhydride used may be such as 4-chloro-l,8-naphthalic anhydride, 4-bromo-1,8-naphthalic anhydride. In still another embodiment of the invention, the catalyst used may be such as benzoic acid, isoquinoline, pyridine, quinoline or mixtures of them. In yet another embodiment of the invention, the aliphatic diamines used may be such as 1,2-ethylenediamine, 1,3-propylenediamine, 1,6-hexamethylenediamine, 1,12-dodecyldiamine. In still another embodiment of the present invention, the aprotic solvent used may be such as m-cresol, acetic anhydride preferably m-cresol. In yet another embodiment of the invention, the alkanol used may be such as methanol, ethanol. The process of the present invention is described with reference to following examples which are illustrative only and should not be construed to limit the scope of this invention in any manner. Example 1 2.23 g of 4-chloro-l,8-naphthalic anhydride was dissolved in 20 ml m-cresol under nitrogen atmosphere. 1.21 g of 1,12 dodecyl diamine and 0.1 g of isoquinoline were added to the above solution. The reaction mixture was heated to 210°C for 8 hours. At the end of 8 hours, the mixture was cooled to room temperature, and poured in methanol. The product was filtered, washed with hot methanol to remove by-products and unreacted materials and dried. The yield obtained was 3.00 g (93 %) . The IR spectra using a KBr pellet showed the following absorptions : 1701 cm-1; 1669 cm-1 imide group; 760 cm-1 C-Cl group. Example 2 2.23 g 4-chloro-l,8-naphthalic anhydride was dissolved in 30 ml acetic anhydride under argon atmosphere. 0.60 g of 1,2 ethylene diamine, and 0.15 g of quinoline were added to the above solution. The reaction mixture was heated to 180°C for 9 hours. After 9 hours of reaction time the mixture was cooled to room temperature, and precipitated in ethanol. The product was filtered, washed with hot ethanol to remove by-products and unreacted materials, and dried. The yield obtained was 2.50 g (89 %) . The IR spectra using a KBr pellet showed the following absorptions : 1702 cm-1; 1668 cm-1 imide group; 764 cm-1 C-Cl group. Example 3 2.23 g 4-chloro-l,8-naphthalic anhydride was dissolved in 35 ml m-cresol under nitrogen atmosphere. 1.00 g of 1,6-hexamethylenediamine and 0.1 g of benzoic acid 0.1 g of pyridine ware addod to the abova ouluLiou. Tha rottotion mixtion was heated to 160°C for 10 hours. After completion of reaction "the mixture was cooled to room temperature, and precipitated in methanol. The product was filtered, washed with hot methanol to remove by¬products and unreacted materials and dried The yield obtained was 3.10 g (95 %) The IR spectra using a KBr pellet showed the following I absorptions : , 1703 cm-1; 1663 cm-1 imide group; 758 cm-1 C-C1 group. Example 4 3.68 g 4-bromo-l,8-rfaphthalic anhydride was dissolved in 25 ml m-cresol under argon atmosphere. 1.00 g of 1,6-hexamethylenediamine and 0.10 g of benzoic acid 0.10 g of isoguinoline were added to the above solution. The reaction mixture was heated to 200°C for 8 hours. After completion of reaction the mixture was cooled to room temperature, and precipitated in ethanol. The product was filtered, washed with hot ethanol to remove by-products and unreacted materials and dried The yield obtained was 4.50 g (93 %) . The IR spectra using a KBr pellet showed the following absorptions : 1705 cm-1; 1668 cm-1 imide group; 768 cm-1 C-C1 group. Example 5 3.68 g 4-bromo-l,8-naphthalic anhydride was dissolved in 30 ml m-cresol under nitrogen atmosphere. 0.74 g of 1,3-propylenediamine and 0.1 g of benzole acid & 0.15g of quinoline were added to the above solution. The reaction mixture was heated to 110°C for 15 hours. After completion of reaction the mixture was cooled to room temperature, and precipitated in methanol. The product was filtered, washed with hot methanol to remove by products and unreacted materials, dried and characterised. The yield obtained was 4.45 g (91 %). The IR spectra using a KBr pellet showed the following absorptions : 1708 cm-1; 1665 cm-1 imide group; 749 cm-1 C-C1 group. Advantages of the present invention : 1. The process does not require the dioxan or toluene reflux as reported earlier. 2. The process of this invention is amenable for scale up operation. 3. The compounds can be used as monomers or comonomers for the preparation of high performance polymers by nucleophilic halo displacement polymerisation reaction without further purification. 4. Reasonably high yields are obtained. 5. Formation of isoimide, an undesired product is eliminated protecting the halogen. We Claim: 1. An improved process for the preparation of bis(halo-naphthalimido) alkylene of formula 1 wherein R = (CH2)n -n = 2 to 12 and X is halogen of the drawing accompanying the specification which comprises; reacting in an inert atmosphere, 4-halo-l, 8-naphthalic anhydride and an aliphatic diamine such as herein described in a ratio of 1.5:1 to 5:1 (w/w) in a polar aprotic solvent such as herein described and in the presence of a catalyst such as herein described at a temperatures in the range of 110 to 250°C for a period ranging from 6 to 15 hours, cooling the reaction mixture to ambient temperature, pouring the reaction mixture into an alkanol such as herein described, separating the product by conventional methods, washing with alkanol as defined above to remove the unreacted material and by prodcuts formed during reaction followed by drying to get the final product bis (halo-naphthalimido) alkylene. 2. An improved process as claimed in claim 1, wherein, the inert gas used is selected from nitrogen, argon. 3. An improved process as claimed in claims 1 and 2, wherein the 4-halo-l,8-naphthalic anhydride used is selected from 4-chloro-l,8-naphthalic anhydride, 4-bromo-l, 8- naphthalic anhydride. 4. An improved process as claimed in claims 1 to 3, wherein the catalyst used is selected from benzoic acid, isoquinoline, pyridine, quinoline or mixtures of them. 5. An improved process as claimed in claims 1 to 4, wherein the aliphatic diamines used is selected from 1,2-ethylenediamine, 1,3-propylenediamine, 1,6-hexamethylene-diamine, 1,12-dodecy Idiamine. 6. An improved process as claimed in claims 1 to 5, wherein the polar aprotic solvents used is selected from m-cresol, acetic anhydride, preferably m-cresol. 7. An improved process as claimed in claims 1 to 6, wherein the alkanol used is selected from methanol, ethanol. 8. An improved process for the preparation of bis(halo naphthalimido) alkylene having general formula 1 given in the drawing accompanying this specification as substantially described with reference to the examples.

Documents:

3323-del-1998-abstract.pdf

3323-del-1998-claims.pdf

3323-del-1998-correspondence-others.pdf

3323-del-1998-correspondence-po.pdf

3323-del-1998-description (complete).pdf

3323-del-1998-drawings.pdf

3323-del-1998-form-1.pdf

3323-del-1998-form-19.pdf

3323-del-1998-form-2.pdf