Patent ID: 6590108
Filing Date: 2003-07-08
Classification: C08G

Abstract:
A method for the synthesis of a dianhydride, comprising transimidation of a bis(imide) (IV) wherein the alkyl is moiety is a straight or branched chain alkyl group having from 1 to about 18 carbon atoms, and S is a divalent radical selected from the group consisting of a straight or branched chain alkylene group having from about 2 to about 20 carbon atoms, a cycloalkylene group having from about 3 to about 20 carbon atoms, and an arylene group having from 6 to about 20 carbon atoms in the presence of a substituted phthalic anhydride having a substituent selected from the group consisting of nitro, bromo, fluoro and chloro, to yield a dianhydride (V)