Patent ID: 7425650
Filing Date: 2008-09-16
Classification: C07C,C07D,C08G

Abstract:
1. Process for preparing asymmetrical tetracarboxylic acids which comprises cross-coupling a compound selected from the group consisting of: with a compound selected from the group consisting of in the presence of catalysts and additives to obtain a coupled intermediate having a formula selected from the group consisting of: wherein R is nil, CH 2 or C═O, R′ is a low alkyl group, Y is (OH) 2 or (OR′) 2 , Z is oxygen or nitrogen, X is selected from the group consisting of a halogen, OSO 2 CF 3 , and OSO 2 CH 3 , and B is boron; subsequently converting said intermediate to obtain tetracarboxylic acid selected from the group consisting of: