In our research group we have been using bismaleamicacid to synthesize the bismaleimide as potential precursors for the synthesis of polymer bond reaction with Bovarian Serum Albumen for bioconjugate studies of peptides polymers . In order to obtain the bismaleimide we are exploring various kind of dehydrating agents, in one of the reactions we treated the bis maleimidic acid2 (1a) with EDC in dichloromethane, to our surprise the reaction mixture is very clear within 10-15 minutes from suspension, and we got the regioselective bis isomaleimide , 1b in quantitative yields. To test this methodology, we treated the 1a with EDC in various solvents. In DMF, the reaction is time is 20 minutes and yield are less and required purification.