A novel and efficient method was developed for the liquid-phase synthesis of Nj,4-disubstitutedbenzodiazepine-2,5-diones with 2-chloro-5-nitrobenzoic acid as initiating material via 4 step reactions containing esterifieation, "Ulmn reaction", acylation, alkylation and cyclization. The reaction conditions were mild and the overall yields of the products ranged from 45% to 71%.
WANG Qiu-yan YU Jing-jun LU Cui-fen CHEN Zu-xing YANG Gui-chun