SYNTHESIS OF HETEROBIFUNCTIONAL CROSS-LINKING REAGENTS - OMEGA-(N-MALEIMIDO)ALKANOIC ACID HYDRAZIDES

omega-(N-Maleimido)alkanoic acid hydrazides (6a-c) with C-11, C-7 and C-5 alkyl arms have been synthesized by novel method. Tile method invo lves tile reaction between maleic anhydride and omega-aminoalkanoic ac ids (2) to get maleamic acids (3) which are in turn cyclized to omega- (N-maleimido)alkanoic acids (4) using fused sodium acetate and acetic anhydride. These maleimidoalkanoic acids are activated and then conver ted in situ into their N-2-t-Lutyloxycarbonyl hydrazides (5) from whic h the t-butyl-based protecting group is cleaved without damage to the maleimide moiety to obtain the title compounds.