Acylation products of <i>N</i>‐acyllactams and their activation effect in the anionic polymerization of lactams

Abstract

Abstract Benzoylation of metalated N ‐benzoyllactams, derived from 7‐, 9‐ and 13‐membered lactams, gives rise to both N ‐benzoylenol esters ( 1 ) and N ,2‐dibenzoyllactams ( 3 ), whereas in the case of derivatives of 5‐ and 6‐membered lactams only products 3 by C ‐acylation in position 2 were isolated. In the propionylation of N ‐benzoyl‐ or N ‐propionyl‐6‐hexanelactam, only products of O ‐acylation were formed. The aminolysis of 3 gave rise to 2‐benzoyllactams ( 4 ). For selected compounds of type 1–4 the activation effect in the anionic polymerization of 6‐hexanelactam was found to be comparable with that of N ‐acyllactams. The equilibrium acidities in DMSO were measured for 3 and 4 .