The effect of ring size in N-benzoyl saturated heterocyclic amides

Abstract

The structures of the N-benzoyl derivatives of aziridine, azetidine, pyrrolidine, piperidine, hexamethyleneimine and heptamethyleneimine in solution have been investigated by ¹³C n.m.r. spectroscopy. In conjunction with literature crystal structure and dynamic intramolecular exchange data, it has been concluded that N-benzoylaziridine and N-benzoylazetidine possess pyrimidal nitrogen atoms in solution. The N-benzoyl derivatives of pyrrolidine,  piperidine, hexamethyleneimine and heptamethyleneimine have planar or near planar nitrogen atoms.