Abstract Reactions of N-aryl-and N-methyl-amidines and-amides of α-amino acids with RPCl 2 afford 4-aryl (methyl) imino and 4-oxo-1, 3, 2-diazaphospholanes. 4-Phenylimino-1, 3, 2- diazaphosphorinane was obtained in a similar way by the interaction of N (1), N (2)-diphenyl- β-anilinoisobutyramidine with PhPCl 2.