N-halogenoamidines. Part 1. Amino-imidazolines and -imidazoles from N-chloro-N′-arylamidines and enamines

Abstract

The reaction between N-chloro-N′-arylamidines and enamines derived from aldehydes affords 4-amino-4,5-di-hydro-imidazoles and/or -imidazoles. Imidazole-ring formation was not observed with enamines from ketones and from aldehydes bearing two alkyl groups in the β-position. In the former case chlorinated enamines were obtained, and in the latter a rearrangement to N-(2-amino-2,2-dialkyl)ethylidene-amidines was observed. The reaction mechanism is discussed.