Investigations in the imidazole series

Abstract

The reaction of 2-mercaptonaphth[1,2-d]imidazole with chloroacetaldehyde, bromoacetaldehyde, and α-bromopropionaldehyde diethylacetals leads to the formation of (naphth[1,2-d]-2-mercaptoimidazolyl)acetaldehyde and α-(naphth[1,2-d]-2-mercaptoimidazolyl)propionaldehyde which in the solid state exist as tautomeric forms — 3-hydroxy derivatives of naphth[1,2-d]-imidazo[3,2-d]thiazoline. The corresponding naphth[1,2-d]imidazo[3,2-b]thiazoles were obtained by dehydration of the latter. The structure of the four-ring compounds was proved by reductive desulfurizatton to 3-alkylnaphth[1,2-d]imidazoles and alternative synthesis from 2-chloro-3-acylnaethylnaphth[1,2-d]imidazoles.