Synthesis of heterocycles using a new immonium salt derived from NN-dimethylthiourea

Abstract

The preparation of a new immonium salt (2) by the reaction of NN-dimethylthiourea with carbon disulphide, followed by methylation with an excess of methyl iodide, is reported. The reaction of compound (2) with nucleophiles affords several useful heterocycles such as the mesoionic triazolines (3), the triazolines (4), an oxadiazole (5), a thiazole (6), a triazine (7), a benzoxadiazepine (9), and a benzothiadiazepine (11).