Abstract Imidazo [2, 1-b][1, 3, 5] benzothiadiazepine 3 constitutes a novel ring system, and its analogs 3a-i were synthesized to investigate their potential antipsychotic activity. The synthesis of the ring system was achieved by reaction of 2-aminophenylthioimidazoles 7 with phosgene or thiophosgene and by ring closure of the 1-[2-(2-imidazolyl) thiophenyliminocarbonyl]-1-piperazines 13. An efficient method for the conversion of ...