AbstractTwo routes are described for the synthesis of 1,3‐benzo[e]thiazepines, a novel class of heterocyclic compounds. The first route is a reaction between 2‐bromo‐methylbenzyl or 2‐bromomethylbenzoyl bromide and a thioamide or a thiourea. In an analogous reaction a 1,3‐thiazepine can be synthesized from 4‐bromobutyryl chloride andN,N′‐diphenylthiourea. The second route comprises cyclization ofN′‐(2‐bromomethylbenzoyl)‐N′‐disubstituted thioureas. Rather unexpectedly, the correspondingN′‐monosubstituted compounds yielded benzo[c]pyrrolidine derivatives. Pyrrolidines were observed from the cyclization ofN′‐(4‐bromobutyryl)‐N′‐mono/disubstituted thioureas.The reaction mechanisms and the spectroscopic data of the reaction products are discussed.The 1,3‐benzo[e]thiazepines were converted into the correspond