magnified imageCondensation of thiourea derivatives with 1,4‐dibromobutane gave 1,3‐thiazepine derivatives (1a, 1b, 1c − 3a, 3b, 3c). Elementary analysis, MS and 1H NMR spectra confirmed the identity of the products. The molecular structure of 2b was determined by an X‐ray analysis. J. Heterocyclic Chem., (2009).