Studies on the chemistry of O,N‐ and S,N‐containing heterocycles. 12 [1]. Investigations on the synthesis of tricyclic 1,5‐benzoxazepines

The reaction of methylthiolactim 1 with weak basic N‐nucleophiles led to the substituted benzoxazepines 2,3 and 6a‐d, respectively. Compound 4 was obtained by condensation of 3 with carbonyldiimidazole, whereas 6a‐d were transformed thermically into the triazolobenzoxazepines 7a‐d. Treatment of 6b with thionyl chloride afforded 8. Compound 9 directly was obtained from 1 with anthranilic acid.