Selenium heterocycles. XXXII . Synthesis of [1]benzoxepino[3,4‐d]‐thiazole, [1]benzothiepino[3,4‐d]thiazole, [1]benzoxepino[3,4‐d]selenazole, and [1]benzothiepino[3,4‐d]selenazole. four novel heterocycles

Abstract Starting from the readily available ethyl 2‐phenyl‐4‐methyl‐thiazole‐5‐carboxylate (III), 2‐phenyl‐4‐chloromethyl‐thiazole (VIII) and 2‐aryl‐4‐chloromethylselenazole (XIV), 2‐phenyl‐4,10‐dihydro‐10‐oxo‐[1]benzoxepino[3,4‐d]thiazole (Ia), 2‐phenyl‐4,10‐dihydro‐10‐oxo[1]benzothiepino[3,4‐d]thiazole (Ib), 2‐aryl‐4,10‐dihydro‐10‐oxo[1]benzoxepino[3,4‐d]selenazoles (IIa‐IIe) and 2‐aryl‐4,10‐dihydro‐10‐oxo[1]benzothiepino[3,4‐d]selenazoles (IIf‐IIj) were prepared.