Ring formation and ring opening reactions of a dihydrothiadiazine cycle fused to 1,2,4-triazole

A new method of dihydrothiadiazine cycle annelation to 1,2,4-triazole derivatives is suggested and a ring opening reaction of the obtained dihydrothiadiazine cycle is found, leading to a substituted desoxybenzoine; the structures of both reaction products are supported by X-ray analysis.