Conversion of N-arylimino-4-chloro-5H-1, 2, 3-dithiazole 11 into the 4-alkoxyquinazoline-2- carbonitriles 13a-i and of the aryl isothiocyanates 15 into aryl thiocarbamates 16a-j with sodium alkoxides in the corresponding alcohol, either by conventional thermolysis or by microwave irradiation are described and directly compared. Microwave irradiation of the solutions in open vessels in a monomode system with focused irradiation and continuous ...