A CONVENIENT SYNTHESIS OF 3-ALKYL-2,3-DIHYDRO-2,4-DIOXO-6-PHENYL-4H-1,3-THIAZINES, 3-ALKYL-2,3-DIHYDRO-4-OXO-6-PHENYL-2-THIOXO-4H-1,3-THIAZINES, AND 3-ALKYL-2-ARYLIMINO-2,3-DIHYDRO-4-OXO-6-PHENYL-4H-1,3-THIAZINES

Abstract

The reactions of 1-alkylamino-1-alkylthio-3-phenylpropene-3-thiones 3 with thiophosgene and phosgene in toluene, followed by treatment of the reaction mixture with triethylamine gave 3-alkyl-2,3-dihydro-4-oxo-6-phenyl-2-thioxo- 4, 3-alkyl-2,3-dihydro-2,4-dioxo-6-phenyl-4H-1,3-thiazines 5, respectively in good to excellent yields. Similarly treatment of compounds 3 with N-arylimidoyl dichloride in benzene at room temperature gave 3-alkyl-2-arylimino-2,3-dihydro-4-oxo-6-phenyl-4H-1,3-thiazines 6 in excellent yields. The reactions of compounds 3 with oxalyl chloride in toluene gave also 5 in good yields.