Zur Umsetzung des 3,4,5,6-Tetrahydro-6-hydroxy-4,4,6-trimethyl-1,3-thiazin-2-thions mit primären Aminen

Tetrahydro-6-hydroxy-4,4,6-trimethyl-1,3-thiazine-2-thione (1 a) reacts with methyl-, ethyl- and n-butylamine to the corresponding 1-alkyl-6-alkylaminotetrahydro-2(1H)-pyrimidinethione12 but withi-propylamine to tetrahydro-6-isopropylamino-1,3-thiazine-2-thione (6 d). On treatment withDCC,6 d is rearranged to dihydro-4-isopropylamino-2(1H)-pyridinethione (8 d), and 6-amino-tetrahydro-1,3-thiazinethione (6 a) to dihydro-4,4,6-trimethyl-2(1H)-pyrimidinethione (10 a). The reaction of 6-aminothiazinethiones6 a, d and 6-(4-morpholinyl)-thiazinethione13 resp., with methylamine leads to 1-methyl-6-methylamino-pyridinethione12 b. 1-Alkyl-6-alkylamino-tetrahydro-2(1H)-pyrimidinethiones (12) react at reflux temperature to dihydro-1-alkylpyrimidinethiones10. With methylamine only 6-methylamino-3,4,4,6-tetramethyl-1,3-thiazine-2-thione (6 f) is formed from tetrahydro-6-hydroxy-tetramethyl-1,3-thiazine-2-thione (1 b).