Synthese und Reaktionsverhalten von 6-sec-Amino-1,3-thiazin-2-thionen

The title compounds3 have been prepared by ring transformation reactions of the isomeric 2-sec-amino-1,3-thiazine-6-thiones1 via ring-opening products2 and by special cyclocondensation reactions with thiocarboxamides8, and with iminium salts10, starting from 2,2-dichlorovinyl ketones6 in all cases. The pathways differ specifically in scope and limitations. On the other hand the intermediates2 react with alkylating agents to 2,6-di-sec-amino-1,3-thiazinium salts4, which are also available via alkylation of3 to 2-methylthio-1,3-thiazinium salts11 and aminolysis. Moreover,11 serve as useful precursors for other 1,3-thiazine derivatives by nucleophilic methylthio displacement (examples12).