Synthesis of 2,3,5,6-tetrahydro-4H-1,4-thiazin-3-one 1,1-dioxides from methyl (styrylsulfonyl)acetate

Article abstract of DOI:10.1002/jhet.5570330203

Methyl (styrylsulfonyl)acetate (1) was shown to be a useful building block for the synthesis of 5-phenyl-2,3,5,6-4H-tetrahydro-1,4-thiazin-3-one (2), its 4-amino 3, and 4-hydroxy 4 derivatives. Their 2-spirocyclopropanes 9, 10, and 11, and 2,7-diphenyl-6,7-dihydro-8H-pyrimido[5,4-b][1,4]thiazine 5,5-dioxide (18) were also prepared from 1.