Ring Transformation of 1,1-Dioxo-1,2-thiazine-6-carbaldehydes with Nitrogen Nucleophiles to Substituted Pyridine-3-sulfonanilides
作者:E. Fanghänel、A. Hucke、Th. Lochter、U. Baumeister、H. Hartung
DOI:10.1055/s-1996-4382
日期:1996.11
1,1-Dioxo-1,2-thiazine-6-carbaldehydes 1 possessing a masked 1,5-dicarbonyl structure react with hydroxylamine with ring transformation to form the pyridine N-oxides 2. These can be deoxygenated with PCl3 to give the corresponding pyridine-3-sulfonanilides 3, which are available by the reaction of 1 with ammonia as well. The ring transformation of 1 with methylamine, benzylamine and hydrazine produces N-substituted mesoionic pyridinium salts 6-8. The cyclohexane-fused thiazine-6-carbaldehyde 9 can be transformed with ammonia to the 5,6,7,8-tetrahydroquinoline 10. Reaction of 2 with NaNO2/HCl enables the introduction of the nitro group into the anilide part of the molecule.
1,1-二氧代-1,2-噻嗪-6-甲醛1具有掩蔽的1,5-二羰基结构,与羟胺发生环转化反应,形成吡啶N-氧化物2。这些化合物可用PCl3脱氧,得到相应的吡啶-3-磺酰苯胺3,也可通过1与氨反应得到。1与甲胺、苄胺和肼发生环转化反应,生成N-取代的介离子吡啶鎓盐6-8。环己烷稠合噻嗪-6-甲醛9可与氨发生反应,生成5,6,7,8-四氢喹啉10。2与NaNO2/HCl反应,可将硝基引入分子的苯胺部分。