含硫黄ピリジン誘導体について (第52報)

ピリド-1,4-チアジン誘導体の合成 その3

抄録

Stability of the thiazine ring in pyrido-1, 4-thiazine derivatives was examined with 6-methoxy-1H-pyrido[2, 3-b]-1, 4-thiazine derivatives as the sample. The methylene in 3-position of 2-phenylpyrido[2, 3-b]-1, 4-thiazine derivatives is sensitive to oxidation irrespective of the kind of substituent in the 6-position and the compounds were found to be oxidized stepwise to 3, 3′-bis (2-phenyl-3H-pyrido[2, 3-b]-1, 4-thiazinylidene) via the 3, 3′-bis (2-phenyl-1H-pyrido[2, 3-b]-1, 4-thiazinyl).