2-Formylaminodiphenylacetylenes, obtained in excellent yield by Sonogashira coupling of (2-iodoaryl)formamides with phenylacetylene, were thionated with P 4 S 1 0 in boiling THF to give 2-thioformylaminodiphenylacetylenes.These acetylenes were cyclised by DBU at ambient temperature to give (4Z)-4-benzylidene-4H-3,1-benzothiazines and small amounts of 2-phenylindoles. The structures of (4Z)-4-benzylidene-6,8-dichloro-4H-3,1-benzothiazine and 3,5-dichloro-2-thioformylaminodiphenylacetylene were established by single crystal X-ray analysis.

中文翻译：

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2-硫甲氨基二苯乙炔环化合成3,1-苯并噻嗪

通过（2-碘芳基）甲酰胺与苯乙炔的 Sonogashira 偶联以优异的收率获得 2-甲氨基二苯乙炔，在沸腾的 THF 中用 P 4 S 1 0 硫代化，得到 2-硫甲氨基二苯乙炔。这些乙炔在环境温度下通过 DBU 环化得到（ 4Z)-4-苯亚甲基-4H-3,1-苯并噻嗪和少量2-苯基吲哚。(4Z)-4-benzylidene-6,8-dichloro-4H-3,1-benzothiazine 和 3,5-dichloro-2-thioformylaminodiphenylacetylene 的结构是通过单晶 X 射线分析建立的。