Fused polycyclic nitrogen-containing heterocycles 13. Synthesis of 6-phenyl-2-phenylimino-6H-1,3,4-thiadiazine-5-carboxylic acid and its intermolecular cyclodehydration accompanied by sulfur extrusion to form dipyrazolo[1,5-a,1′,5′d]pyrazine
作者:V. A. Mamedov、I. Z. Nurkhametova、A. T. Gubaidullin、I. A. Litvinov、Ya. A. Levin
DOI:10.1007/s11172-005-0270-z
日期:2005.2
Condensation of methyl phenylchloropyruvate with 4-phenylthiosemicarbazide proceeds as the Bose reaction to form 5-methoxycarbonyl-6-phenyl-2-phenylimino-6H-1,3,4-thiadiazine, which is hydrolyzed to give carboxylic acid. In the presence of polyphosphoric acid, the latter undergoes intermolecular cyclodehydration accompanied by sulfur extrusion to yield dipyrazolo [1,5-a,1′,5′d]pyrazine.
苯基氯丙酮酸甲酯与 4-苯基氨基硫脲在 Bose 反应中缩合,形成 5-甲氧羰基-6-苯基-2-苯基亚氨基-6H-1,3,4-噻二嗪,水解生成羧酸。在多磷酸存在下,多磷酸发生分子间环化脱水并伴随硫挤出生成二吡唑并[1,5-a,1',5'd]吡嗪。