Reaction of 3-Acetonyl-5-cyano-1,2,4-thiadiazole with Phenylhydrazine Hydrochlorides: Indolization and Phenylpyrazolation.
作者:Tsuneo IWAKAWA、Hiroshi NAKAI、Giichi SUGIMORI、Akira MURABAYASHI
DOI:10.1248/cpb.48.160
日期:——
provided 5-cyano-3-(2,5-dimethylindol-3-yl)-1,2,4-thiadiazole (2) or 5-cyano-3-(5-methoxy-2-methylindol-3-yl)-1,2,4-thiadiazole (3) as the sole product, respectively. In contrast, treatment of 1 with phenylhydrazine hydrochloride resulted in the formation of 5-cyano-3-(2-methylindol-3-yl)-1,2,4-thiadiazole (4) and the unexpected 5-cyano-3-(3,5-dimethyl-1-phenylpyrazol-4-yl)-1,2,4-thiadiazole (5). In a similar
用4-甲基或4-甲氧基苯基肼盐酸盐处理3-丙酮基-5-氰基-1,2,4-噻二唑(1),得到5-氰基-3-(2,5-二甲基吲哚-3-基)-1,单独的产物分别为2,4-噻二唑(2)或5-氰基-3-(5-甲氧基-2-甲基吲哚-3-基)-1,2,4-噻二唑(3)。相反,用盐酸苯肼处理1会形成5-氰基-3-(2-甲基吲哚-3-基)-1,2,4-噻二唑(4)和意外的5-氰基-3-( 3,5-二甲基-1-苯基吡唑-4-基)-1,2,4-噻二唑(5)。以类似的方式,当用盐酸4-氯苯肼处理1时,通过苯基吡唑化抑制吲哚化,产生5-氰基-3-(5-氯-2-甲基吲哚-3-基)-1,2,4-噻二唑(6)和5-氰基-3- [1-(4-氯苯基)-3,5-二甲基吡唑-4-基] -1,2,4-噻二唑(7)。讨论了反应机理。化合物4