3/4-phenylene bisheterocycles from ring transformation reaction of sydnone derivatives: Synthesis of 3-[3/4-heterocyclyl]phenyl-5-methyl-3H-[1,3,4]-oxadiazol-2-ones from 3/4-acetylphenylsydnones and their biological properties
作者:Ravindra R. Kamble、Prashant R. Latthe、Bharati V. Badami
DOI:10.1002/hc.20255
日期:——
bifunctional 3/4-[acetyl]phenylsydnones 1a, 1b were subjected to a one-pot ring conversion to 3-[3/4-acetyl]phenyl-5-methyl-3H-[1,3,4]-oxadiazol-2-ones 2a, 2b, which on further bromination yielded the 3-[3/4-bromoacyl]phenyl-5-methyl-3H-[1,3,4]-oxadiazol-2-ones 3a, 3b. Reaction of these compounds with thiourea yielded the 3-[3/4-(2-aminothiazol-4-yl)]phenyl-5-methyl-3H-[1,3,4]-oxadiazol-2-ones 4a, 4b. The other
双官能的 3/4-[乙酰]苯基sydnones 1a、1b 进行一锅环转化为 3-[3/4-乙酰]苯基-5-甲基-3H-[1,3,4]-恶二唑- 2-ones 2a, 2b,进一步溴化产生 3-[3/4-bromoacyl]phenyl-5-methyl-3H-[1,3,4]-oxadiazol-2-ones 3a, 3b。这些化合物与硫脲反应产生 3-[3/4-(2-氨基噻唑-4-基)]苯基-5-甲基-3H-[1,3,4]-恶二唑-2-酮 4a、4b。其他噻唑衍生物 5a、5b-7a、7b 分别使用氨基硫脲、硫代乙酰胺和硫代苯甲酰胺制备。在溴乙酰化合物 (3a, 3b) 与 2-氨基吡啶和 2-氨基噻唑的另一个反应中,稠合双杂环化合物 3-[3/4-imidazo-[1,2-a]pyridine-2-yl]phenyl-5 -methyl-3H-[1,3,4]-oxadiazol-2-ones