Novel xanthine oxidase inhibitor studies. Part 3. Convenient and general syntheses of 3-substituted 7H-pyrazolo[4,3-e]-1,2,4-triazolo[4,3-c]pyrimidin-5(6H)-ones as a new class of potential xanthine oxidase inhibitors
作者:Tomohisa Nagamatsu、Takayuki Fujita、Kazuki Endo
DOI:10.1039/a907673e
日期:——
Convenient and general syntheses of 3-substituted 7H-pyrazolo[4,3-e]-1,2,4-triazolo[4,3-c]pyrimidin-5(6H)-ones (12), a new class of potent xanthine oxidase inhibitors, involving the oxidative cyclisation of 6-substituted 4-alkylidenehydrazino- or 4-arylmethylidenehydrazino-1H-pyrazolo[3,4-d]pyrimidines (3 and 11) with 70% nitric acid as the key step, are reported. The hydrazones 3 and 11 were obtained by a versatile synthetic route via the key intermediates, 6-chloro-4-hydrazino-1H-pyrazolo[3,4-d]pyrimidine 2 or oxypurinol 4, starting from 2,4,6-trichloropyrimidine-5-carbaldehyde 1. Their inhibitory activities against bovine milk xanthine oxidase in vitro are also described; i.e. the pyrazolotriazolopyrimidines 12 were several hundred times more potent than allopurinol.
报道了一种方便且通用的合成方法,用于合成3取代的7H-pyrazolo[4,3-e]-1,2,4-triazolo[4,3-c]pyrimidin-5(6H)-酮(12),这是一类新型的强效黄嘌呤氧化酶抑制剂。该合成涉及到以70%浓硝酸进行的6取代4-烯基氨基或4-芳基甲烯基氨基-1H-pyrazolo[3,4-d]pyrimidines(3和11)的氧化环化作为关键步骤。氢肼衍生物3和11是通过一个多功能合成路线获得的,该路线以关键中间体6-氯-4-氨基-1H-pyrazolo[3,4-d]pyrimidine(2)或氧嘌呤醇(4)为起始物,开始自2,4,6-三氯嘧啶-5-醛(1)。同时也描述了它们对牛乳黄嘌呤氧化酶的体外抑制活性;即,pyrazolotriazolopyrimidines(12)的活性比别嘌呤明显强几百倍。