作者:Orazio A. Attanasi、Simonetta Buratti、Paolino Filippone、Chiara Fiorucci、Elisabetta Foresti、Daniela Giovagnoli
DOI:10.1016/0040-4020(95)00987-6
日期:1996.1
Thiocarboxylic acids smoothly attack conjugated azoalkenes at room temperature to give hydrazone 1,4-adducts that exhibit tautomerism with the corresponding enamino forms. These adducts when treated with sodium hydride in tetrahydrofuran at room temperature lead to 1-alkoxycarbonyl- or 1-aminocarbonyl-3-methyl-4-acylthio-1H-pyrazol-5(2H)-ones. The same adducts in chloroform with trifluoroacetic acid
硫代羧酸在室温下能平稳地攻击共轭偶氮烯烃,从而生成4- 1,4-加合物,并与相应的烯胺形式互变异构。当在室温下在四氢呋喃中用氢化钠处理这些加合物时,会生成1-烷氧基羰基-或1-氨基羰基-3-甲基-4-酰基硫基-1 H-吡唑-5(2H)-。氯仿中与三氟乙酸在回流下的相同加合物产生1-烷氧基羰基-或1-氨基羰基-3-甲基-4-酰基硫基-5-烷氧基吡唑。在具有四氢呋喃水溶液的酸性介质中,1,4-加合物进行水解,得到2-烯硫基-3-氧代丁酸酯衍生物,其表现出烯醇-酮互变异构现象。1-烷氧基羰基-和1-氨基羰基-3-甲基-4-酰硫基-1 H-吡唑-5(2 H甲醇中的一种衍生物在回流条件下进行溶剂分解,几分钟后得到简单的3-甲基-4-酰基硫基-1 H-吡唑-5(2 H)-酮,数小时后得到4,4 ′-二硫代双(3-甲基-1 H-吡唑-5(2 H)-ones),而1-烷氧羰基-和1-氨基羰基-3-甲基-4