2-甲硫基-7(5)-取代-3-吡唑并[1,5-a]嘧啶甲酸乙酯的区域选择性合成与2D NMR 研究

利用3-甲硫基-4-乙氧羰基-5-氨基-1H-吡唑分别与甲基/芳基烯胺酮反应, 合成了8种新的化合物2-甲硫基-7-取代-3-吡唑并1,5-a]嘧啶甲酸乙酯(3a～3g)和2-甲硫基-5-甲基-3-吡唑并1,5-a]嘧啶甲酸乙酯(4a). 化合物的结构均经元素分析, IR, ¹H NMR, MS所证实, 异构体3a和4a的结构进一步由¹³C NMR, HMQC和HMBC确认. 同时, 探讨了区域选择性合成吡唑并1,5-a]嘧啶类化合物可能的反应机理, 并对部分化合物杀菌活性进行了测试.

Regioselective Synthesis and 2D NMR Research of Ethyl 2-Methyl-thio-7(5)-substituted Pyrazolo[1,5-a]pyrimidine-3-carboxylate

By the reaction of 3-methylthio-4-ethoxycarbonyl-5-amino-1H-pyrazole with substituted enaminones, eight new compounds of ethyl 2-methylthio-7-substituted pyrazolo1,5-a]pyrimidine-3-carboxylate (3a～3g) and ethyl 2-methylthio-5-methyl pyrazolo1,5-a]pyrimidine-3-carboxylate (4a) have been synthesized respectively. The structures of all compounds were characterized by elemental analyses, IR, ¹H NMR, and MS. Structures of regioisomer 3a and 4a were further determined by ¹³C NMR, HMQC and HMBC. In the meantime, the plausible mechanism for regioselective synthesis of pyrazolo1,5-a]pyrimidine was discussed. The preliminary test showed that some of the compounds had somewhat antifungal activities.