1H-吡唑-4-甲酸的合成改进

Improved Synthesis of 1H-Pyrazole-4-Carboxylic Acid

以氰乙酸乙酯和原甲酸三乙酯为原料,通过Claisen酯缩合、合环、脱氨和水解得到1H-吡唑-4-甲酸。用质谱(MS)、核磁共振氢谱(1H NMR)和核磁共振碳谱(13C NMR)表征了化合物的结构。实验结果表明,1H-吡唑-4-甲酸的收率由文献报道的70%提高到了97.1%。

1H-pyrazole-4-carboxylic acid was synthesized from ethyl cyanoacetate and triethyl orthoformate via Claisen condensation,cyclization,deamination and hydrolysis reactions.The intermediate compound and the title compound were characterized by MS,1H NMR and 13C NMR.With this method,the yield of 1H-pyrazole-4-carboxylic increased from 70% reported in literature to 97.1%.