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[方法]以氰乙酸乙酯和原甲酸三乙酯为原料,通过Claisen酯缩合、合环、脱氨基和水解等一系列反应合成1H-吡唑-4-甲酸,探讨了各步反应的影响因素。[结果]氰乙酸乙酯和原甲酸三乙酯的投料摩尔比1∶1.2,室温下反应16 h合环,在冰水浴中用盐酸和亚硝酸钠脱氨,10%氢氧化钠溶液水解,总收率97.1%,产物的结构经MS、1H NMR和13C NMR确证。[结论]该合成路线具有成本低、操作简单、适于工业化生产的优点。
[Method] With ethyl cyanoacetate and triethyl orthoformate as raw materials, 1H-pyrazole-4-carboxylic acid was synthesized through a series of reactions such as Claisen ester condensation, cyclization, deamination and hydrolysis, and the influence of each step reaction factor. [Result] The molar ratio of ethyl cyanoacetate and triethyl orthoformate was 1: 1.2. The reaction was carried out at room temperature for 16 hours. The reaction was quenched with hydrochloric acid and sodium nitrite in an ice-water bath and hydrolyzed with 10% sodium hydroxide solution. The total yield of 97.1%, the structure of the product by MS, 1H NMR and 13C NMR confirmed. [Conclusion] The synthetic route has the advantages of low cost, simple operation and suitable for industrial production.