摘要
[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。
[Methods] 1H-pyrazole-4-carboxylic was synthesized with ethyl cyanoacetate and triethyl orthoformate as raw matetials via Claisen condensation,cyclization,deamination and hydrolysis.the effect factors of reaction conditions were also discussed.[Results] Ethyl cyanoacetate：triethyl orthoformate（molar ratio） was 1：1.2,cyclization time was 16 h at room temperature and deamination was carried out with hydrochloric acid and sodium nitrite in ice water bath,followed by hydrolysis with 10% NaOH.the yield of target product was 97.1%.The structure of the product was confirmed by MS,1H NMR and 13C NMR.[Conclusions] The method has the advantage of low cost,safe operation and suitable for industrial production.
出处
《农药》
CAS
北大核心
2011年第2期100-101,共2页
Agrochemicals
