氯化氢催化酯化反应合成2-氯异烟酸甲酯

Synthesis of Methyl 2-Chloroisonicotinate via Esterification Reaction Catalyzed by Hydrogen Chloride

以2-氯异烟酸为起始原料,在氯化氢催化下和甲醇经酯化反应合成纯度98.5%以上的医药中间体2-氯异烟酸甲酯,收率77.7%。目标化合物进行了1 H NMR、IR和GC-MS表征。条件实验表明:当氯化氢浓度为26%,反应温度为40℃,反应时间为3h时,反应效果最佳。探讨了2-甲氧基异烟酸甲酯副产物产生的原因,并对副产物产生的机理进行了推测。

Methyl 2-chloroisonicotinate with purity higher than 98.5% was synthesized via esterification reaction using 2-chloro-isonicotinic acid as starting material and hydrogen chloride as catalyst. The target compound was characterized by 1H NMR.IR and GC-MS. The experimental results showed that the opti- mal reaction conditions were： the concentration of hydrogen chloride was 26%, the reaction temperature was 40 ℃ and the reaction time was 3 h. The reason for the generation of the by-product methyl 2-methox- yl isonicotinate was investigated, and the reaction mechanism was speculated.