3-氨基-2-吡咯甲酸乙酯盐酸盐的合成工艺改进

Synthesis of ethyl 3-amino-1H-pyrrole-2-carboxylate hydrochloride

改进了3-氨基-2-吡咯甲酸乙酯盐酸盐的合成工艺,经过4步反应合成了目标化合物,包括在氢化钠催化下甲酸乙酯和乙腈缩合后再与氨基丙二酸二乙酯缩合,然后经乙醇钠关环及与氯化氢成盐得到;应用氢核磁共振及元素分析对样品结构进行了表征;对各步反应的条件进行改进,结果表明:原料的最优比例是n(HCOOC2H5)∶n(CH3CN)∶n(NaH)∶n[NH2CH(COOC2H5)2HCl]=1∶1.2∶1.3∶0.5,反应温度为20℃,反应时间分别为24h和48h;在工艺改进的情况下,反应收率得到较大提高,生产成本降低,适合工业化生产。

A process suitable for large-scale preparation of 3-amino-lH-pyrrole-2-carboxylate hydrochloride was developed. The title compound was synthesized through four steps, which include the condensation of ethyl formate with acetonitrile by using Nail as the promoter, condensation with diethyl 2-aminomalonate hydrochloride, cyclization in the presence of NaOEt, and reaction with hydrogen chloride. The characteristics of the title compound was investigated with 1HNMR and elemental analysis The results showed that the optimum molar ratio of n（HCOOC2H5） ： n（CH3CN） ： n（NaH） ： n（NH2CH（COOC2H5）2HCl） was 1 ： 1.2 ; 1.3 ： 0.5, the reaction temperature was 20 ℃ and the reaction time was 24 and 48 hours respectively. The procedure was a suitable alternative to the traditional processes due to safety, stability, and handling concerns.