摘要
以3-氨基吡啶为原料,经取代、重氮化得到2,3-二氯吡啶,再与水合肼经亲电取代制得3-氯-2-肼基吡啶。所得产品无需提纯可直接用于下一步反应。所得产物与马来酸二乙酯在氮气保护条件下,以无水乙醇为溶剂,反应得到有机中间体2-(3-氯-2-吡啶基)-5-氧代-3-吡唑烷甲酸乙酯,反应总产率为48.0%。所得产物经IR、1HNMR确定其结构。并对合成工艺进行优化,所得适宜工艺条件(以3-氯-2-肼基吡啶228.57 mmol计):在无水无氧反应体系中,回流状态下滴加马来酸二乙酯速度为10 s/滴时,回流反应1 h,产率为80.1%。
2,3-Dichloropyridine was synthesized from 3-aminopyridine by substitution and diazotization, and then reacted with hydrazine to give 3-chloro-2-hydrazinopyridine by electrophilic substitution. The resultant can be used in the subsequent reaction without purification. Under the protection of nitrogen, with absolute ethanol as solvent, ethyl 3-chloro-2-hydrazinopyridine reacted with diethyl maleate to give 2-（3-chloro-2-pyridinyl）-5-oxo-3-pyrazolidinecarboxylate, the total yield of which was 48.0%. The structure of the products was confirmed by means of IR and 1HNMR. The synthesis process was optimized, and the optimum reaction conditions were ascertained as follows [ based on 228.57 mmo] of 3-chloro-2-hydrazinopyridine] ：in the reaction system with no water or oxygen, the speed of dropping diethyl maleate was 10 s/drop,the reflux was I h.and the vield was 80. 1%.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2011年第9期933-936,共4页
Fine Chemicals
基金
安徽省自然科学基金项目资助(11040606M35)~~
