溴保护法合成4-甲氧基-2-吲哚酮工艺研究

STUDY ON THE SYNTHESIS OF 4-METHOXY-2-INDOLINONE BY BROMO-PROTECTION APPROACH

将溴保护法应用到4-甲氧基-2-吲哚酮合成中,以间甲氧基苯胺为原料,经一锅法溴化、Sandmeyer异亚硝基乙酰替苯胺合成法制备得5,7-二溴-4-甲氧基靛红后,再经钯碳加氢脱溴、水合肼一锅法还原反应制备得目标产物,总收率达54.14%。考察了溴化反应溴素用量、Sandmeyer反应过程反应温度和反应时间对收率的影响,所有产物结构均通过~1H NMR、^(13) C NMR、元素分析等进行了表征。结果表明,溴化反应中甲氧基苯胺与溴素的较佳摩尔比为1∶2.2,Sandmeyer反应适宜的反应条件为80℃反应2h。

The bromine protection method was applied to the synthesis of 4-methoxy-2-indolinone with m-methoxyaniline as raw material.5,7-Dibromo-4-methoxyisatin was prepared by one-pot Bromination and Sandmeyer Isonitrosoacetanilide Isatin Synthesis,followed by palladium carbon hydrogenation of bromine and hydrazine hydrate one-pot reduction to give 4-methoxy-2-indolinone with the total yield of 54.14%.The effects of dosage of bromine,Sandmeyer reaction＇s temperature and time on the yield were investigated.All products＇ structures were characterized by ^1 H NMR,^13 CNMR and elemental analysis.The result shows that the optimized molar ratio of m-methoxyaniline to bromine was 1∶2.2 in the bromination reaction and the optimum Sandmeyer reaction condition is 80℃for 2 h.