氧化吲哚的绿色合成工艺研究

以邻硝基甲苯为原料在乙醇钠催化下与草酸二乙酯缩合、水解、双氧水氧化、盐酸酸化得到邻硝基苯乙酸收率为62%。在水溶液中,以FeO(OH)为催化剂,水合肼还原邻硝基苯乙酸得到氧化吲哚。考察了还原过程中影响反应的因素。结果表明,水合肼∶邻硝基苯乙酸=3∶1(摩尔比),催化剂FeO(OH)的用量为0.2 g/mmol邻硝基苯乙酸,溶剂水的用量为5 mL/mmol邻硝基苯乙酸,回流反应1.0 h,氧化吲哚的收率为95%。两步总收率达59%。

Study on green process for synthesis of oxindole

o-Nitrophenylacetic acid was synthesized by condensation of o-nitrotoluene with diethyl oxalate catalyzed by C_2H_5ONa,hydrolysis,oxidation with H_2O_2 and acidation with HCl in about 62% yield.It was further converted to oxindole through reduction by hydrazine hydrate in water,catalyzed by(FeO(OH)).The effect of various factors in the process of reduction was investigated.The results showed that under the conditions of the mole ratio of hydrazine hydrate to o-nitrophenylacetic acid is 3∶1,the quantity of catalyst FeO(OH) is 0.2 g/mmol o-nitrophenylacetic acid,the quantity of water is 5 mL/mmol o-nitrophenylacetic acid and the reaction time for 1.0 h,the yield of oxindole is about 95%.The overall yield is about 59%.