3-醛基吲哚-4-甲酸乙酯的合成

以2-甲基-3-硝基苯甲酸为起始原料，酸催化酯化得2-甲基-3-硝基苯甲酸乙酯(1)，1与N，N-二甲基甲酰胺二乙基缩醛缩合得β-哌啶基-2-乙氧羰基-6-硝基苯乙烯(2)，然后还原环化得吲哚-4-甲酸乙酯(3)，3再经Vilsmeier-Hacck反应制得标题化合物，反应总收率达57％。产物的结构经IR和^1HNMR得到了确证，纯度为99．2％。

Synthesis of ethyl 3-formylindole-4-carboxylate

The synthetic method for a new compound ethyl 3-formylindole-4-carboxylate has been reported.The intermediate ethyl indole-4-carboxylate(3) was obtained from 2-methyl-3-nitrobenzoic acid(1) as raw material by esterification under the catalyst of acid,it was then condensed with N,N-dimethylformamide diethyl acetal,reduced with iron and acetic acid.3 was then reacted with phosphorus oxychloride and N,N-dimethylformamide through Vilsmeier-Hacck reaction,the target product of ethyl 3-formylindole-4-carboxylate was obtained.The total yield reached 57%.The structure of target product was confirmed by IR and (()~1HNMR) and purity was 99.2%.