Sulfuric Acid → methyl 1H-indole-5-carboxylate

Participants

Reaction Steps

A methanol (200 ml) solution of indole-5-carboxylic acid (5.15 g) was refluxed in the presence of concentrated sulfuric acid (3 ml) at 85° C. for 4.5 hours. After the reaction, saturated aqueous sodium hydrogencarbonate solution was added at 0° C. and the mixture was extracted with ethyl acetate. The organic phase was washed with brine and dried over magnesium sulfate, then the solvent was evaporated in vacuo and the residue was purified by silica gel column chromatography to obtain indole-5-carboxylic acid methyl ester (4.8 g).

Provenance & Evidence