Indole → Methyl 1-methyl-1H-indole-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a three-necked round bottom flask was charged 3-indolecarboxylic acid (2.5 g, 15.51 mmol), potassium carbonate (powder, 1.25 g), N,N-dimethylformamide (20 mL) and dimethyl carbonate (3.9 mL, 46.3 mmol). As the stirred mixture was heated to reflux (130° C.), the disappearance of starting indole was monitored by HPLC. After 5 h the reaction was complete, then the mixture was cooled to room temperature and was partitioned between water (50 mL) and tert-butyl methyl ether (100 mL). The separated organic layer was washed with water (2×50 mL) and the volatiles were evaporated under reduced pressure. Purification of the obtained crude by using column chromatography over silica gel furnished 1-methylindole-3-carboxylic acid methyl ester (50% yield) and the decarboxylated byproduct 1-methylindole (45% yield).

Provenance & Evidence