Indole → methyl 2-(1H-indol-1-yl)acetate

Participants

Reaction Steps

NaH (0.6 g, 15.0 mmol.) was added, while cooling with ice, to a solution of indole (1.17 g, 10.0 mmol.) and bromoacetic acid methyl ester (1.43 ml, 15 mmol.) in DMF. (20 ml), and stirring was carried out for 24 h at RT. For working up, water (50 ml) was added to the mixture, and extraction was carried out with EE (5×20 ml). The combined extracts were dried, filtered and concentrated. Chromatography with EE/cyclohexane (1:7) yielded 1.17 g of indol-1-yl-acetic acid methyl ester in the form of a colourless oil. These 1.17 g (6.18 mmol.) were dissolved in abs. methanol (100 ml); KOH (382 mg, 6.8 mmol.) was added and the mixture was heated at reflux for 2 h. For working up, the mixture was concentrated, water (20 ml) was added to the residue, the pH was adjusted to 4 with 1M HCl and the resulting solid was filtered off with suction. Indol-1-ylacetic acid was obtained in a yield of 0.96 g (white solid, m.p. 128–130° C.).

Provenance & Evidence