Ethanol → 1H-Benzimidazole-2-acetic acid

Participants

Reaction Steps

A mixture of 2-benzimidazolylacetonitrile (5.58 g, 35.5 mmol) and 4M sodium hydroxide solution (25 ml) in ethanol (100 ml) was heated at reflux for 8 h. The reaction mixture was concentrated in vacuo, the residue dissolved in water (100 ml), and extracted with ethyl acetate (2×100 ml). The aqueous phase was acidified with dilute hydrochloric acid to pH 4-5, the precipitated solid was filtered, washed with water, and dried to give the title compound (5.97 g, 95%) as a buff solid; δH (DMSO-d6) 2.47 (2H, s, CH2CO2H), 7.09 (2H, m, ArH), 7.39 (1H, brs, ArH), 7.48 (1H, brs, ArH), and 12.13 (1H, brs, NH).

Provenance & Evidence