Sodium borohydride → Imidazo[1,2-a]pyridine-7-methanol

Participants

Reaction Steps

To a cooled (0° C.) solution of imidazo[1,2-α]pyridine-7-carboxylic acid methyl ester (2.15 g, 12.2 mmol) in methanol (50 ml) was added sodium borohydride (4.64 g, 12.2 mmol) in portions over 15 min. The mixture was heated under reflux for 3 h, cooled to ambient temperature and evaporated to dryness. The residue was dissolved in dichloromethane:methanol (300 ml of a 1:1 mixture) and pre-adsorbed onto silica. Purification by silica gel chromatography eluting with dichloromethane/methanol/conc. ammonia (95:5:0.5) gave imidazo[1,2-α]pyridin-7-ylmethanol (1.75 g, 77%) as a colourless oil. 1H NMR (400 MHz, CDCl3) δH 4.71 (2H, s), 6.79 (1H, dd, J 7 and 1), 7.37 (1H, s), 7.52 (1H, s), 7.56 (1H, d, J 1), 8.05 (1H, d, J 7).

Provenance & Evidence