Water → Benzo[b]thiophene-2-propionic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of benzo[b]thiophene-2-propanoic acid ethyl ester (3.52 g, 15.0 mmol) in MeOH (200 mL) was added at 0° C. 10% KOH/MeOH (70 mL, 144 mmol) and H2O (30 mL). The solution was stirred at 25° C. for 6 h then kept in a refrigerator (0° C.) overnight. After addition of H2O (20 mL), the mixture was concentrated under reduced pressure to remove most of MeOH then acidified carefully with 3N HCl to pH 2. The resultant turbid mixture was extracted with Et2O (3×500 mL). The combined extracts were washed with brine (200 mL), dried (MgSO4), and concentrated to dryness to give benzo[b]thiophene-2-propanoic acid (3.04 g, 14.7 mmol) in 98% yield as a solid, mp 140°-142° C.

Provenance & Evidence