Sodium Hydroxide → 5-Bromo-6-methoxybenzo[b]thiophene-3-carboxylic acid

Participants

Reaction Steps

Ethyl 5-bromo-6-methoxybenzo[b]thiophene-3-carboxylate (D4) (0.42 g, 0.0013 mole) in ethanol (20 ml) and water (5 ml) was treated with sodium hydroxide powder (0.14 g, 0.0035 mole). The reaction mixture was heated under reflux for 2 hours and stirred at ambient temperature for 16 hours. The solvent was removed in vacuo and the residue diluted with water (25 ml), acidified with 5N hydrochloric acid, extracted into ethyl acetate, dried (Na2SO4) and evaporated in vacuo to afford the title compound (0.36 g, 93%) as a beige solid.

Provenance & Evidence