Potassium Hydroxide → 2,3-Dibromo-benzo[b]thiophen-6-ol

Participants

Reaction Steps

Dissolve 2,2-dimethyl-propionic acid 2,3-dibromo-benzo[b]thiophen-6-yl ester (32 g, 82 mmol) in ethanol (725 mL), add 50% aqueous solution of potassium hydroxide (39 mL, 328 mmol) and heat to reflux for 4 hours. Concentrate in vacuo to ½ volume, partition between ethyl acetate (500 mL) and saturated aqueous ammonium chloride (500 mL), separate layers, wash organic with saturated aqueous ammonium chloride (2×500 mL), and brine (300 mL). Dry with sodium sulfate, filter, and concentrate in vacuo to give 25.5 g of 2,3-dibromo-benzo[b]thiophen-6-ol (100%).

Provenance & Evidence