6-Methoxy-1-benzothiophene → Benzo(b)thiophene-6-ol

Participants

Reaction Conditions

Reaction Steps

Dissolve 6-methoxy-benzo[b]thiophene (J. Med. Chem. 32:2548, 1989; 26.1 g, 146 mmol) in DMF (500 mL). Add ethanethiol sodium salt (37 g, 440 mmol) and heats to 150° C. with stirring overnight. Add additional ethanethiol sodium salt (112.8 g, 152 mmol) and continue to heat at 150° C. overnight. Concentrate in vacuo to ¼ volume. Partition reaction mixture between ethyl acetate (500 mL) and water (500 mf), separate layers, wash organic layer with water (2×500 mL), brine (500 mL), and dry with magnesium sulfate. Filter and concentrate in vacuo to give 8 g of benzo[b]thiophen-6-ol. Back extract aqueous layers with ethyl acetate (3×1000 mL) wash organics with brine, and dry with magnesium sulfate. Concentrate in vacuo to obtain an additional 15 grams of benzo[b]thiophen-6-ol. Distill off remaining DMF to yield 22.7 g (100%) of benzo[b]thiophen-6-ol.

Provenance & Evidence