Sodium Carbonate → Benzaldehyde,2-benzo[b]thien-5-yl-

Participants

Reaction Conditions

Reaction Steps

To a suspension of 5-Bromo-benzo[b]thiophene (compound PRE13) (3.68 g, 17.2 mmol) in toluene (183 mL) was added, under nitrogen, tetrakis(triphenylphosphine)-palladium (1.99 g, 1.72 mmol), then a solution of 2-formylphenylboronic acid (3.87 g, 25.8 mmol) in ethanol (20 mL) and at least dropwise aqueous sodium carbonate solution (3.64 g, 34.4 mmol) in water (20 mL). The reaction mixture was then heated to 80° C. for 3 h, cooled, concentrated, partitioned between ethyl acetate (120 mL) and water (70 mL) and acidified with hydrochloric acid (pH˜2). The organic layer was separated, dried over Na2SO4 and concentrated to give a crude residue that was purified by flash chromatography (silica, eluting solvent: (petroleum ether/AcOEt) 9.2/0.8) to give 3.31 g of compound PRE14 (orange yellow powder; yield=81%).

Provenance & Evidence