Triethylamine → 2-Cyclopropanecarbonyl-7-methoxybenzofuran-4-carboxylic Acid

Participants

Reaction Steps

To a solution of (4-bromo-7-methoxybenzofuran-2-yl)-cyclopropyl-methanone (1.0 g) in tetrahydrofuran/water (40 ml/20 ml) was added palladium acetate (76 mg), 1,3-bis(diphenylphosphino)propane (280 mg) and triethylamine (4.7 ml). The reaction mixture was heated at 90° C. under a 150 psi atmosphere of carbon monoxide for 3 days. The reaction mixture was allowed to cool to room temperature and the carbon monoxide pressure released. The tetrahydrofuran was removed in vacuo and the aqueous residue washed with ethyl acetate (2×75 ml) and acidified to pH3 with 2M hydrochloric acid. The latter was extracted with ethyl acetate (2×200 ml), the organic layer separated, dried over magnesium sulfate, filtered and concentrated in vacuo to afford the title compound as a pale yellow solid (0.76 g).

Provenance & Evidence