Potassium Carbonate → 3-(3,3-Dimethyl-5-propionyl-2,3-dihydro-benzofuran-7-yl)-4-trifluoromethoxy-benzaldehyde

Participants

Reaction Steps

A mixture of 1-[3,3-dimethyl-7-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-2,3-dihydro-benzofuran-5-yl]-propan-1-one (1.33 g, 4.05 mmol), 3-bromo-4-trifluoromethoxybenzaldehyde (example 1h) (1.09 g, 4.05 mmol) and potassium carbonate (1.12 g, 8.10 mmol) in toluene (12 mL), ethanol (2.4 mL) and water (1.5 mL) was degassed with argon for 30 minutes. Tetrakis(triphenylphosphine)palladium(0) (234 mg, 0.20 mmol) was added and the mixture heated at reflux under argon for 19 hrs. The solution was cooled to room temperature, diluted with ethyl acetate and washed successively with water and brine, dried over anhydrous magnesium sulfate, filtered and evaporated. The residue was purified on silica gel (10% ethyl acetate in hexane) to give 1.17 g of 3-(3,3-dimethyl-5-propionyl-2,3-dihydro-benzofuran-7-yl)-4-trifluoromethoxy-benzaldehyde (50%). 1H NMR (300 MHz; CDCl3): 1.23 (t, J=7.2 Hz, 3H), 1.42 (s, 6H), 2.99 (q, J=7.2 Hz, 2H), 4.34 (s, 2H), 7.52 (dd, J1=7.2 Hz, J2=1.8 Hz, 1H), 7.84 (d, J=2.1 Hz, 1H), 7.85 (d, J=2.13 Hz, 1H), 7.96 (dd, J1=8.4 Hz, J2=2.1 Hz, 1H), 8.03 (d, J=2.1 Hz, 1H), 10.05 (s, 1H).

Provenance & Evidence