Potassium Carbonate → 3-(2-Chloro-4-trifluoromethylphenyl)-4-(4-hydroxybenzyl)-7-methoxychromen-2-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-(chloro-4-trifluoromethylphenyl)-acetic acid (3.2 g, 13.41 mmol) and 1,1′-carbonyldiimidazole (2.72 g, 16.77 mmol) in DMF (15 mL) was heated to 70° C. for 25 min. The reaction mixture was cooled to 10° C. and K2CO3 (2.78 g, 20.1 mmol), 1-(2-hydroxy-4-methoxyphenyl)-2-(4-hydroxyphenyl)-ethan-1-one (1.73 g, 6.7 mmol, prepared as described in Example 4A), DMAP (164 mg, 1.34 mmol) and DMF (10 mL) were added. After stirring the reaction mixture at 115° C. for 1.5 h, the resulting suspension was cooled to r.t., poured onto AcOEt/H2O and the layers were separated. The organic layer was washed with H2O, aq 1N HCl and brine, was dried (MgSO4) and the solvent was removed in vacuo. The resultant red residue was purified using flash chromatography (silica gel, 2:1 to 1:2 hexanes:Et2O) to provide the title compound as a white solid showing: 1H NMR (300 MHz, CDCl3) δ 7.75 (s, 1H), 7.53 (br d, 1H, J=8.0 Hz), 7.47 (d, 1H, J=9.0 Hz), 7.33 (d, 1H, J=8.0 Hz), 6.92-6.85 (m, 3H), 6.80 (d, 1H, J=2.5, 9.0 Hz), 6.70 (d, 2H), J=8.5 Hz), 4.95-4.64 (very br s, 1H), 4.02 (d, 1H, J=15.5 Hz), 3.88 (s, 3H), 3.76 (d, 1H, J=15.5 Hz). MS (ESI) m/z 461 (M+H)+.

Provenance & Evidence