4-Chlorophenol → 4-[5-(4-Chloro-phenoxy)-2-trifluoromethoxyphenyl]-2,2,6,6-tetramethylpyran-3,5-dione

Participants

Reaction Conditions

Reaction Steps

To a mixture of 4-(5-bromo-2-trifluoromethoxyphenyl)-2,2,6,6-tetramethylpyran-3,5-dione (0.254 g, 0.62 mmol), 4-chlorophenol (0.400 g, 3.11 mmol), cesium carbonate (0.440 g, 1.25 mmol), copper (II) trifluoromethanesulfonate (11 mg, 0.03 mmol) and powdered 4 Å molecular sieves (0.40 g) is added anhydrous toluene (3.5 ml). After flushing with nitrogen the mixture is heated at 160° C. for 1 hour under microwave irradiation, then cooled to room temperature and quenched with 2M aqueous hydrochloric acid. The crude product is extracted with dichloromethane (×3), and the organic fractions are combined, washed with brine, dried over magnesium sulfate and concentrated in vacuo. Purification by preparative reverse phase HPLC affords 4-[5-(4-chlorophenoxy)-2-trifluoromethoxyphenyl]-2,2,6,6-tetramethylpyran-3,5-dione as a white powder.

Provenance & Evidence