Cesium carbonate → 4-[4-(4-Chloro-3-fluorophenoxy)-2-ethylphenyl]-2,2,6,6-tetramethylpyran-3,5-dione

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Reaction Conditions

Reaction Steps

A mixture of 4-(4-bromo-2-ethylphenyl)-2,2,6,6-tetramethylpyran-3,5-dione (0.20 g, 0.57 mmol), 4-chloro-3-fluorophenol (0.41 g, 2.83 mmol), cesium carbonate (0.40 g, 1.13 mmol), copper(II) trifluoromethanesulfonate (0.01 g, 0.03 mmol) and powdered molecular sieve, 4 Å (0.40 g) in dry toluene (3.5 ml) is heated to 160° C. under microwave irradiation for 1 hour. The mixture is cooled to room temperature diluted with dichloromethane and 2M aqueous hydrochloric acid (10 ml) and passed through a phase separation cartridge. The organic phase is dried over anhydrous magnesium sulfate, filtered and the filtrate is evaporated under reduced pressure. The residue is dissolved in N,N-dimethylformamide (1 ml) and purified by preparative reverse phase HPLC to give 4-[4-(4-chloro-3-fluorophenoxy)-2-ethylphenyl]-2,2,6,6-tetramethylpyran-3,5-dione.

Provenance & Evidence