Hydrochloric Acid → 4-(3',4'-Difluoro-4-methylbiphenyl-3-yl)-2,2,6,6-tetramethylpyran-3,5-dione

Participants

Reaction Conditions

Reaction Steps

To a microwave vial is added 4-(5-chloro-2-methylphenyl)-2,2,6,6-tetramethyl-pyran-3,5-dione (0.20 g, 0.68 mmol), 3,4-difluoro-phenylboronic acid (0.107 g, 0.68 mmol), potassium phosphate (0.722 g, 3.40 mmol), palladium(II) acetate (1.6 mg, 0.0068 mmol) and sodium S-phos-3′-sulphonate (7.0 mg, 0.0136 mmol). Distilled, degassed water (0.75 ml) is next added (washing-down any solids from the slides of the vial), followed by stirring for 5 minutes and flushing with argon. This mixture is then heated at 160° C. under microwave irradiation for 15 minutes, followed by the addition of extra 3,4-difluorophenylboronic acid (0.107 g, 0.68 mmol) and potassium phosphate (0.144 g, 0.68 mmol), then further heating at 160° C. under microwave irradiation for 15 minutes. After cooling to room temperature the reaction mixture is diluted with ethyl acetate (3 ml) and acidified to pH2 with dilute aqueous hydrochloric acid. The organic phase is separated and the aqueous phase is further extracted with ethyl acetate (3×3 ml). All organics are then combined, filtered through a silica plug and evaporated to give a crude product which is dissolved in N,N-dimethylformamide (2.5 ml) and purified by preparative reverse phase HPLC to afford 4-(3′,4′-difluoro-4-methylbiphenyl-3-yl)-2,2,6,6-tetramethylpyran-3,5-dione (0.190 g) as a white solid.

Provenance & Evidence