Potassium Phosphate, Tribasic → 2-Chloro-5-[2-(2,4-difluorophenoxy)-5-nitrophenyl]-4-fluoropyridine

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-chloro-4-fluoro-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (170 mg, 0.66 mmol), 2-bromo-1-(2,4-difluorophenoxy)-4-nitrobenzene (326 mg, 0.98 mmol), Pd2(dba)3 (30 mg, 5%), and tricyclohexylphosphine (280 mg, 10%) was suspended in 1,4-dioxane (4 mL) and aqueous 1M K3PO4 (2 mL). The mixture was heated to 70° C. using microwave irradiation (normal) for 45 min. The crude reaction mixture was filtered through a short plug of celite and the celite plug was washed with EtOAc (˜50 mL). The filtrate was washed with water (2×30 mL), brine, dried over sodium sulfate, filtered and concentrated in vacuo. The resulting residue was purified by silica gel column chromatography (12 g ISCO, gradient 05-75% EtOAc in hexanes) to afford the free base of the desired product, 2-chloro-5-[2-(2,4-difluorophenoxy)-5-nitrophenyl]-4-fluoropyridine as a yellow solid (144 mg, 57%). LCMS (M+H)+=381.

Provenance & Evidence