Citric Acid → Tert-butyl 4-phenyl-2-(4-phenylpyridine-2-carboxamido)benzoate

Participants

Reaction Steps

Phenylboranic acid (21 mg), tripotassium phosphate (69 mg), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (1.2 mg), and palladium(II) acetate (1.3 mg) were added to a toluene (1.2 mL) solution of tert-butyl 2-(4-chloropyridine-2-carboxamido)-4-phenylbenzoate (60 mg), followed by heating to reflux under a nitrogen atmosphere for 3 hours. The reaction mixture was cooled to room temperature, and then phenylboranic acid (5.4 mg), tripotassium phosphate (16 mg), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (1.2 mg), and palladium(II) acetate (1.3 mg) were added thereto, followed by heating to reflux under a nitrogen atmosphere for 2 hours. The reaction mixture was cooled to room temperature, and then ethyl acetate and a 10% aqueous solution of citric acid were added thereto. The insoluble substance was removed by filtration. The organic layer was separated, washed with a saturated aqueous solution of sodium chloride, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The obtained residue was purified by silica gel column chromatography [Fuji Silysia Chemical Ltd., PSQ100B (spherical), eluent: 100-85% hexane/ethyl acetate] to obtain 65 mg of tert-butyl 4-phenyl-2-(4-phenylpyridine-2-carboxamido)benzoate as a colorless oily substance.

Provenance & Evidence