A mixture of 4-(3-aminophenyl)-6-bromo-5,7-dimethyl-2H-chromen-2-one (6-4) (25 mg, 0.073 mmol), 4-(bromomethyl)phenylboronic acid (24 mg, 0.11 mmol), morpholine (30 μL, 0.35 mmol), K2CO3 (18 mg, 0.13 mmol), dichloro(1,1′-bis(diphenylphosphino)ferrocene)palladium(II)-dichloromethane adduct (6 mg, 0.007 mmol), water (0.3 mL) and 1,4-dioxane (2.7 mL) was heated in a sealed vial in a microwave reactor at 130° C. for 30 min. To the mixture was added EtOAc and water, and extracted with EtOAc. The organic layers were washed with brine, dried over Na2SO4 and concentrated. The residue was purified by silica gel column chromatography (hexanes: EtOAc=1:1˜0:1) to afford the title compound 6-5 (24 mg, 75% yield) as a yellow oil.
