A microwave vial (2 ml) was charged with (S)-3-(4-{2-amino-6-[(S)-1-(4-bromo-phenyl)-2,2,2-trifluoro-ethoxy]-pyrimidin-4-yl}-phenyl)-2-tert-butoxycarbonylamino-propionic acid (139 mg, 0.23 mmol), 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-isoxazole (57.5 mg, 0.3 mmol), 1 ml of acetonitrile, and 0.7 ml of water. To this mixture was added 0.4 ml of aqueous sodium carbonate (1M), followed by 14 mg of dichlorobis-(triphenylphosphine)-palladium(II). The reaction vessel was sealed and heated to 150° C. for 5 minutes with microwave irradiation. After cooling, the reaction mixture was evaporated to dryness, the residue was dissolved in 2.5 ml of methanol and was purified by preparative HPLC to give 20 mg of (S)-3-(4-{2-amino-6-[(S)-2,2,2-trifluoro-1-(4-isoxazol-4-yl-phenyl)-ethoxy]-pyrimidin-4-yl}-phenyl)-2-tert-butoxycarbonylamino propionic acid.
