(2S)-2-[(5-bromopyridin-2-yl)(phenyl)methoxy]-N-(cyanomethyl)-4-methylpentanamide 、
ethyl acetate n-hexane 以to give the title compound after chromatography with 50% EtOAc/hexane的产率得到(2S)-2-[(5-bromo-1-oxidopyridin-2-yl)(phenyl)methoxy]-N-(cyanomethyl)-4-methylpentanamide