To a mixture of 2-amino-N-(1-(6-(2,2,2-trifluoroethoxy)pyridin-3-yl)ethyl)isonicotinamide (25 mg, 0.073 mmol, Step-1, single enantiomer) and pyridine (0.024 mL, 0.29 mmol) in N,N-dimethylacetamide (1 mL) is added isobutyryl chloride (16 mg, 0.15 mmol) at room temperature. After stirring at room temperature for 2 hours, the mixture is poured onto water (2 mL), and the mixture is extracted with ethyl acetate (3 mL). The organic layer is dried over sodium sulfate and concentrated under reduced pressure. The residue is purified by column chromatography on NH-silica gel eluting with ethyl acetate and then by preparative LC-MS to give 12.9 mg (43% yield) of the title compound.
