To a mixture of 2-chloro-4-methylthieno[3,4-b]pyridine (0.022 g), Pd2(dba)3 (0.005 g), (±)-BINAP (0.011 g), 1-((S)-3-aminopyrrolidin-1-yl)-2-(4-trifluoromethoxyphenyl)ethanone mono hydrochloride (0.046 g), and 1,4-dioxane (0.5 mL) was added sodium t-butoxide (0.045 g) under nitrogen atmosphere, and the mixture was stirred at 70° C. for 30 min. The reaction mixture was diluted with ethyl acetate and water, then the interlayer was removed by Celite filtration, and the organic layer was washed with saturated brine. The organic layer was dried with anhydrous magnesium sulfate, then the desiccant was removed by filtration, the filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (NH silica gel, ethyl acetate/methanol=20:1, and silica gel, chloroform/methanol=20:1) to obtain light yellow oily (S)-1-(3-(4-methylthieno[3,4-b]pyridin-2-ylamino)pyrrolidin-1-yl)-2-(4-trifluoromethoxyphenyl)ethanone (0.014 g).
