Under a nitrogen stream, to a mixture of 4-(2,4-dichlorophenyl)piperazine-1-carboxylic acid tert-butyl ester (3.31 g), palladium(II) acetate (0.44 g), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (0.81 g), tripotassium phosphate (11 g) and cyclopropylboronic acid (2.54 g) was added tetrahydrofuran (15 mL), and the mixture was stirred with heating under reflux. The reaction mixture was cooled, water was added, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, and the solvent was evaporated. The obtained residue was purified by column chromatography (hexane:ethyl acetate) to give the title compound (3.30 g).
