A mixture of 1-bromo-2-methyl-4-nitrobenzene (5.16 g, 24 mmol), tert-butyl piperazine-1-carboxylate (4.46 g, 24 mmol), 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (1.15 g, 2.4 mmol), cesium carbonate (15.65 g, 48 mmol) and tris(dibenzylideneacetone)dipalladium (2.21 g, 2.4 mmol) in 1,4-dioxane (120 mL) was heated at 100° C. for 16 hours. The solid was filtered and the filtrate was concentrated to give the crude product which was purified by flash chromatography on silica gel (200-300 mesh) eluting with 20/1 petroleum ether/ethyl acetate to give the title compound. MS: 322 (M+H+).
