To a mixture of 4-methoxy-3-methyl phenylboronic acid (0.32 g, 1.95 mmol), ligand TFP (0.06 g, 0.26 mmol), Pd2dba3 (0.12 g, 0.13 mmol), copper (I) thiophene-2-carboxylate (0.37 g, 2.0 mmol) was added a solution of (4-phenylsulfanylcarbonyl-piperidin-1-yl)-acetic acid ethyl ester (0.4 g, 1.3 mmol) in 6 mL of DME. It was stirred at RT for 16 hours, the reaction mixture was diluted with ethyl acetate, filtered through celite then concentrated in vacuo. Purification by flash chromatography gave the title compound (0.2 g, 0.6 mmol). MS (ESI) m/z 319.8 (M+H+); HPLC (Novapak 150×3.9 mm C-18 column: mobile phase: 35-90% acetonitrile/water with 0.1% TFA, at 2 mL/min over 2 min.) t 1.36 min.
