A mixture of 2-(4-bromo-phenyl)-3-cyclopentyl-N-thiazol-2-yl-propionamide (102.5 mg, 0.27 mmol), tetrakis(triphenylphosphine)palladium(0) (15.6 mg, 0.014 mmol), 2-thiopheneboronic acid (69.2 mg, 0.54 mmol), and a 2M aqueous sodium carbonate solution (405 μL, 0.81 mmol) in 1,2-dimethoxyethane (9 mL) was heated under reflux for 24 h. The reaction mixture was allowed to cool to 25° C. and then filtered to remove the catalyst. The filtrate was concentrated in, vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 3/1 hexanes/ethyl acetate) afforded 3-cyclopentyl-N-thiazol-2-yl-2-(4-thiophen-2-yl-phenyl)-propionamide (4.5 mg, 4%) as a yellow solid: mp 194° C. (dec); EI-HRMS m/e calcd for C21H22N2OS2 (M+) 382.1174, found 382.1175.
