HOBt (34 mg, 0.25 mmol) and DIPEA (67.9 mg, 0.51 mmol) were added to a stirred solution of 3-fluorobenzoic acid (29 mg, 0.21 mmol) in DMF (1.5 mL). The reaction mixture was cooled to 10° C. and EDCI.HCl (48 mg, 0.25 mmol) followed by N-biphenyl-4-yl-3-oxo-3-piperazin-1-yl-propionamide hydrochloride (75 mg, 0.2 mmol) were added. The reaction mixture was stirred at room temperature overnight then diluted with water. The resulting precipitate was filtered and dried to afford 91 mg (98%) of N-biphenyl-4-yl-3-[4-(3-fluoro-benzoyl)-piperazin-1-yl]-3-oxo-propionamide. LCMS: 446.18 (M+1)+ 98.1%, 1H NMR: (CDCl3): δ 9.6 (s, 1H), 7.6 (m, 6H), 7.46 (m, 3H), 7.34 (m, 1H), 7.16 (m, 3H), 3.7 (bs, 7H), 3.54 (s, 3H).
