DIPEA (149.8 mg, 1.15 mmol) was added to a stirred solution of 2-chloro-nicotinic acid (40.5 mg, 0.26 mmol) in DMF (3 mL), HOBt (38.2 mg, 0.28 mmol) and EDCI.HCl (123.4 mg, 0.64 mmol) at room temperature. After 2 minutes biphenyl-4-carboxylicacid (2-oxo-2-piperazin-1-yl-ethyl)-amide (100 mg, 0.31 mmol) was added and the resulting mixture was stirred at room temperature overnight. Cold water was then added, and the resulting precipitate was filtered. The residue was purified by column chromatography (using 60-120 mesh silica gel and 90% EtOAc in hexane as eluent) to afford 39 mg (32.8% yield) of biphenyl-4-carboxylicacid {2-[4-(2-chloro-pyridine-3-carbonyl)-piperazin-1-yl]-2-oxo-ethyl}-amide, LC-MS purity: 89.81%, 1H NMR: (DMSO) δ 8.74-8.62 (bs, 1H), 8.56-8.46 (bs, 1H), 8.06-7.92 (d, 3H), 7.84-7.7 (q, 4H), 7.6-7.38 (m, 4H), 4.28-4.12 (d, 2H), 3.78-3.46 (bt, 6H), 3.28-3.18 (bs, 2H).
