The 2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-propionic acid (prepared as in PCT WO 2004/052869 A1, Example 1, 100 mg, 0.30 mmol) was dissolved in chloroform (1 mL). To this solution was added a 2.0 M solution of oxalylchloride in methylene chloride (151 μL, 0.30 mmol) and N,N-dimethylformamide (23 μL, 0.30 mmol). The solution was allowed to stir for 1 h at 25° C., after which 1H-pyrazol-3-ylamine (25 mg, 0.30 mmol) was added along with 2,6-lutidine (70 μL, 0.60 mmol). The reaction was allowed to proceed for 40 h. The solvent was removed in vacuo and the crude material was purified by reverse phase preparative HPLC (Column: Thomson C18 ODSA, 5 micron, 50×21.2 mm ID; 30% acetonitrile/water to 100% acetonitrile/water; 30 mL/min flow rate for 15 min run) afforded 2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-N-(1H-pyrazol-3-yl)-propionamide (52 mg, 43%) as a white solid: ESI-LRMS m/e calcd for C18H22ClN3O3S [M+] 395.1, found 396.1 [M+H+]; 1H NMR (400 MHz, CDCl3) δ ppm 1.00-1.19 (m, 2H, CH2), 1.34-1.91 (m, 8H, 4×CH2), 2.08-2.29 (m, 1H, CH), 3.24 (s, 3H, SO2CH3), 3.65 (t, J=7.6 Hz, 1H, CH), 6.54 (d, 1H, J=1.7, Ar), 7.39 (m, 2H, Ar), 7.54 (d, Jm=1.3 Hz, 1H, Ar), 7.94 (d, Jo=8.2 Hz, 1H, Ar), 9.26 (s, 1H, NH).
