A mixture of 3-cyclopentyl-1-(2-methylphenyl)-1H-pyrazol-5-amine (Intermediate B, 400 mg, 1.66 mmol), methyl 2-bromobenzoate (297 mg, 1.38 mmol), cesium carbonate (630 mg, 1.93 mmol), BINAP (87 mg, 0.14 mmol), and Pd2(dba)3 (72 mg, 0.07 mmol) in anhydrous toluene (4 mL) was heated to 110° C. for 16 h under an argon atmosphere. The reaction mixture was cooled to rt, diluted with ethyl acetate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography using EtOAc/Hex (1:8, v/v) as the eluent. The product was obtained as a light yellow oil (303 mg, 58%). ES-MS m/z 376.3 (MH+); HPLC RT (min) 3.94.
