A mixture of 2-(6-chloro-5-methylpyridin-3-yl)acetic acid 86-7 (3.0 g, 16.2 mmol), 5-(pyrazin-2-yl)pyridin-2-amine 86-3 (2.80 g, 16.2 mmol), 1,3-dicyclohexylcarbodiimide (4 g, 19.44 mmol) and 4-(dimethylamino)pyridine (324 mg, 3.24 mmol) in DMF (45 mL) was stirred at room temperature for 10 hours. The reaction mixture was filtered to remove the solid and the filtrate was diluted with ethyl acetate, washed with water and brine, dried over Na2SO4 and concentrated to dryness by rotary evaporation. The crude product was purified by silica gel flash chromatography, eluted with 5% methanol in dichloromethane to give 2-(6-chloro-5-methylpyridin-3-yl)-N-(5-(pyrazin-2-yl)pyridin-2-yl)acetamide 86-8 as pale yellow solid. MS m/z 340.2 (M+1); 1H NMR 400 MHz (DMSO-d6) δ 11.09(s 1H), 9.31(d, 1H, J=1.6 Hz), 9.11(d, 1H, J=1.6 Hz), 8.72(m, 1H), 8.63(m, 1H), 8.51(dd, 1H, J1=8.6 Hz, J2=2.4 Hz), 8.21(m, 2H), 7.76(d, 1H, J=1.6 Hz), 3.82(s, 2H), 2.33(s, 3H).
