A solution of (1,5-dimethyl-3-phenyl-1H-pyrrol-2-yl)-oxo-acetyl chloride (46 g, 0.176 mol) in dry dichloromethane (300 mL) was added to a solution of 4-[4-(4,6-dimethyl-pyridin-2-yl)-piperazin-1-yl]-phenylamine (40 g, 0.140 mol) and triethylamine (14.2 g, 0.140 mol) in dry dichloromethane (300 mL) over 15 min. After stirring for 1 h the reaction mixture was quenched into water (200 mL) and the organic phase separated. The aqueous layer was extracted with dichloromethane (2×50 mL) and the combined organic layers were washed successively with water (2×200 mL), brine (2×100 mL), dried over anhydrous sodium sulfate and concentrated to give a solid. This was dissolved in acetone (580 mL) and silica gel was added (72.5 g, 100-200 mesh). The mixture was stirred at room temperature for 1 h, filtered and the solids washed with acetone (75 mL). The silica treatment was repeated a second time. The filtrate was concentrated to ˜300 mL (˜4 vols), activated carbon (8 g) was added and heated at reflux for 15 min. The mixture was cooled to 45-50° C. and filtered over celite, washing with acetone (75 mL). The solution was again concentrated to ˜300 mL and petroleum ether (725 mL, 10 vols) was added, slowly, at reflux. The resulting suspension was cooled to room temperature, stirred for 15 min, then cooled to 0° C. and stirred for 1 h. The solid was filtered off, washed with petroleum ether (150 mL) and dried under vacuum to afford 2-(1,5-dimethyl-3-phenyl-1H-pyrrol-2-yl)-N-{4-[4-(4,6-dimethyl-pyridin-2-yl)-piperazin-1-yl]-phenyl}-2-oxo-acetamide (53.5 g, 74%) as a yellow solid.
