To a solution of 5-amino-1-[bis(4-fluorophenyl)methyl]-1H-pyrrole-3-carbonitrile (13.9 g, 45.1 mmol) in ethanol (200 ml) was sequentially added acetylacetone (5.02 g, 50.2 mmol) and concentrated hydrochloric acid (2.0 ml). The mixture was heated under reflux for 3 hours, poured into saturated sodium bicarbonate solution and extracted with ethyl acetate. The extract was washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to give the objective product as a solid material.
