2-Nitrofluorobenzene (0.14 g) was added to a mixture of 1-[4-(2-dimethylaminoethoxy)phenyl]-3-(4-hydroxyphenyl)-1,3-dihydroimidazol-2-one (0.34 g), Aliquat® 336 (0.04 g, tricaprylylmethylammonium chloride), potassium hydroxide (0.077 g) and toluene (10 mL). The mixture was heated under reflux for 3 hours. After cooling, the reaction solution was washed with water, dried and concentrated. The residue was purified by preparative HPLC. The product with the molecular weight of 460.49 (C25H24N4O5); MS (ESI): 461 ([M+H]+), was obtained as hydrotrifluoroacetate in this way.
