9-(4-broMobutyl)-N-(2,2,2-trifluoroethyl)-9H-fluorene-9-carboxaMide

373-88-6

182438-97-7

182438-98-8

General procedure: In a three-necked flask equipped with a thermometer and a dropping funnel, 9-(4-bromobutyl)-9H-fluorene-9-carboxylic acid (25.0 g, 73 mmol), dichloromethane (250 ml), oxalyl chloride (11.0 g, 87 mmol), and DMF (5 drops) were added, and the reaction was stirred for 2 hr. at room temperature and under nitrogen protection. After completion of the reaction, the solvent was removed by evaporation under reduced pressure. The residue was dissolved in dichloromethane (50 mL). Another 2,2,2-trifluoroethylamine hydrochloride (10.9 g, 80 mmol) and triethylamine (31 ml, 220 mmol) were dissolved in dichloromethane (100 ml), and this solution was added to the dichloromethane solution of the aforementioned residue. The reaction mixture was washed sequentially with water, 1N HCl solution, saturated aqueous NaHCO3 solution and saturated brine (200 mL each, washed 3 times), the organic phase was dried with anhydrous Na2SO4 and the solvent was removed by evaporation under reduced pressure. The residue was purified by silica gel column chromatography (eluent: appropriate ratio of hexane/ethyl acetate) to give a light yellow oil. The oil was recrystallized from anhydrous ethanol (200 mL) at -5 °C and the solid was collected to give 9-(4-bromobutyl)-N-(2,2,2-trifluoroethyl)-9H-fluorene-9-carboxamide (23.7 g, 76.1% yield) as a white solid.