The general procedure for the synthesis of bis(9,9-dimethyl-9H-fluoren-2-yl)amine from the compound (CAS: 1185882-60-3) was as follows: 0.4 g of tert-butoxycarbonyl-protected arylamine 1 (0.8 mmol) was dissolved in 1 mL of tetrahydrofuran and 8 mL of trifluoroacetic acid (TFA). The reaction mixture was stirred at room temperature for 10 min and the color of the solution was observed to change to dark green. Subsequently, TFA was removed by evaporation under vacuum. dichloromethane was added to the residue and neutralized with saturated aqueous sodium hydroxide solution. The mixture was extracted using dichloromethane and the organic layers were combined and dried over anhydrous sodium sulfate. Purification by column chromatography (stationary phase: silica gel, mobile phase: ethyl acetate/hexane = 1:10, v/v) afforded 0.3 g of light yellow target compound 2 in 95% yield. Melting point: 178°C. 1H NMR (300 MHz, (CD3)2CO): δ 7.7-7.67 (m, 4H), 7.48 (d, J = 6.9 Hz, 2H), 7.36 (s, 2H), 7.31-7.22 (m, 4H), 7.18 (d, J = 7.2 Hz, 2H), 1.46 (s, 12H). 13C NMR (300 MHz, (CD3)2CO): δ 155.97, 153.83, 144.45, 140.29, 132.48, 127.79, 126.73, 123.27, 121.67, 119.69, 117.32, 112.46, 47.28, 27.53.
