反应详情

To a stirred solution of 1,1-dimethylethyl 4-[2-methyl-5-(methyloxy)-4-nitrophenyl]-1-piperazinecarboxylate (4.8 g, 13.67 mmol) in 80 mL of dichloromethane was added trifluoroacetic acid (˜5.5 mL). The mixture stirred at room temperature for 24 hours. The solvent was rotovaped down. The crude product was taken up in 50 mL of methanol and neutralized with 0.5 N sodium methoxide. 12 g of Silica gel was added and the solvent was rotovaped down. The crude product was purified by flash chromatography to give 1-[2-methyl-5-(methyloxy)-4-nitrophenyl]piperazine (3.43 g, 13.53 mmol, 98%). 1H NMR (400 MHz, DMSO-d6) δ ppm 7.75 (s, 1 H), 6.69 (s, 1 H), 3.88 (s, 3 H), 3.08-3.18 (m, 8 H), 2.15-2.21 (m, 3 H).

1. addition12 g of Silica gel was added
2. customThe crude product was purified by flash chromatography