反应详情

4-(2-Chloro-6-nitro-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (1.87 g, 5.47 mmol) was dissolved in trifluoroacetic acid (5.0 mL) and CH2Cl2 (5.0 mL) and allowed to stir for 2 h. The reaction mixture was concentrated, diluted with EtOAc, and washed with saturated aq. NaHCO3. The organic layer was dried over. Na2SO4, concentrated and purified by column chromatography (silica, 100% CH2Cl2) to afford 1-(2-chloro-6-nitro-phenyl)-piperazine (1.26 g, 95%). MS (electrospray): exact mass calculated for C10H12ClN3O2, 241.1; m/z found, 242.1 [M+H]+. 1H NMR (400 MHz, CDCl3): 7.54 (dd, J=8.2, 1.6 Hz, 1H), 7.49 (dd, J=8.2, 1.6 Hz, 1H), 7.10 (t, J=8.2 Hz, 1H), 3.08 (br s, 4H), 2.99 (br s, 4H), 2.07-2.12 (m, 1H).

1. concentrationThe reaction mixture was concentrated
2. additiondiluted with EtOAc
3. washwashed with saturated aq. NaHCO3
4. customThe organic layer was dried over
5. concentrationNa2SO4, concentrated
6. custompurified by column chromatography (silica, 100% CH2Cl2)