反应详情

A solution of conc. H2SO4 (2.65 mL) in AcOH (40 mL) and a solution of conc. HNO3 (2.1 mL) in AcOH (20 mL) are added sequentially and dropwise to a solution of 4-phenylpiperidine in AcOH (40 mL), maintaining the temperature below 20° C. Then, conc. H2SO4 (40 mL) is added (no cooling applied; internal temperature reaches 60° C.). The reaction mixture is allowed to cool to RT, poured onto ice/water (100 g), neutralized by addition of solid NaHCO3 (150 g), and extracted with DCM. The organic phase is washed with brine, dried (Na2SO4), filtered and concentrated. The residue is purified by trituration in Et2O to afford the title compound as a yellow solid. ESI-MS: 207.1 [MH]+; tR=2.42 min (system 1).

1. temperaturemaintaining the temperature below 20° C
2. customreaches 60° C.
3. additionpoured onto ice/water (100 g)
4. extractionextracted with DCM
5. washThe organic phase is washed with brine
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue is purified by trituration in Et2O