反应详情

Methyl 2-(3,4-difluorobenzyl)isonicotinate (7.7 g, 29.25 mmol) was dissolved in acetic acid (75 mL) and platinum(IV) oxide (0.332 g, 1.46 mmol) added. The resulting mixture was hydrogenated in a Büchi hydrogenator at room temperature and 5 bar for 4 h 45 min. More platinum(IV) oxide (0.166 g, 0.73 mmol) was added and the hydrogenation continued at 5 bar for 2 h. More platinum(IV) oxide (0.166 g, 0.73 mmol) was added and the hydrogenation continued at 5 bar for 1 h 20 min. The catalyst was filtered off and washed with MeOH and the eluate evaporated. DCM and 10% K2CO3 were added and the phases separated. The organic layer was washed with brine, passed through a phase separator and evaporated to yield crude methyl 2-(3,4-difluorobenzyl)piperidine-4-carboxylate (8.133 g, 103%) as a brown oil. MS m/z 270 (M+H)+

1. customwas hydrogenated in a Büchi hydrogenator at room temperature
2. waitthe hydrogenation continued at 5 bar for 2 h
3. waitthe hydrogenation continued at 5 bar for 1 h 20 min
4. filtrationThe catalyst was filtered off
5. washwashed with MeOH
6. additionDCM and 10% K2CO3 were added
7. customthe phases separated
8. washThe organic layer was washed with brine
9. customevaporated