反应详情

Methyl 2-(2,4-difluorobenzyl)isonicotinate (7.011 g, 26.63 mmol) was dissolved in acetic acid (50 mL) and platinum(IV) oxide (0.302 g, 1.33 mmol) added. The resulting mixture was hydrogenated in a Büchi hydrogenator for 4.5 h at room temperature and 5 bar. platinum(IV) oxide (174 mg) was added and the hydrogenation continued at room temperature at 5 bar for 2 h. Additional platinum(IV) oxide (185 mg) was added and the hydrogenation continued at room temperature at 5 bar for 2 h. The catalyst was filtered off and washed with MeOH and the eluate evaporated. DCM and 10% K2CO3 were added and the phases separated. The water phase was extracted with DCM and the combined organic phase washed with water, passed through a phase separator and evaporated to yield methyl 2-(2,4-difluorobenzyl)-piperidine-4-carboxylate (7.103 g, 99%) as a yellow oil. MS m/z 270 (M+H)+

1. waitthe hydrogenation continued at room temperature at 5 bar for 2 h
2. waitthe hydrogenation continued at room temperature at 5 bar for 2 h
3. filtrationThe catalyst was filtered off
4. washwashed with MeOH
5. additionDCM and 10% K2CO3 were added
6. customthe phases separated
7. extractionThe water phase was extracted with DCM
8. washthe combined organic phase washed with water
9. customevaporated