反应详情

t-Butyl-1-isopropylpiperidin-4-ylcarbamate (2.64 g, 10.9 mmol) obtained in Preparation Example (2-iii-1) was dissolved in methanol (20 ml) in a 250 ml vessel at 0° C., and trifluoroacetic acid (TFA; 4.06 ml, 54.5 mmol, 5 eq.) was slowly added thereto while stirring. The resulting mixture was reacted for 18 hrs. After the completion of reaction, the reaction product was concentrated under reduced pressure, subjected to azeotropic distillation with CHCl3 3 times, basified with 2N aqueous KOH solution (20 ml) and extracted with CHCl3 3 times. The organic layer was separated, washed with brine, dried, filtered and distilled under reduced pressure to obtain 1.23 g of the title compound as yellow oil (yield 79.3%).

1. customThe resulting mixture was reacted for 18 hrs
2. customAfter the completion of reaction
3. concentrationthe reaction product was concentrated under reduced pressure
4. distillationsubjected to azeotropic distillation with CHCl3 3 times
5. extractionextracted with CHCl3 3 times
6. customThe organic layer was separated
7. washwashed with brine
8. customdried
9. filtrationfiltered
10. distillationdistilled under reduced pressure