反应详情

Propyl 4-(1-tert-Butoxycarbonylamino-2-hydroxy-ethyl)-benzoate (3) (5.35 g, 16.5 mmol) was dissolved in MeOH (150 mL). Argon was bubbled for 20 minutes. 5% Rh/C (1 g) was charged to the solution and argon was bubbled for another 10 minutes. The reaction mixture was stirred at 60 psi hydrogen pressure for 16 hours then at 100 psi for 7 days. Another portion of 10% Rh/C 1% Pd/C (1.2 g) was added. The reaction mixture was stirred at 100 psi hydrogen pressure for another 7 days after which LC/MS analysis indicated complete hydrogenation of the aromatic ring. The reaction mixture was filtered through a celite bed and rinsed with MeOH. The filtrate was concentrated under vacuum to dryness. The residue was filtered through a silica gel bed and eluted with EtOAc/Hexanes (20˜40%) to give 4.9 g (89.9% yield) of the pure 1-4.

1. customArgon was bubbled for 20 minutes
2. addition5% Rh/C (1 g) was charged to the solution and argon
3. customwas bubbled for another 10 minutes
4. waitat 100 psi for 7 days
5. additionAnother portion of 10% Rh/C 1% Pd/C (1.2 g) was added
6. stirringThe reaction mixture was stirred at 100 psi hydrogen pressure for another 7 days after which LC/MS analysis
7. filtrationThe reaction mixture was filtered through a celite bed
8. washrinsed with MeOH
9. concentrationThe filtrate was concentrated under vacuum to dryness
10. filtrationThe residue was filtered through a silica gel bed
11. washeluted with EtOAc/Hexanes (20˜40%)
12. customto give 4.9 g (89.9% yield) of the pure 1-4