反应详情

A mixture of tert-butyl 4-[4-fluoro-3-(methoxycarbonyl)phenyl]-3,6-dihydropyridine-1(2H)-carboxylate (2.11 g, 6.29 mmol) and 10% Pd/C (525 mg) in ethanol (60 mL) was stirred under an hydrogen atmosphere using a hydrogen filled balloon for 6 h. The reaction mixture was filtered and the filtrate was concentrated. 1H NMR analysis revealed that approximately 5% of the starting olefin remained, so the mixture was resubmitted to the above conditions for 4 h. Filtration, and concentration of the filtrate gave tert-butyl 4-[4-fluoro-3-(methoxycarbonyl)phenyl]piperidine-1-carboxylate which was used without further purification. 1H NMR (500 MHz, CDCl3) δ 7.78 (dd, J=6.5, 2.0 Hz, 1H), 7.37 (m, 1H), 7.10 (dd, J=10.5, 8.0 Hz, 1H), 4.27 (br m, 2H), 3.95 (s, 3H), 2.82 (br m, 2H), 2.69 (tt, J=12.5, 3.5 Hz, 1H), 1.83 (br d, J=13 Hz, 2H), 1.62 (dq, J=4.5, 13 Hz, 2H), 1.50 (s, 9H).

1. customfor 6 h
2. filtrationThe reaction mixture was filtered
3. concentrationthe filtrate was concentrated
4. filtrationFiltration, and concentration of the filtrate