反应详情

Into a stirred solution of 5.00 g (16.0 mmol) of tert-butyl 1,2,3,6-tetrahydro-4-(3-nitrophenyl)pyridine-1-carboxylate in 100 ml of 1,4-dioxane at 0° C. was bubbled HCl gas for 10 minutes. The reaction mixture was allowed to warm to room temperature and the bubbling of the HCl gas was continued for an additional 1 hour. The solvent was removed in vacuo, the residue was dissolved in 50 mL of water and was neutralized by the addition of KOH pellets. The aqueous solution was extracted with 3×80 mL of dichloromethane and the combined organic extracts were dried (MgSO4), filtered and concentrated in vacuo. The residue was purified by column chromatography (silica, 9:1, dichloromethane:methanol+1% isopropyl amine) to afford 2.85 g (87.5% yield) of the desired product: 1H NMR (400 MHz, CDCl3) δ 8.24 (s, 1H), 8.09 (d, 1H, J=8.4 Hz), 7.71 (d, 1H, J=8.0 Hz), 7.49 (t, 1H, J=8.0 Hz), 6.35–6.25 (m, 1H), 3.58 (apparent q, 2H, J=3.0 Hz), 3.14 (t, 2H, J=5.6 Hz), 2.54–2.46 (m, 2H).

1. customthe bubbling of the HCl gas
2. customThe solvent was removed in vacuo
3. dissolutionthe residue was dissolved in 50 mL of water
4. additionwas neutralized by the addition of KOH pellets
5. extractionThe aqueous solution was extracted with 3×80 mL of dichloromethane
6. dry with materialthe combined organic extracts were dried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe residue was purified by column chromatography (silica, 9:1, dichloromethane:methanol+1% isopropyl amine)