反应详情

3-(1-Propyl-1,4,5,6-tetrahydro-pyridin-3-yl)-cyclohex-2-enone (5.0 g, 22.8 mmol) (from b) above) was dissolved in THF (100 mL). At 0° C., acetic acid (1.38 mL, 22.8 mmol) was added followed by introduction of NaBH3CN (1.9 g, 30.0 mmol) in small portions maintaining the temperature. After the addition was complete the mixture was stirred for 1 h at this temperature and then at rt overnight. Work-up by addition of water (50 mL) and saturated aqueous NaHCO3 (50 mL) followed by extraction with dichloromethane (5×50 mL). The combined organic layers were dried (MgSO4) and evaporated. The residue was purified by column chromatography (silica, dichloromethane/ethanol 20:1) to give a colorless oil which was converted to the hydrochloride. Recrystallisation from isoprylether gave 4.2 g, 17.5 mmol (77%), mp 184–185° C. IR (KBr) 3396, 2941, 2469, 1667, 1455 cm−1; 1H-NMR (CDCl3) δ 5.83 (s, 1H), 3.85 (d, 2H), 2.29–2.56 (m, 7H), 1.23–2.17 (m, 10H), 0.88 (t, 3H) ppm; 13C-NMR (CDCl3) δ 198.4, 165.1, 123.4, 59.0, 55.6, 51.9, 41.6, 36.0, 27.3, 26.9, 22.8, 21.2, 17.6, 10.2 ppm; MS (EI) m/z 221 (M+).

1. temperaturemaintaining the temperature
2. additionAfter the addition
3. customat rt
4. customovernight
5. extractionfollowed by extraction with dichloromethane (5×50 mL)
6. dry with materialThe combined organic layers were dried (MgSO4)
7. customevaporated
8. customThe residue was purified by column chromatography (silica, dichloromethane/ethanol 20:1)
9. customto give a colorless oil which
10. customRecrystallisation from isoprylether
11. customgave 4.2 g, 17.5 mmol (77%), mp 184–185° C