反应详情

A stirred suspension of ethyl{trans-4-[(ethylamino)carbonyl]cyclohexyl}acetate (Step A; 740 mg; 3.07 mmol) and sodium borohydride (558 mg; 14.74 mmol) in THF (6 mL) was heated at reflux. Acetic acid (845 mL) was added dropwise over 1 h and the resultant mixture was heated at reflux for 2 h more. The reaction was cooled in an ice bath and carefully quenched with H2O (1.5 mL). 1.5NNaOH (10 mL) was added and the reaction was extracted with EtOAc (3×50 mL). The combined extracts were washed with H2O and brine (25 mL each), dried (Na2SO4), filtered and concentrated in vacuo. The residue was redissolved in EtOH (4 mL) and 4N HCl(EtOAc) (0.9 mL) was added dropwise. The reaction stirred at room temperature for 14 h. The reaction was diluted with EtOAc (30 mL) and washed successively with 2N NaOH, H2O, and brine (15 mL each). The aqueous layers were re-extracted with EtOAc (2×25 mL) and the extracts were washed with brine (15 mL). The combined organic layers were dried (Na2SO4), filtered and concentrated in vacuo to afford ethyl{trans-4-[(ethylamino)methyl]cyclohexyl}acetate as a yellow oil. LCMS=228.3 (M+1)+. 1H NMR (CDCl3, 500 MHz): δ 4.14 (q, J=7.1 Hz, 2 H), 2.66 (q, J=7.2 Hz, 2 H), 2.47 (d, J=6.9 Hz, 2 H), 2.19 (d, J=6.8 Hz, 2 H), 1.83-1.78 (m, 4 H), 1.59-1.52 (m, 2H), 1.44-1.36 (m, 2 H), 1.27 (t, J=7.1 Hz, 3 H), 1.13 (t, J=7.2 Hz, 3 H), 1.03-0.97 (m, 2 H).

1. temperaturewas heated
2. temperatureat reflux
3. temperatureat reflux for 2 h more
4. temperatureThe reaction was cooled in an ice bath
5. customcarefully quenched with H2O (1.5 mL)
6. addition1.5NNaOH (10 mL) was added
7. extractionthe reaction was extracted with EtOAc (3×50 mL)
8. washThe combined extracts were washed with H2O and brine (25 mL each)
9. dry with materialdried (Na2SO4)
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. dissolutionThe residue was redissolved in EtOH (4 mL)
13. addition4N HCl(EtOAc) (0.9 mL) was added dropwise
14. additionThe reaction was diluted with EtOAc (30 mL)
15. washwashed successively with 2N NaOH, H2O, and brine (15 mL each)
16. extractionThe aqueous layers were re-extracted with EtOAc (2×25 mL)
17. washthe extracts were washed with brine (15 mL)
18. dry with materialThe combined organic layers were dried (Na2SO4)
19. filtrationfiltered
20. concentrationconcentrated in vacuo