反应详情

温度

0 °C

Ammonium acetate (33 g) was added to the stirred solution of 1-carbethoxy-3-ethyl-4-piperidinone (8.2 g, 41 mmol) in methanol (125 ml) and stirring was continued for 3 hr at ambient temperature. The resulting mixture was cooled at 0° C. and sodium cyanoborohydride (2.5 g, 39 mmol) was added to it. Cooling was removed after 10 min. and resulting mixture was stirred for 6 hr at ambient temperature. The reaction mixture was concentrated to dryness, triturated with water, acidified with conc. HCl (pH 3˜4) and extracted with ethyl acetate to remove impurities. The aqueous layer was basified with 1 M sodium hydroxide solution (pH˜10) and extracted with ethyl acetate. Ethyl acetate extract was dried (Na2SO4) and concentrated to dryness to furnish crude 4-amino-1-carbethoxy-3-ethylpiperidine, which was used as such in the next step. 4-Amino-1-carbethoxy-3-ethylpiperidine was suspended in 5 M NaOH solution (36 ml), stirred at 120° C. for 120 hr, cooled, extracted with ethyl acetate, dried (Na2SO4) and concentrated to dryness to afford 4-amino-3-ethylpiperidine. Yield 3.1 g (59.6%), C7H16N2, m/z 129 (M+1).

1. temperatureCooling
2. customwas removed after 10 min.
3. customresulting mixture
4. stirringwas stirred for 6 hr at ambient temperature
5. concentrationThe reaction mixture was concentrated to dryness
6. customtriturated with water
7. extractionextracted with ethyl acetate
8. customto remove impurities
9. extractionextracted with ethyl acetate
10. extractionEthyl acetate extract
11. dry with materialwas dried (Na2SO4)
12. concentrationconcentrated to dryness