Reaktion #1747830

Reaktionsgleichung

LiAlH4

3-(4-methoxyphenyl)-propionic acid n-propyl amid

→

N-(3-(4-methoxyphenyl)-propyl)-N-propylamine

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter refluxing for 12 h the mixture
2. 2
   Sonstigeexcess hydride was destroyed by careful addition of water (10 mL), 5% aqueous NaOH (40 mL) and water (20 mL)
3. 3
   Temperaturallowing reflux conditions
4. 4
   FiltrationThe hot slurry was filtered
5. 5
   Waschenthe white precipitate was washed thoroughly with ethanol
6. 6
   SonstigeVolatiles were evaporated
7. 7
   workup.DISSOLUTIONthe resulting oil dissolved in ethyl acetate (50 mL) what
8. 8
   Extraktionwas extracted with 0.5 N aqueous HCl (4×50 mL)
9. 9
   workup.ADDITIONby addition of 30% aqueous NaOH
10. 10
    Extraktionextracted with ethyl acetate (4×50 mL)
11. 11
    Waschenwashed with brine
12. 12
    Trocknendried (MgSO4)
13. 13
    Sonstigeevaporated to dryness
14. 14
    Sonstigeto give an oil that
15. 15
    Sonstigepartially crystallized in diethyl ether as the hydrochloride salt
16. 16
    SonstigeRecrystallization from acetone/diethyl ether
17. 17
    Sonstigegave white flacky crystalline material
18. 18
    SonstigeTotal yield (as free base)

Vorschrift

To a stirred mixture of LiAlH4 (8.0 g, 200 mmol) in tetrahydrofuran (100 mL) was added dropwise a solution of 3-(4-methoxyphenyl)-propionic acid n-propyl amid (10.7 g, 49 mmol) (from a) above) in tetrahydrofuran (100 mL). After refluxing for 12 h the mixture was cooled to 50° C. and excess hydride was destroyed by careful addition of water (10 mL), 5% aqueous NaOH (40 mL) and water (20 mL) allowing reflux conditions. The hot slurry was filtered and the white precipitate was washed thoroughly with ethanol. Volatiles were evaporated and the resulting oil dissolved in ethyl acetate (50 mL) what was extracted with 0.5 N aqueous HCl (4×50 mL). The acidic phase was made alkaline (pH=9) by addition of 30% aqueous NaOH and extracted with ethyl acetate (4×50 mL). The organic layers were combined, washed with brine, dried (MgSO4) and evaporated to dryness to give an oil that partially crystallized in diethyl ether as the hydrochloride salt. Recrystallization from acetone/diethyl ether gave white flacky crystalline material. Total yield (as free base): 9.9 g, 48 mmol, 98%, mp 176-177° C. IR (neat) cm−1 2960, 2772, 1611, 1514; 1H-NMR (CDCl3) δ 9.46 (br s, 1H), 7.16 (d, 2H), 6.90 (d, 2H), 3.72 (s, 3H), 2.82 (br s, 4H), 2.59 (t, 2H), 2.15 (p, 2H), 1.83 (h, 2H), 0.89 (t, 3H) ppm; 13C-NMR (CDCl3) δ 156.6, 130.3, 127.7, 112.4, 53.7, 47.9, 45.66, 30.3, 25.9, 17.8, 9.7 ppm; MS (EI) m/z 207 (M+).

Quelle