Methyl 3-phenylpropionate → N-methoxy-N-methyl-3-phenylpropanamide

HRID 593404

Reaktionsgleichung

Reaktionsgleichung von HRID 593404
Cl.[CH3:2][NH:3][O:4][CH3:5].C[Al](C)C.[C:10]1([CH2:16][CH2:17][C:18]([O:20]C)=O)[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1>C1(C)C=CC=CC=1>[CH3:5][O:4][N:3]([CH3:2])[C:18](=[O:20])[CH2:17][CH2:16][C:10]1[CH:11]=[CH:12][CH:13]=[CH:14][CH:15]=1

Komponenten

5

Edukt 3

HCID 7643Methyl 3-phenylpropionateHCID 81138Methanamine, N-methoxy-, hydrochloride (1:1)HCID 16682925Trimethylaluminum

Produkt 1

HCID 3785569N-methoxy-N-methyl-3-phenylpropanamide

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 1140TolueneLösungsmittel2×

Versuchsvorschrift

Following a procedure of Trost (Trost, B. M. et al., J. Am. Chem. Soc. 128, 6745-6754 (2006)); to a slurry of N,O-dimethylhydroxylamine hydrochloride (4.91 g, 50.4 mmol, 2.1 eq.) in toluene (50 ml) at −10° C. was added AlMe3 (2 M in hexanes, 25.2 ml, 50.4 mmol, 2.1 eq.) dropwise. After addition, the mixture was allowed to warm to r.t. and stirred for 1 h. The mixture was cooled to −5° C. and a solution of methyl 3-phenylpropanoate 82 (3.94 g, 24.0 mmol, 1 eq.) in toluene (40 ml) was added dropwise. The reaction mixture was then allowed to warm slowly to r.t. and stirred for 3 h. The solution was cooled to 0° C. and quenched carefully by dropwise addition of HCl and the reaction mixture was extracted with EtOAc (4×70 ml). The combined organic phases were washed with brine (50 ml) before being dried (MgSO4), filtered and concentrated to give the crude product. This was purified by column chromatography on silica, eluting with petrol/EtOAc (80:20 to 75:25), giving the Weinreb amide 83 as a clear, colourless oil (4.45 g, 97%). Analytical data consistent with the literature (Trost, B. M. et al., J. Am. Chem. Soc. 128, 6745-6754 (2006); Murphy, J. A. et al., Org. Lett. 7, 1427-1429 (2005)).

Aufarbeitung

  1. additionAfter addition
  2. temperatureThe mixture was cooled to −5° C.
  3. temperatureto warm slowly to r.t.
  4. stirringstirred for 3 h
  5. temperatureThe solution was cooled to 0° C.
  6. customquenched carefully by dropwise addition of HCl
  7. extractionthe reaction mixture was extracted with EtOAc (4×70 ml)
  8. washThe combined organic phases were washed with brine (50 ml)
  9. dry with materialbefore being dried (MgSO4)
  10. filtrationfiltered
  11. concentrationconcentrated
  12. customto give the crude product
  13. customThis was purified by column chromatography on silica
  14. washeluting with petrol/EtOAc (80:20 to 75:25)

Quellen und Nachweise

ORD-Eintrag
ord-bfc84ffe17a24919b91e675767242836
Quelldatensatz
uspto-grants-2016_01
Patentnummer
US09242954B2

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