Potassium Bromide → (S)-2-methyl-3-quinoxalin-6-yl-propionaldehyde

HRID 988749

Reaktionsgleichung

Reaktionsgleichung von HRID 988749
[CH3:1][C@@H:2]([CH2:5][C:6]1[CH:7]=[C:8]2[C:13](=[CH:14][CH:15]=1)[N:12]=[CH:11][CH:10]=[N:9]2)[CH2:3][OH:4].CC1(C)N([O])C(C)(C)CCC1.[K+].[Br-].Cl[O-].[Na+].C([O-])(O)=O.[Na+]>C1(C)C=CC=CC=1.O>[CH3:1][C@@H:2]([CH2:5][C:6]1[CH:7]=[C:8]2[C:13](=[CH:14][CH:15]=1)[N:12]=[CH:11][CH:10]=[N:9]2)[CH:3]=[O:4]

Komponenten

8

Edukt 5

HCID 253877Potassium BromideHCID 516892Sodium BicarbonateHCID 2724126TempoHCID 23665760Sodium Hypochlorite2×HCID 69709252(S)-2-methyl-3-quinoxalin-6-yl-propan-1-ol

Produkt 1

HCID 86588589(S)-2-methyl-3-quinoxalin-6-yl-propionaldehyde

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 962WaterLösungsmittel2×HCID 1140TolueneLösungsmittel

Versuchsvorschrift

A solution of crude (S)-2-methyl-3-quinoxalin-6-yl-propan-1-ol (3.68 g, 18.19 mmol) in toluene (37 ml) is treated with TEMPO (28.4 mg, 0.152 mmol) and KBr (216.5 mg, 1.82 mmol) in 0.9 ml water. 37 ml of a 0.5 M sodiumhypochlorite solution of pH 8-9 (prepared by mixing 34 ml 0.75 M sodiumhypochlorite solution with 16 ml water and 0.85 g NaHCO3) is added dropwise over 20 minutes at 5° to 8°. After 5 minutes stifling at 0°, the two phase mixture is filtered over Hyflo, the phases separated, the organic phase washed with a solution of 116 mg KI in 15 ml 1 N HCl, then 15 ml of a 5% Na2S2O3 solution and finally 15 ml brine. Drying over Na2SO4 and evaporation afford crude aldehyde. MPLC purification (silicagel, EtOAc/hexane 2:1) yield pure (S)-2-Methyl-3-quinoxalin-6-yl-propionaldehyde as a slightly yellow clear oil. TLC (silicagel, EtOAc/hexanes 2:1): rf 0.37.

Aufarbeitung

  1. additionis added dropwise over 20 minutes at 5° to 8°
  2. filtrationthe two phase mixture is filtered over Hyflo
  3. customthe phases separated
  4. washthe organic phase washed with a solution of 116 mg KI in 15 ml 1 N HCl
  5. dry with materialDrying over Na2SO4 and evaporation
  6. customafford crude aldehyde
  7. customMPLC purification (silicagel, EtOAc/hexane 2:1)

Quellen und Nachweise

ORD-Eintrag
ord-e866dcd34a5f45ed84f6a4be0e9be93f
Quelldatensatz
uspto-grants-2003_10
Patentnummer
US06635647B2

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