Reaktionsgleichung
[Li]CCCC.C(=O)=O.CC(C)=O.Br[C:14]1[CH:19]=[CH:18][CH:17]=[C:16]([Br:20])[N:15]=1.[CH:21](=[O:26])[CH2:22][CH2:23][CH2:24][CH3:25].CC(O)=O>C1COCC1.[NH4+].[Cl-].CO>[Br:20][C:16]1[N:15]=[C:14]([CH:21]([OH:26])[CH2:22][CH2:23][CH2:24][CH3:25])[CH:19]=[CH:18][CH:17]=1Komponenten
Edukt 5
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 3
Reaktionsbedingungen
- Temperatur
- -78 °C
Versuchsvorschrift
To a solution of nBuLi (26.40 mL of a 1.6M solution in hexanes, 42.24 mmol) in THF (25 mL) at −78° C. (dry-ice/acetone bath) was added a solution 2,6-dibromopyridine (10.00 g, 42.21 mmol) in THF (60 mL) drop-wise over 45 minutes under nitrogen. The resulting dark green coloured solution was stirred at −78° C. for 15 minutes and then valeraldehyde (6.70 mL, 63.01 mmol) was added drop-wise over 1 minute. The resulting dark purple coloured solution was stirred at −78° C. for 15 minutes and was then treated in one portion with a mixture of methanol (42 mL) and AcOH (2.70 mL, 47.16 mmol). The resulting pale yellow coloured solution was then allowed to warm to rt slowly over 1 hour. The mixture was then diluted with saturated aqueous NH4Cl (200 mL) and the product extracted with EtOAc (2×200 mL). The combined organic layer was then washed with brine (250 mL), dried (MgSO4), filtered and reduced to an orange oil (10.31 g, 100%). Purification of 7.14 g of this material by Biotage™ chromatography (silica) eluting with cyclohexane:EtOAc (gradient 100:1 to 1:1) afforded the title compound as a clear, pale yellow oil (4.48 g).
Aufarbeitung
- stirringThe resulting dark purple coloured solution was stirred at −78° C. for 15 minutes
- temperatureto warm to rt slowly over 1 hour
- extractionthe product extracted with EtOAc (2×200 mL)
- washThe combined organic layer was then washed with brine (250 mL)
- dry with materialdried (MgSO4)
- filtrationfiltered
- customPurification of 7.14 g of this material by Biotage™ chromatography (silica)
- washeluting with cyclohexane
Quellen und Nachweise
- ORD-Eintrag
- ord-11c0c5c9eabe419d891c0cdab7b0e271
- Quelldatensatz
- uspto-grants-2008_03
- Patentnummer
- US07338960B2
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