Reaktion #81444

Reaktionsgleichung

thexylborane

boron hydride

2,3-dimethyl-1-butene

3-methyl-6-vinyloxazolo[4,5-b]pyridin-2(3H)-one

sodium hydroxide

→

6-(2-hydroxyethyl)-3-methyloxazolo[4,5-b]pyridin-2(3H)-one

Ausbeute 78.0%

Lösungsmittel

tetrahydrofuran

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturis maintained for a further 2 hours at that temperature
2. 2
   workup.STIRRINGThe whole is stirred at 0° C. for 2 hours
3. 3
   workup.STIRRINGAfter 1 hour's stirring at room temperature
4. 4
   Sonstigeevaporation of the solvent under reduced pressure
5. 5
   ExtraktionExtraction
6. 6
   Trocknenthe organic phase is dried over magnesium sulfate
7. 7
   Filtrationfiltered
8. 8
   Sonstigethe solvent is evaporated off under reduced pressure
9. 9
   SonstigePurification by flash chromatography on silica gel (eluant: dichloromethane/methanol: 95/5)

Vorschrift

A solution of boron hydride (1M in tetrahydrofuran) (5 ml, 5 mmol) is cooled using a salt/ice bath, and then 2,3-dimethyl-1-butene (0.6 ml, 5 mmol) are slowly added. The temperature of the solution is increased to 0° C. and stirring is maintained for a further 2 hours at that temperature. 3-methyl-6-vinyloxazolo[4,5-b]pyridin-2(3H)-one (1.14 mg, 5 mmol) dissolved in tetrahydrofuran (20 ml) is added to the previously prepared solution of thexylborane. The whole is stirred at 0° C. for 2 hours, then a 10% aqueous sodium hydroxide solution (2.40 ml) and also oxygenated water (2.00 ml) are added in succession. After 1 hour's stirring at room temperature and evaporation of the solvent under reduced pressure, the residue is taken up in water. Extraction is carried out with dichloromethane; the organic phase is dried over magnesium sulfate and filtered, and then the solvent is evaporated off under reduced pressure. Purification by flash chromatography on silica gel (eluant: dichloromethane/methanol: 95/5) yields 6-(2-hydroxyethyl)-3-methyloxazolo[4,5-b]pyridin-2(3H)-one in a yield of 78%.

Quelle