Reaktion #2348085

Reaktionsgleichung

trimethyl borate

hydrochloric acid

THF

sec-butyl lithium

→

phenylboronic acid

Lösungsmittel

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITthe stirring was continued for additional 180 minutes
2. 2
   SonstigeThe resulting reaction mixture
3. 3
   Sonstigeto come to 0° C.
4. 4
   workup.ADDITIONpoured into a vessel
5. 5
   Temperaturhad been chilled at 0° C.
6. 6
   workup.ADDITIONmixed
7. 7
   Sonstigeto be separated into an organic layer
8. 8
   ExtraktionExtraction
9. 9
   WaschenThe extracts were washed with brine
10. 10
    Trocknendried over anhydrous magnesium sulfate
11. 11
    workup.DISTILLATIONThen, the solvent was distilled off under reduced pressure

Vorschrift

The compound (T17) and THF (1,000 ml) were put into a reaction vessel under an atmosphere of nitrogen, and chilled to −71° C. Then, a sec-butyl lithium solution (1.0 M in cyclohexane and n-hexane; 1,000 ml) were added dropwise thereto in the temperature range of −71° C. to −62° C., and the stirring was continued for additional 120 minutes. Subsequently, trimethyl borate (127.6 g) was added dropwise in the temperature range of −70° C. to −59° C., and the stirring was continued for additional 180 minutes. The resulting reaction mixture was allowed to come to 0° C., and then poured into a vessel containing 1N-hydrochloric acid (3,000 ml) and ethyl acetate (3,000 ml) which had been chilled at 0° C. and mixed. The mixture was then allowed to stand to be separated into an organic layer and an aqueous layer. Extraction was carried out and the resulting organic layer was fractionated. The extracts were washed with brine, and dried over anhydrous magnesium sulfate. Then, the solvent was distilled off under reduced pressure, whereby 115.9 g of phenylboronic acid derivative (T18) was obtained.

Quelle