Reaktion #77592

Reaktionsgleichung

sulfuric acid

3-bromobenzonitrile

triisopropoxyborane

sodium hydroxide

n-butyllithium hexane

→

title compound

Ausbeute 72.0%

Dihydroxy-(3-cyanophenyl)borane

Ausbeute 72.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGAfter stirring at room temperature for 30 min.
2. 2
   Temperaturit was cooled to 0° C.
3. 3
   TemperaturThis solution was refluxed
4. 4
   Temperaturwith heating overnight
5. 5
   Temperaturcooled to 0° C. again
6. 6
   Extraktionextracted with 200 ml of diethyl ether
7. 7
   SonstigeThe aqueous layer was removed
8. 8
   workup.ADDITION6M hydrochloric acid was added until the pH was 2
9. 9
   ExtraktionIt was extracted twice with 300 ml of ethyl acetate
10. 10
    Trocknendried with magnesium sulfate
11. 11
    Sonstigethe solvent was removed
12. 12
    SonstigeThe resulting crude product was recrystallized from DMF-water

Vorschrift

20 g of 3-bromobenzonitrile was dissolved in 100 ml of dry THF and, under a nitrogen atmosphere, 37.6 ml of triisopropoxyborane was added. This solution was cooled to −78° C., and 98.3 ml of 1.6M n-butyllithium hexane solution was dropped for 30 min. with stirring. After stirring at room temperature for 30 min., it was cooled to 0° C., 220 ml of 4M sulfuric acid was added. This solution was refluxed with heating overnight, and then cooled to 0° C. again. 340 ml of 5M sodium hydroxide was added, and extracted with 200 ml of diethyl ether. The aqueous layer was removed, and 6M hydrochloric acid was added until the pH was 2. It was extracted twice with 300 ml of ethyl acetate, dried with magnesium sulfate, and then the solvent was removed. The resulting crude product was recrystallized from DMF-water to produce 11.6 g (72%) of the title compound as acicular light-yellow crystals.

Quelle