Reaktion #157742

Reaktionsgleichung

2,2-dimethyl-1,3-propanediol

4-bromo-2-methylbenzotrifluoride

n-butyllithium

triisopropyl borate

→

title compound

Ausbeute 62.0%

5,5-Dimethyl-2-[3-methyl-4-(trifluoromethyl)phenyl]-1,3,2-dioxaborinane

Ausbeute 62.0%

Lösungsmittel

Acetic acid

Water

tetrahydrofuran

hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe mixture was stirred at room temperature overnight
2. 2
   workup.STIRRINGby stirring at room temperature for three hours
3. 3
   Extraktionfollowed by extraction with ethyl acetate
4. 4
   WaschenThe organic layer was washed with water and brine
5. 5
   Trocknendried over anhydrous magnesium sulfate
6. 6
   Filtrationfiltered
7. 7
   SonstigeThe solvent was then evaporated under reduced pressure
8. 8
   SonstigeThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=10:1)

Vorschrift

A solution of 4-bromo-2-methylbenzotrifluoride (500 mg) in tetrahydrofuran (5 mL) was cooled to an external temperature of −78° C. in a nitrogen atmosphere, and a solution of n-butyllithium in hexane (1.57 M, 2.0 mL) was added dropwise. After stirring at −78° C. for 30 minutes, triisopropyl borate (0.72 mL) was added dropwise and the mixture was stirred at room temperature overnight. Acetic acid (0.18 mL) and 2,2-dimethyl-1,3-propanediol (240 mg) were added, followed by stirring at room temperature for three hours. Water was added to the reaction solution, followed by extraction with ethyl acetate. The organic layer was washed with water and brine, dried over anhydrous magnesium sulfate and filtered. The solvent was then evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=10:1) to give the title compound as a colorless solid (353 mg, 62%).

Quelle