Reaktion #1265012

Reaktionsgleichung

hydrochloric acid

n-butyllithium hexane

3-bromo-9-phenylcarbazole

trimethyl borate

→

9-phenylcarbazole-3-ylboronic acid

Ausbeute 58.5%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for 24 hours
3. 3
   workup.STIRRINGadditional stirring
4. 4
   workup.WAITwas conducted for 1 hour at room temperature
5. 5
   ExtraktionAfter the solution was extracted with ethyl acetate
6. 6
   Waschenthe organic layer was washed with brine
7. 7
   Trocknendried with magnesium sulfate
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated
10. 10
    SonstigeThe resulting solid was recrystallized with a mixed solvent of chloroform and hexane

Vorschrift

Into a solution of 19.6 g (60.7 mmol) of 3-bromo-9-phenylcarbazole, prepared in Step 1 of the Embodiment 2, in THF (100 mL) was added dropwise 66.8 mL (42.3 mmol) of an n-butyllithium hexane solution (1.58 mol/L) at −78° C. under nitrogen, which was followed by stirring for 3 hours at the same temperature. Thereafter, 13.5 mL (140 mmol) of trimethyl borate was added, and stirring was continued for 24 hours while gradually raising the reaction temperature to room temperature. 200 mL of 2.0 mol/L hydrochloric acid was added to the solution, and additional stirring was conducted for 1 hour at room temperature. After the solution was extracted with ethyl acetate, the organic layer was washed with brine, dried with magnesium sulfate, filtered, and concentrated. The resulting solid was recrystallized with a mixed solvent of chloroform and hexane, giving 10.2 g of 9-phenylcarbazole-3-ylboronic acid as white powder in 58% yield.

Quelle