Реакция #1885016

Уравнение реакции

trimethyl borate

tetrahydrofuran

9-(2′-bromophenyl)-9H-carbazole

hexane

n-butyllithium

hydrochloric acid

→

powdery white solid

Выход 55.0%

4′-(9H-carbazol-9-yl)biphenyl-2-boronic acid

Выход 55.0%

Условия реакции

Обработка

1. 1
   ДругоеInto 300 mL three-neck flask were put
2. 2
   ДругоеAfter the solution was degassed under low pressure
3. 3
   workup.STIRRINGthe solution was stirred at −78° C. for 2 hours
4. 4
   workup.STIRRINGthe mixture was stirred −78° C. for 1 hour
5. 5
   workup.STIRRINGwas stirred for about 24 hours while the temperature of the mixture
6. 6
   Другоеwas being gradually brought back to room temperature
7. 7
   workup.STIRRINGthe solution was stirred for 30 minutes at a room temperature
8. 8
   workup.ADDITIONAfter the stirring, to this mixture was added
9. 9
   Экстракцияethyl acetate, and extraction with ethyl acetate
10. 10
    ЭкстракцияAfter the extraction
11. 11
    Промывкаwashed with brine
12. 12
    workup.ADDITIONAfter the washing, magnesium sulfate was added into the organic layer
13. 13
    Другоеto dry the organic layer
14. 14
    ФильтрацияAfter the drying, the mixture was subjected to suction filtration
15. 15
    Другоеto give a filtrate
16. 16
    КонцентрированиеThe obtained filtrate was concentrated
17. 17
    Другоеrecrystallized with a mixture solvent of chloroform and hexane

Методика

Into 300 mL three-neck flask were put a mixed solution of 6.2 g (16 mmol) of 9-(2′-bromophenyl)-9H-carbazole and 100 mL of tetrahydrofuran (THF). After the solution was degassed under low pressure, the atmosphere in the flask was substituted by nitrogen. The solution was stirred at −78° C. for 20 minutes. After the stirring, 12 mL (19 mmol) of hexane solution of 1.55 mol/L of n-butyllithium was dripped with a syringe, and the solution was stirred at −78° C. for 2 hours. After the stirring, 4.0 mL of trimethyl borate was added and the mixture was stirred −78° C. for 1 hour, and then was stirred for about 24 hours while the temperature of the mixture was being gradually brought back to room temperature. After the stirring, to this solution was added 50 mL of 1M dilute hydrochloric acid, and the solution was stirred for 30 minutes at a room temperature. After the stirring, to this mixture was added ethyl acetate, and extraction with ethyl acetate was performed. After the extraction, the extracted solution was combined with the organic layer and washed with brine. After the washing, magnesium sulfate was added into the organic layer to dry the organic layer. After the drying, the mixture was subjected to suction filtration to give a filtrate. The obtained filtrate was concentrated and recrystallized with a mixture solvent of chloroform and hexane to give 3.2 g of a powdery white solid in a yield of 55%.

Источник