Hydrochloric Acid → 4-(9H-Carbazol-9-yl)phenylboronic Acid

HRID 2063185Notes

Reaction equation

HRID 2063185 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:20]3[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=3[C:14]3[C:9]2=[CH:10][CH:11]=[CH:12][CH:13]=3)=[CH:4][CH:3]=1.CCCCCC.C([Li])CCC.[B:32](OC)([O:35]C)[O:33]C.Cl>O1CCCC1>[CH:10]1[C:9]2[N:8]([C:5]3[CH:4]=[CH:3][C:2]([B:32]([OH:35])[OH:33])=[CH:7][CH:6]=3)[C:20]3[C:15](=[CH:16][CH:17]=[CH:18][CH:19]=3)[C:14]=2[CH:13]=[CH:12][CH:11]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 223613909-(4-Bromophenyl)carbazoleHCID 178418244HCID 178418244, compound

Product 1

HCID 231208274-(9H-Carbazol-9-yl)phenylboronic Acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

19.6 g (60.7 mmol) of N-(4-bromophenyl)carbazole synthesized in Step 1 of Example 3 was put into a 500 mL three-neck flask, and the atmosphere in the flask was substituted by nitrogen. 100 mL of tetrahydrofuran (THF) was added to the flask and cooled to −78° C. Into this solution, 66.8 mL (42.3 mmol) of n-butyllithium hexane solution (1.58 mol/L) wad dropped under a nitrogen gas flow, and the solution was stirred at the same temperature for three hours. Then, 13.5 mL (140 mmol) of trimethyl borate was added into this solution at the same temperature, and while the temperature of the solution was being increased to room temperature, the solution was stirred for about 24 hours. About 200 mL of 2.0 mol/L hydrochloric acid was added into this solution and stirred at room temperature for one hour. This solution was extracted with ethyl acetate and the extracted solution and an organic layer were washed together with a saturated brine and dried with magnesium sulfate. The mixture was filtrated, and the filtrate was concentrate to obtain a solid substance. The obtained solid substance was recrystallized with a mixed solvent of chloroform and hexane, so that 10.2 g of the white powder of 4(9H-carbazol-9-yl)phenylboronic acid was obtained in yield 58%.

Workup

  1. temperaturewhile the temperature of the solution was being increased to room temperature
  2. stirringthe solution was stirred for about 24 hours
  3. stirringstirred at room temperature for one hour
  4. extractionThis solution was extracted with ethyl acetate
  5. washthe extracted solution and an organic layer were washed together with a saturated brine
  6. dry with materialdried with magnesium sulfate
  7. filtrationThe mixture was filtrated
  8. concentrationthe filtrate was concentrate
  9. customto obtain a solid substance
  10. customThe obtained solid substance was recrystallized with a mixed solvent of chloroform and hexane, so that 10.2 g of the white powder of 4(9H-carbazol-9-yl)phenylboronic acid
  11. customwas obtained in yield 58%

Sources & evidence

ORD record
ord-37a355a375ca40b3b3c7049a50228508
Source dataset
uspto-grants-2012_10
Patent number
US08288012B2

Reaction notes

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