Hydrochloric Acid → 9-Phenyl-9H-carbazole-3-boronic acid

HRID 926679Notes

Reaction equation

HRID 926679 reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]2[N:6]([C:15]3[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=3)[C:7]3[C:12]([C:13]=2[CH:14]=1)=[CH:11][CH:10]=[CH:9][CH:8]=3.CCCCCC.C([Li])CCC.[B:32](OC)([O:35]C)[O:33]C.Cl>C1COCC1>[C:7]1([N:6]2[C:5]3[CH:13]=[CH:14][C:2]([B:32]([OH:35])[OH:33])=[CH:3][C:4]=3[C:20]3[C:15]2=[CH:16][CH:17]=[CH:18][CH:19]=3)[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 189426243-Bromo-9-phenylcarbazoleHCID 178418244HCID 178418244, compound

Product 1

HCID 513584509-Phenyl-9H-carbazole-3-boronic acidYield 58.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

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 mmol/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.

Workup

  1. stirringstirring
  2. waitwas continued for 24 hours
  3. stirringadditional stirring
  4. waitwas conducted for 1 hour at room temperature
  5. extractionAfter the solution was extracted with ethyl acetate
  6. washthe organic layer was washed with brine
  7. dry with materialdried with magnesium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customThe resulting solid was recrystallized with a mixed solvent of chloroform and hexane

Sources & evidence

ORD record
ord-0b33b73711524bcc8ae8979ef7fcfab3
Source dataset
uspto-grants-2016_03
Patent number
US09287511B2

Reaction notes

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