Potassium Carbonate → Carbazole

HRID 2405664Notes

Reaction equation

HRID 2405664 reaction equation
Br[C:2]1[CH:14]=[CH:13][C:12]2[C:11]3[C:6](=[CH:7][C:8](Br)=[CH:9][CH:10]=3)[N:5](CCCCCCCC)[C:4]=2[CH:3]=1.C1C2NC3C(=CC=CC=3)C=2C=CC=1B1OC(C)(C)C(C)(C)O1.C([O-])([O-])=O.[K+].[K+]>[Cl-].C([N+](CC)(CC)CC)C1C=CC=CC=1.C1(C)C=CC=CC=1>[CH:3]1[C:4]2[NH:5][C:6]3[C:11](=[CH:10][CH:9]=[CH:8][CH:7]=3)[C:12]=2[CH:13]=[CH:14][CH:2]=1

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 467380132-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazoleHCID 669790572,7-Dibromo-9-n-octylcarbazole

Product 1

HCID 6854Carbazole

Reagents, catalysts & solvents 2

HCID 66133Benzyl triethylammonium chlorideCatalystHCID 1140TolueneSolvent

Procedure

A solution of 2,7-dibromo-9-octyl-9H-carbazole (220 mg, 0.5 mmol), 9H-carbazole-2-boronic acid pinacol ester (880 mg, 1.5 mmol) and benzyltriethylammonium chloride (50 mg) in a mixture of toluene (20 mL) and aqueous K2CO3 (2M, 8 mL) was degassed by three freeze-pump-thaw cycles. Pd(PPh3)4 (5 mg) was added under argon and degassed by three freeze-pump-thaw again. The mixture was refluxed for 24 h and the organic phase was separated and evaporated. The product was purified by column chromatography (hexane/THF, 4:2) and dried in vacuum. A 220 mg (71%) yield of trimer carbazole was obtained as a light brown powder. 1H NMR (THF-d8, 500 MHz): δ=10.33 (s, 2H), 8.15 (m, 4H), 8.07 (d, J=7.9, 2H), 7.82 (m, 4H), 7.6 (m, 4H), 7.43 (d, J=8.0, 2H), 7.34 (m, 2H), 7.15 (m, 2H), 4.56 (t, J=7.19, 2H), 1.99 (m, 2H), 1.29 (m, 10H), 0.83 (t, J=6.9, 3H). MALDI-TOF MS: m/z 609.33 (100%).

Workup

  1. customwas degassed by three freeze-pump-thaw cycles
  2. additionPd(PPh3)4 (5 mg) was added under argon
  3. customdegassed by three freeze-pump-thaw again
  4. temperatureThe mixture was refluxed for 24 h
  5. customthe organic phase was separated
  6. customevaporated
  7. customThe product was purified by column chromatography (hexane/THF, 4:2)
  8. customdried in vacuum

Sources & evidence

ORD record
ord-e97cf88217794cefac9d7d15ffd3522f
Source dataset
uspto-grants-2014_08
Patent number
US08809063B2

Reaction notes

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