Benzene → n-Ethyl-3-(3-bromophenyl)carbazole

HRID 452357Notes

Reaction equation

HRID 452357 reaction equation
[CH2:1]([N:3]1[C:15]2[CH:14]=[CH:13][C:12](Br)=[CH:11][C:10]=2[C:9]2[C:4]1=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH3:2].[Br-:17].[Li+].[CH:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1.O>CCOCC.C1C=CC(P(C2C=CC=CC=2)CCCP(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.Cl[Pd]Cl>[CH2:1]([N:3]1[C:15]2[CH:14]=[CH:13][C:12]([C:19]3[CH:24]=[CH:23][CH:22]=[C:21]([Br:17])[CH:20]=3)=[CH:11][C:10]=2[C:9]2[C:4]1=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH3:2]

Participants

7

Reactant 4

HCID 241BenzeneHCID 962WaterHCID 82050Lithium BromideHCID 6210803-Bromo-9-ethylcarbazole

Product 1

HCID 67341776n-Ethyl-3-(3-bromophenyl)carbazoleYield 29.2%

Reagents, catalysts & solvents 2

HCID 11017392(1,3-Bis(diphenylphosphino)propane)palladium(II) chlorideCatalystHCID 3283Diethyl EtherSolvent2×

Conditions

Temperature
-78 °C

Procedure

1.00 g of N-ethyl-3-bromocarbazole was dissolved in 3.2 ml of dehydrated ether in a Schrenck tube which was flame-dried and argon gas-replaced. This solution was cooled to −78° C., and 2.4 ml of n-butyl lithium (2.64M hexane solution) was added dropwise. After raising the temperature to 0° C., and stirring for 1 hour, it was cooled again to −78° C., an ether solution of magnesium bromide prepared from magnesium 0.4 g and 1,2-dibromoethane 0.8 g was added dropwise. After raising the temperature to room temperature and stirring for 12 hours, this reaction solution was added dropwise into a solution which was prepared by suspending lithium bromide 0.28 g, 3-trifluoromethanesulfoxybromo benzene 0.82 g, and dichloro[1,3-bis(diphenylphosphino)propane]palladium(II) 0.09 g in dehydrated diethylether 2 ml, and cooled at 0° C. After stirring for 7 hours, 20 ml water was added dropwise and partitioned. The aqueous phase was extracted twice with 40 ml toluene, and the combined aqueous phase was washed with water and saturated NaCl aqueous solution, then concentrated, and 1.61 g of crude product was obtained. It was purified with silica gel column chromatography (eluent, hexane:ethyl-acetate=25:1), 0.33 g of N-ethyl-3-(3-bromophenyl)carbazole was obtained.

Workup

  1. customwas flame-dried
  2. addition2.4 ml of n-butyl lithium (2.64M hexane solution) was added dropwise
  3. temperatureAfter raising the temperature to 0° C.
  4. temperatureit was cooled again to −78° C.
  5. customan ether solution of magnesium bromide prepared from magnesium 0.4 g and 1,2-dibromoethane 0.8 g
  6. additionwas added dropwise
  7. temperatureAfter raising the temperature to room temperature
  8. stirringstirring for 12 hours
  9. additionthis reaction solution was added dropwise into a solution which
  10. customwas prepared
  11. temperaturecooled at 0° C
  12. stirringAfter stirring for 7 hours
  13. custompartitioned
  14. extractionThe aqueous phase was extracted twice with 40 ml toluene
  15. washthe combined aqueous phase was washed with water and saturated NaCl aqueous solution
  16. concentrationconcentrated
  17. custom1.61 g of crude product was obtained
  18. customIt was purified with silica gel column chromatography (eluent, hexane:ethyl-acetate=25:1)

Sources & evidence

ORD record
ord-6bc1ae3129774a92a3dec2d54aed38d7
Source dataset
uspto-grants-2013_07
Patent number
US08492007B2

Reaction notes

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