Potassium Hydroxide → 3-Bromo-9-ethenyl-9H-carbazole

HRID 434398Notes

Reaction equation

HRID 434398 reaction equation
BrC1C=CC2NC3C(C=2C=1)=CC=CC=3.ClCCOS(C1C(C)=CC=CC=1)(=O)=O.[OH-].[Na+].[Br:31][C:32]1[CH:33]=[CH:34][C:35]2[N:36]([CH2:45][CH2:46]Cl)[C:37]3[C:42]([C:43]=2[CH:44]=1)=[CH:41][CH:40]=[CH:39][CH:38]=3.[OH-].[K+]>CC(C)=O.O.C(OCC)C.O1CCCC1.C(O)C>[Br:31][C:32]1[CH:33]=[CH:34][C:35]2[N:36]([CH:45]=[CH2:46])[C:37]3[C:42]([C:43]=2[CH:44]=1)=[CH:41][CH:40]=[CH:39][CH:38]=3

Participants

11

Reactant 5

HCID 14797Potassium Hydroxide2×HCID 14798Sodium Hydroxide2×HCID 1134492-Chloroethyl 2-methylbenzenesulphonate2×HCID 2524463-BromocarbazoleHCID 20426783HCID 20426783, compound

Product 1

HCID 22236883-Bromo-9-ethenyl-9H-carbazoleYield 95%

Reagents, catalysts & solvents 5

HCID 180AcetoneSolventHCID 702EthanolSolventHCID 962WaterSolvent2×HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

3-Bromocarbazole (24.6 g, 0.1 mole) was dissolved in acetone. To it was added β-chloroethyltoluenesulfonate (31.68 g, 0.135 moles) and sodium hydroxide (13 g, 0.325 mole) dissolved in 10 ml of distilled water. The mixture was brought to reflux. After 24 hours, equal amounts of β-chloroethyltoluenesulfonate, sodium hydroxide, and water were added. Refluxing was continued until 3-bromo-9-(2-chloroethyl)-carbazole was formed in >95 percent yield as judged by GLPC analysis. The product was dissolved in a mixture of 250 ml diethyl ether and tetrahydrofuran (50:50 v/v) and washed successively with two 150 ml portions of distilled water and 100 ml saturated sodium chloride solution. The organic phase was separated and dried over sodium sulfate and filtered. Solvents were removed on a rotary evaporator at reduced pressure. The crude 3-bromo-9-(2-chloroethyl)carbazole was dissolved in 230 ml isopropanol. 8.4 g (0.15 mole) potassium hydroxide dissolved in 15 ml ethanol was added. The resulting solution was refluxed for 11/2 hours. 4.2 g of solid potassium hydroxide was then added, and refluxing was continued for an additional 11/2 hours. The solution was cooled in a freezer during which time a solid residue formed. After filtration, the solid was washed with water. Recrystallization from methanol gave 13.94 g 3-bromo-9-vinylcarbazole as pale yellow-white needles (mp 74-74.5 degrees Celsius).

Workup

  1. temperatureto reflux
  2. temperatureRefluxing
  3. customwas formed in >95 percent yield
  4. washwashed successively with two 150 ml portions of distilled water and 100 ml saturated sodium chloride solution
  5. customThe organic phase was separated
  6. dry with materialdried over sodium sulfate
  7. filtrationfiltered
  8. customSolvents were removed on a rotary evaporator at reduced pressure
  9. dissolutionThe crude 3-bromo-9-(2-chloroethyl)carbazole was dissolved in 230 ml isopropanol
  10. additionwas added
  11. temperatureThe resulting solution was refluxed for 11/2 hours
  12. temperaturerefluxing
  13. custom2 hours
  14. temperatureThe solution was cooled in a freezer during which time a solid residue
  15. customformed
  16. filtrationAfter filtration
  17. washthe solid was washed with water
  18. customRecrystallization from methanol

Sources & evidence

ORD record
ord-97c28156ec2a413b8039a4841fab3553
Source dataset
uspto-grants-1983_08
Patent number
US04396704

Reaction notes

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