Carbazole → N-(3-Bromopropyl)carbazole

HRID 1952420Notes

Reaction equation

HRID 1952420 reaction equation
[CH:1]1[C:13]2[NH:12][C:11]3[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=3)[C:5]=2[CH:4]=[CH:3][CH:2]=1.[Br:14][CH2:15][CH2:16][CH2:17]Br.[H-].[Na+]>C1COCC1.O.C(O)C>[Br:14][CH2:15][CH2:16][CH2:17][N:12]1[C:11]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=2[C:5]2[C:13]1=[CH:1][CH:2]=[CH:3][CH:4]=2

Participants

7

Reactant 3

HCID 6854CarbazoleHCID 80011,3-DibromopropaneHCID 24758Sodium hydride

Product 1

HCID 10732069N-(3-Bromopropyl)carbazoleYield 30%

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
78 °C

Procedure

Carbazole (15.00 g, 89.71 mmol) and 1,3-dibromopropane (45.5 mL, 450 mmol) were dissolved in ˜200 mL dry THF and stirred under argon in a 500 mL rbf. Sodium hydride (3.23 g, 134.56 mmol) was added and the mixture was brought to reflux (˜78° C.) and allowed to do so for 40 hours. After cooling the mixture was diluted in ˜800 mL water and extracted with ethyl acetate. The organic layer was dried over magnesium sulfate and concentrated by rotary evaporation to leave an orange oil and light brown solid. This was distilled under high vacuum (0.05 Torr) at 100° C. for 2 hours to remove excess dibromo compound. A tlc in 30:1 hexanes:ethyl acetate showed 6 spots. A column was run in 30:1 hexanes:ethyl acetate and the third spot was isolated as a thick yellow oil. This oil was dissolved in hot ethanol and put in the −20° C. freezer overnight to yield a white solid (7.70 g, 30% yield). This compound is reported in the literature and the 1H NMR is consistent with the structure.

Workup

  1. temperatureAfter cooling the mixture
  2. extractionextracted with ethyl acetate
  3. dry with materialThe organic layer was dried over magnesium sulfate
  4. concentrationconcentrated by rotary evaporation
  5. customto leave an orange oil and light brown solid
  6. distillationThis was distilled under high vacuum (0.05 Torr) at 100° C. for 2 hours
  7. customto remove excess dibromo compound
  8. customethyl acetate and the third spot was isolated as a thick yellow oil
  9. customput in the −20° C. freezer overnight

Sources & evidence

ORD record
ord-5281431c2fa64b87bd5a20bce55f2f96
Source dataset
uspto-grants-2013_03
Patent number
US08405069B2

Reaction notes

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