N,N-Dimethylaniline → 4-Bromobenzo[g]quinoline

HRID 650530Notes

Reaction equation

HRID 650530 reaction equation
[N:1]1[C:10]2[C:5](=[CH:6][C:7]3[CH:14]=[CH:13][CH:12]=[CH:11][C:8]=3[CH:9]=2)[C:4](O)=[CH:3][CH:2]=1.CN(C)C1C=CC=CC=1.P(Br)(Br)(Br)(Br)[Br:26]>C(#N)C>[Br:26][C:4]1[C:5]2[C:10](=[CH:9][C:8]3[CH:11]=[CH:12][CH:13]=[CH:14][C:7]=3[CH:6]=2)[N:1]=[CH:2][CH:3]=1

Participants

5

Reactant 3

HCID 949N,N-DimethylanilineHCID 62678Phosphorus pentabromideHCID 178516364HCID 178516364, compound

Product 1

HCID 217125854-Bromobenzo[g]quinolineYield 56.2%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Conditions

Temperature
0 °C

Procedure

Crude benzo[g]quinolin-4-ol (6) (5.07 mmol) was dissolved in 50 mL of acetonitrile (0.1 M) and cooled to 0° C. under a nitrogen atmosphere. N,N-dimethylaniline (3.2 mL, 5 equivalents) was added followed by 3.3 g of phosphorus pentabromide (1.5 equivalents). After removal of the bath, the mixture was heated to reflux and followed by TLC until complete. Upon cooling to rt, the mixture was slowly poured onto ice water and extracted with methylene chloride three times. The organic layers were combined, washed with brine, dried with magnesium sulfate, and concentrated in vacuo. Flash chromatography (gradient: 9:1 to 8:2 to 7:3 hexanes:EtOAc) afforded 736 mg of clean 4-bromobenzo[g]quinoline (7a) in 55% yield for the 2 steps.

Workup

  1. customAfter removal of the bath
  2. temperaturethe mixture was heated
  3. temperatureto reflux
  4. temperatureUpon cooling to rt
  5. additionthe mixture was slowly poured onto ice water
  6. extractionextracted with methylene chloride three times
  7. washwashed with brine
  8. dry with materialdried with magnesium sulfate
  9. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-ff5b371cb25f44d7b953383184ae8a8b
Source dataset
uspto-grants-2001_08
Patent number
US06274596B1

Reaction notes

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