Hydrochloric Acid → 2,4-Dimethylquinolin-8-ol

HRID 2384517Notes

Reaction equation

HRID 2384517 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[OH:8].Cl.[CH3:10][C:11](=O)[CH:12]=[CH:13][CH3:14].[OH-].[Na+]>C(OCC)(=O)C>[CH3:10][C:11]1[CH:12]=[C:13]([CH3:14])[C:7]2[C:2](=[C:3]([OH:8])[CH:4]=[CH:5][CH:6]=2)[N:1]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 58012-AminophenolHCID 12248PentenoneHCID 14798Sodium Hydroxide

Product 1

HCID 206416412,4-Dimethylquinolin-8-olYield 36.1%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

In a three-necked flask were placed 33 g of o-aminophenol and 207 g of concentrated hydrochloric acid and the mixture was heated to the reflux temperature and stirred for 1 hour. To the mixture being heated under reflux was slowly added 51 g of 3-penten-2-one with a purity of 65% over 2 hours and stirring was continued for another 2 hours. Upon completion of the reaction, the reaction mixture was cooled to room temperature, 300 ml of a 48% aqueous solution of NaOH was added until the aqueous phase became alkaline. Ethyl acetate was added further, the organic layer was recovered and the solvent was distilled off under reduced pressure. The crude product thus obtained was purified by gas chromatography, recrystallized from hexane and the crystals collected by filtration were washed with hexane and dried at 80° C. under reduced pressure to give 18.9 g of 2,4-dimethyl-8-quinolinol.

Workup

  1. customIn a three-necked flask were placed
  2. temperatureTo the mixture being heated
  3. temperatureunder reflux
  4. customover 2 hours
  5. stirringstirring
  6. waitwas continued for another 2 hours
  7. customUpon completion of the reaction
  8. customthe organic layer was recovered
  9. distillationthe solvent was distilled off under reduced pressure
  10. customThe crude product thus obtained
  11. customwas purified by gas chromatography
  12. customrecrystallized from hexane
  13. filtrationthe crystals collected by filtration
  14. washwere washed with hexane
  15. customdried at 80° C. under reduced pressure

Sources & evidence

ORD record
ord-8d2058bba76445a985888607fbdf5131
Source dataset
uspto-grants-2012_09
Patent number
US08263770B2

Reaction notes

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