Ammonium Hydroxide → 6-Hydroxy-2-quinolinepropanoic Acid Ethyl Ester

HRID 328043Notes

Reaction equation

HRID 328043 reaction equation
[CH3:1][C:2]([O:5][C:6](=[O:21])[CH2:7][CH2:8][C:9]1[CH:18]=[CH:17][C:16]2[C:11](=[CH:12][CH:13]=[C:14]([O:19]C)[CH:15]=2)[N:10]=1)(C)C.[OH-].[NH4+]>Br>[CH2:2]([O:5][C:6](=[O:21])[CH2:7][CH2:8][C:9]1[CH:18]=[CH:17][C:16]2[C:11](=[CH:12][CH:13]=[C:14]([OH:19])[CH:15]=2)[N:10]=1)[CH3:1]

Participants

4

Reactant 2

HCID 14923Ammonium HydroxideHCID 541115306-Methoxy-2-quinolinepropanoic Acid 1,1-Dimethylethyl Ester

Product 1

HCID 544101086-Hydroxy-2-quinolinepropanoic Acid Ethyl EsterYield 75.5%

Reagents, catalysts & solvents 1

HCID 260Hydrogen BromideSolvent

Procedure

A mixture of 1.25 g (4.42 mmol) of 6-methoxy-2-quinolinepropanoic acid 1,1-dimethylethyl ester from the preceding example, and 10 mL of 48% hydrobromic acid solution was heated at reflux for 23 hr then poured onto crushed ice. Concentrated ammonium hydroxide solution was added slowly until the solution became neutral at which point it was concentrated to dryness under reduced pressure. To the residue was added 500 mL of ethanol followed by 20 mL of acetyl chloride and the resulting mixture was stirred at reflux for 17 hr. Most of ethanol was removed under reduced pressure, 150 mL of saturated aqueous sodium bicarbonate and 60 mL of water were added, and the mixture was worked-up with ethyl acetate in the usual manner. The crude product was flash chromatographed on 110 g of silica gel, eluting with hexane-ethyl acetate (3:1) to give 0.819 g (75.5%) of the title compound as a white solid, mp 126.5°-127.5° C.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 23 hr
  3. additionthen poured
  4. customonto crushed ice
  5. concentrationwas concentrated to dryness under reduced pressure
  6. additionTo the residue was added 500 mL of ethanol
  7. temperatureat reflux for 17 hr
  8. customMost of ethanol was removed under reduced pressure, 150 mL of saturated aqueous sodium bicarbonate and 60 mL of water
  9. additionwere added
  10. customchromatographed on 110 g of silica gel
  11. washeluting with hexane-ethyl acetate (3:1)

Sources & evidence

ORD record
ord-a9d3bba7da7a4d2383cb697e63c7df35
Source dataset
uspto-grants-1993_12
Patent number
US05273999

Reaction notes

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