Ethyl 4,5-dihydroxyquinoline-3-carboxylate → 4,5-Dihydroxyquinoline-3-carboxylic acid

HRID 469942Notes

Reaction equation

HRID 469942 reaction equation
C([O:3][C:4]([C:6]1[C:15](=[O:16])[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][C:13]=2[OH:17])[NH:8][CH:7]=1)=[O:5])C>[OH-].[Na+]>[OH:17][C:13]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:14]=1[C:15](=[O:16])[C:6]([C:4]([OH:5])=[O:3])=[CH:7][NH:8]2

Participants

3

Reactant 1

HCID 12956450Ethyl 4,5-dihydroxyquinoline-3-carboxylate

Product 1

HCID 152291404,5-Dihydroxyquinoline-3-carboxylic acidYield 87.7%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

A mixture of 5-hydroxy-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid ethyl ester (700 mg, 3 mmol) in 10% NaOH (20 ml) was heated at reflux overnight. After cooling, the mixture was extracted with ether. The aqueous phase was separated and acidified with conc. HCl to pH 1-2. The resulting precipitate was collected via filtration to give 5-hydroxy-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid (A-3) (540 mg, 87%). 1H NMR (DMSO-d6) δ 13.7 (br, 1 H), 13.5 (br, 1 H), 12.6 (s, 1 H), 8.82 (s, 1 H), 7.68 (t, J=8.1 Hz, 1 H), 7.18 (d, J=8.4 Hz, 1 H), 6.82 (d, J=8.4 Hz, 1 H); ESI-MS 205.9 m/z (MH+).

Workup

  1. temperaturewas heated
  2. temperatureat reflux overnight
  3. temperatureAfter cooling
  4. extractionthe mixture was extracted with ether
  5. customThe aqueous phase was separated
  6. filtrationThe resulting precipitate was collected via filtration

Sources & evidence

ORD record
ord-29d8cc0ab4bc4f1198cf2ee0bf3266a2
Source dataset
uspto-grants-2014_01
Patent number
US08629162B2

Reaction notes

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