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

HRID 73902Notes

Reaction equation

HRID 73902 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, 1H), 13.5 (br, 1H), 12.6 (s, 1H), 8.82 (s, 1H), 7.68 (t, J=8.1 Hz, 1H), 7.18 (d, J=8.4 Hz, 1H), 6.82 (d, J=8.4 Hz, 1H); 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-41fdcdbf79634d30b9961457c09af4fb
Source dataset
uspto-grants-2014_09
Patent number
US08829204B2

Reaction notes

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