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

HRID 423729Notes

Reaction equation

HRID 423729 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-5674e1bb54bf48cf8e33fe0cb4c61c61
Source dataset
uspto-grants-2012_01
Patent number
US08101767B2

Reaction notes

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