6-methoxyquinoline-2-carboxylic Acid → 6-Hydroxyquinoline-2-carboxylic acid

HRID 1462917Notes

Reaction equation

HRID 1462917 reaction equation
C[O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[N:9]=[C:8]([C:13]([OH:15])=[O:14])[CH:7]=[CH:6]2>Br>[OH:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[N:9]=[C:8]([C:13]([OH:15])=[O:14])[CH:7]=[CH:6]2

Participants

3

Reactant 1

HCID 111832986-methoxyquinoline-2-carboxylic Acid

Product 1

HCID 133367806-Hydroxyquinoline-2-carboxylic acid

Reagents, catalysts & solvents 1

HCID 260Hydrogen BromideSolvent

Procedure

6-Methoxy-2-quinolinecarboxylic acid (80.6 g) was refluxed in 48% hydrobromic acid (450 ml) for twenty-four hours. After cooling to room temperature, the solid was collected by filtration and then dissolved in water (1300 ml) at 90° and the pH of this solution was adjusted to 8-9 with concentrated ammonium hydroxide. After cooling to room temperature, the pH of this solution was adjusted to 4-5 with acetic acid. The resulting 6-hydroxy-2-quinolinecarboxylic acid was collected by filtration and washed with water (400 ml); yield 70 g, m.p. 260°-261° (dec).

Workup

  1. filtrationthe solid was collected by filtration
  2. dissolutiondissolved in water (1300 ml) at 90°
  3. temperatureAfter cooling to room temperature
  4. filtrationThe resulting 6-hydroxy-2-quinolinecarboxylic acid was collected by filtration
  5. washwashed with water (400 ml)

Sources & evidence

ORD record
ord-cfc72d50ee1f4a3fab94b2fb4445f645
Source dataset
uspto-grants-1984_07
Patent number
US04461896

Reaction notes

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