Hydrochloric Acid → 4-Hydroxy-6,7-dimethoxyquinoline-3-carboxylic acid

HRID 868146Notes

Reaction equation

HRID 868146 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:12]=1[O:13][CH3:14])[NH:9][CH:8]=[C:7]([C:15]([O:17]CC)=[O:16])[C:6]2=[O:20].Cl>[OH-].[Na+]>[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:12]=1[O:13][CH3:14])[NH:9][CH:8]=[C:7]([C:15]([OH:17])=[O:16])[C:6]2=[O:20]

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 100391496,7-Dimethoxy-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid ethyl ester

Product 1

HCID 123690274-Hydroxy-6,7-dimethoxyquinoline-3-carboxylic acidYield 111.7%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

1,4-Dihydro-6,7-dimethoxy-4-oxo-3-quinolinecarboxylic acid, ethyl ester (68.0 g, 0.245 mol) was suspended in 588 ml of 1N sodium hydroxide solution and stirred for 24 hours at 50°-60° C. To the resulting clear solution dilute hydrochloric acid was added at 0° C. The voluminous precipitate was filtered by suction and washed with water. Drying in vacuo furnished 68.2 g of the title acid, melting point 284.4° C.

Workup

  1. filtrationThe voluminous precipitate was filtered by suction
  2. washwashed with water
  3. customDrying in vacuo

Sources & evidence

ORD record
ord-bc8cb26097284d4b912bff31763ffcba
Source dataset
uspto-grants-1988_10
Patent number
US04777252

Reaction notes

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