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

HRID 989055Notes

Reaction equation

HRID 989055 reaction equation
C([O:3][C:4]([C:6]1[CH:7]=[N:8][C:9]2[C:14]([C:15]=1[Cl:16])=[CH:13][C:12]([O:17][CH3:18])=[C:11]([O:19][CH3:20])[CH:10]=2)=[O:5])C.[OH-].[Na+].Cl>C(O)C.O>[Cl:16][C:15]1[C:14]2[C:9](=[CH:10][C:11]([O:19][CH3:20])=[C:12]([O:17][CH3:18])[CH:13]=2)[N:8]=[CH:7][C:6]=1[C:4]([OH:5])=[O:3]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 103571783-Carbethoxy-4-chloro-6,7-dimethoxylquinoline

Product 1

HCID 180050224-Chloro-6,7-dimethoxyquinoline-3-carboxylic acidYield 116.4%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

4-chloro-6,7-dimethoxy-3-quinolinecarboxylic ethyl ester (ex RSL) (50 g) was suspended in ethanol (400 ml) and aqueous 2M sodium hydroxide (400 ml) was added with stirring, stirred for 24 hours. The reaction mixture was diluted with water (400 ml), cooled in an ice/water bath and brought to pH4 by carefully addition of concentrated hydrochloric acid. The resulting solid was filtered off, washed with water and dried in a vacuum oven at 50° C. To give 4-chloro-6,7-dimethoxy-3-quinolinecarboxylic acid (52.7 g, 98.7%).

Workup

  1. stirringstirred for 24 hours
  2. temperaturecooled in an ice/water bath
  3. filtrationThe resulting solid was filtered off
  4. washwashed with water
  5. customdried in a vacuum oven at 50° C

Sources & evidence

ORD record
ord-88e97d518c1b403e8554a7da5a29042a
Source dataset
uspto-grants-2003_10
Patent number
US06638945B1

Reaction notes

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