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

Participants

Reaction Steps

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%).

Provenance & Evidence