Sodium Hydroxide → 2-Oxo-1,2,3,4-tetrahydroquinoline-5-carboxylic acid

Participants

Reaction Steps

2 Grams of 5-carboxycarbostyril was suspended in 30 ml of water, then 10N-sodium hydroxide aqueous solution was added to dissolve the crystals. To this solution was added 500 mg of 10% platinum-carbon and this mixture was catalytically reduced with hydrogen gas under condition of 3-4 kg/cm2 at 70° C. After the completion of the reaction, the catalyst was removed from the reaction mixture by filtration, then the pH of the filtrate was adjusted to about pH=1 by adding concentrated hydrochloric acid. The precipitated crystals were collected by filtration, recrystallized from methanol to obtain 820 mg of 5-carboxy-3,4-dihydrocarbostyril in the form of colorless needle-like crystals.

Provenance & Evidence