Acetic Acid → 6-methoxyquinoline-2-carboxylic Acid

Participants

Reaction Conditions

Reaction Steps

270 ml of 48% hydrobromic acid are added to a solution of 217 g (0,747 mol) of 1-benzoyl-2-cyano-6-methoxy-1,2-dihydroquinoline in 270 ml of acetic acid, and the mixture is heated at reflux for 30 min. It is filtered and rinsed with diethyl ether, and the solid obtained is then suspended in 2 l of water and heated to 90° C. Aqueous ammonia is then added until the pH=8-9 and the mixture is filtered while hot. The filtrate is acidified at 50° C., by adding acetic acid until the pH=4-5, and is then cooled. The crystallized product is filtered off, rinsed with water and then recrystallized from 250 ml of acetic acid and rinsed with diethyl ether. 129 g of product are obtained.

Provenance & Evidence