635-79-0

15785-08-7

635-79-0

General procedure for the synthesis of 2-methyl-3-quinolinecarboxylic acid from ethyl 2-methylquinoline-3-carboxylate: to a stirred 60% aqueous ethanol solution (80 mL) of potassium hydroxide (4.489 g, 80 mmol) was added ethyl 2-methylquinoline-3-carboxylate (2.153 g, 10 mmol). The reaction mixture was stirred under reflux conditions for 1 hour. Upon completion of the reaction, the ethanol was evaporated under reduced pressure, followed by dilution with the addition of water (10 mL) and acidification with 1 M hydrochloric acid solution to pH < 7. The precipitate precipitated was collected and recrystallized by a solvent mixture of dichloromethane/hexane (1:10, v/v) to give 2-methyl-3-quinolinecarboxylic acid as a yellow solid in 92% yield (1.724 g, 9.2 mmol).