Ethyl 6-methoxy-7-methyl-4-oxo-1,4-dihydro-quinoline-3-carboxylate → 6-Methoxy-7-methyl-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid

Participants

Reaction Steps

Ethyl 6-methoxy-7-methyl-4-oxo-1,4-dihydro-quinoline-3-carboxylate (25.5 g) was suspended in a 2 M aqueous sodium hydroxide solution (250 ml), and the mixture was heated under reflux for 4 hr. The reaction solution was cooled to room temperature, the aqueous layer was then washed with chloroform and was neutralized with dilute hydrochloric acid. The precipitated crystal was collected by filtration and was washed with water, isopropanol, and hexane in that order to give 6-methoxy-7-methyl-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid (22.1 g, yield 98%).

Provenance & Evidence