Hydrochloric Acid → 6-Methoxy-2-methylquinoline-3,4-dicarboxylic acid

Participants

Reaction Steps

A solution of 59.4 g (0.335 mole) of 5-methoxyisatin, 225 g KOH in 800 ml H2O was treated dropwise with 121.4 g (0.932 mole) of ethylacetoacetate at 55° over a 2 hour period. The solution was refluxed 45 minutes and stirred 2 days at room temperature. Acidification with 300 ml concd. HCl while maintaining the temperature at ambient conditions gave a tan solid that was filtered, washed with H2O and dried; yield 60.8 g (69.4% ).

Provenance & Evidence