Method for preparing quinoline carboxylic acids and derivatives thereof

摘要

A method of preparing substituted and unsubstituted 1,4-dihydro-4-oxo-2 and -3 quinolinic carboxylic acids which comprises heating an ester selected from the group consisting of substituted and unsubstituted anilinomethylenemalonates, anilinofumurates, anilinomaleates and mixutres thereof in the presence of chlorosulfonic acid, oleum and mixtures thereof.