Synthesis of Fluorine-Containing 2-(1-Aryl-4-oxo-1,4-dihydrocinnolin-3-yl)-2-oxoacetic Acids

Abstract

Acid hydrolysis of ethyl 2-(1-aryl-5,6,7,8-tetrafluoro-4-oxo-1,4-dihydrocinnolin-3-yl)-2-oxoacetates gives 2-(1-aryl-5,6,7,8-tetrafluoro-4-oxo-1,4-dihydrocinnolin-3-yl)-2,2-dihydroxyacetic acids which undergo dehydration on heating in toluene to afford 2-(1-aryl-5,6,7,8-tetrafluoro-4-oxo-1,4-dihydrocinnolin-3-yl)-2-oxoacetic acids. Reactions of the latter with excess morpholine result in replacement of two fluorine atoms in positions 5 and 7 by the amine residues.