X series of Pfitzinger condensations, utilizing n-alkyl methyl ketones (alkyl= methyl through hexyl), has been accoinplished. The unsymmetrical ketones produce two isomeric cinchoninic acids, a 2-monosubstituted acid and a 2,: j-disubstituted acid, the monosubstituted compound usually being formed in the larger amount. A new sequence of syntheses has been developed in order to establish the structure of one series of these ...
