The synthesis and investigation of substituent effects in 4-akyl-6-methyl-2-pyridone-3-carboxylic acids

A series od 4-alkyl-6-methyl-2-pyridone-3-carboxylic acids were synthesized by the hydrolysis of corresponding 3-cyanopyridones. Reactivity and IR data were used in a discussion of substituent effects and of inter- and intramolecular hydrogen bonding. A Hammett type correlation of the IR carbonyl stretching frequencies has been performed, using steric and composite steric electronic parameters.