Synthesis of Some Anilides of 2-Alkyl-4-pyridinecarboxylic Acids and Their Photosynthesis-Inhibiting Activity

Abstract

Homolytic alkylation of 4-pyridinecarbonitrile with radicals generated by silver nitrate catalyzed oxidative decarboxylation of alkanoic acids and subsequent alkaline hydrolysis afforded 2-alkyl-4-pyridinecarboxylic acids 2a-2e. These were converted into the halogeno-hydroxy substituted anilides 3a-3r via acyl chlorides by reaction with the respective aminophenols at 10 °C. Of the compounds tested, 5-chloro-2-hydroxyphenylamide of 2-butyl-4-pyridinecarboxylic acid 3h showed the highest effect upon oxygen evolution rate in spinach chloroplasts system. The structure-photosynthesis-inhibiting activity relationships are briefly discussed.