Conversion of the carboxyl group to the corresponding trichloromethyl group in the quinoline series

Abstract

AbstractVarious substituted quinaldinic acids were treated with phosphorus pentachloride in an excess of thionyl chloride. Carboxyl groups of quinaldinic acid, 6‐methyl‐, 6‐chloro‐, 4‐phenyl‐ and 4‐(p‐chlorophenyl)quinaldinic acids and benzo[f]quinoline‐3‐carboxylic acid were converted to the trichloromethyl group, while those of 8‐methyl‐, 4‐(3,4‐dichlorophenyl)‐, 4‐(p‐nitrophenyl)‐quinaldinic acids and benzo[h]quinoline‐2‐carboxylic acid were not. The difference is discussed on the basis of the effects of the basicity of ring nitrogen and steric factors.