THE catalytic effect of small amounts of pyridine in the reaction between thionyl chloride and carboxylic acids is well known; Carré and Libermann 1 have shown further that it is of great ...

an 18-carbon saturated fatty acid. The normal numbering system, starting with the carboxylic acid, is shown in blue. The carbons and oxygens of the carboxylic acid functional group are red.