Amides of Aromatic Carboxylic Acids

Pyridine-4-thiocarboxamide is reduced in two, two-electron steps in acidic medium at the potential of the second wave, reduction gives 4-aminomethylpyridine. The product of reduction at the first wave is believed to be the aminothiol [126]. These three cases show that the preparative outcome of an amide reduction is strongly dependent on the substituents at the amide group and that the changes manifest themselves in the chemical step [Eq. (32)]. For the amides of aromatic carboxylic acids, the reduction potential may be gleaned from a comprehensive compilation [127]. 

Substituted amides of aromatic carboxylic acids or of sulfonic acids are prepared by the Schotten-Baumann technique the acid chloride is added to the amine in the presence of a base, either aqueous sodium hydroxide or pyridine. For example ... 

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