Conformational and the isomeric analysis of pyridinecarboxylic acid amides

The potential energy profile calculations by quantum mechanic semi-empirical methods AM1 and PM3 for three types of the pyridinecarboxylic acids amides are carried out. It is shown that the potential energy surfaces of pyridine-3-carboxylic and pyridine-4-carboxylic acids have two global minimums and are almost identical while the pyridine-2-carboxylic acid amide potential energy surface has only one broad minimum.