Convenient synthesis of aminopyridinecarboxylic acids

Monoamination of dibromopyridines (I) and (VIII) followed by carbonylation and subsequent hydrolysis of methyl esters (VI) and (X) furnish (alkylamino)pyridinecarboxylic acids (VII) and (XI) in satisfactory to good yields, though the 3,5-dibromopyridine (VIII) reacts more slowly.