Acid-catalyzed condensation of 2-amino-3-mercapto-6-methylpyridine and 3-amino-pyridine- 2 [1H]-thiones with 4-chloropyrimidines having free 5-carbon centers gave N-(3-mercapto-2- pyridyl)-6-pyrimidinylamines and N-(2-thioxo-3-pyridyl)-6-pyrimidinyl-amines, which we