Abstract The synthesis and characterization of a number of 3-aryl-6H-isoxazolo [3, 4-d] pyrazolo [3, 4-b] pyridines and 3-aryl-6H-isoxazolo [5, 4-d] pyrazolo [3, 4–6] pyridines from common precursors, 5-benzoyl-4-chloro-1H-pyrazolo-[3, 4-b] pyridines, has been described. The structures were determined by unambiguous chemical synthesis and by isolation and 13 C nmr analysis of some key, isolated, intermediates. The ability of these compounds to ...