A structure–activity relationship study for a 2-chloroanilide derivative of pyrazolo [1, 5-a] pyridine revealed that increased EphB3 kinase inhibitory activity could be accomplished by retaining the 2-chloroanilide and introducing a phenyl or small electron donating substituents to the 5-position of the pyrazolo [1, 5-a] pyridine. In addition, replacement of the pyrazolo [1, 5-a] pyridine with imidazo [1, 2-a] pyridine was well tolerated and resulted in ...