The synthesis and biological evaluation of potent and selective inhibitors of the erbB2 kinase is presented. Based on the 4-anilinoquinazoline chemotype, the syntheses of several new series of erbB2 inhibitors are described with quinazoline and pyrido [4, 3-d] pyrimidine cores. The vast majority of these compounds are found to be> 100× selective over the closely related EGFR kinase. Two lead compounds are further shown to have low ...