EGFR-IN-12 is a 4,6-disubstituted pyrimidine and is a potent, ATP-competitive, irreversible and highly selective EGFR inhibitor with an IC50of 21 nM. EGFR-IN-12 also inhibits mutant EGFRL858R and EGFRL861Q with IC50s of 63 nM and 4 nM, respectively. EGFR-IN-12 displays strong selectivity for EGFR over HER4 (IC50 = 7640 nM) and a panel of 55 other kinases. EGFR-IN-12 induces cells apoptosis and has antitumor activity.