Structure–activity study leading to identification of a highly active thienopyrimidine based EGFR inhibitor

Based on the thieno[2,3-d]pyrimidine scaffold, a series of new 4-amino-6-aryl thienopyrimidines have been prepared and evaluated as EGFR tyrosine kinase inhibitors. The in vitro activity was found to depend strongly on the substitution pattern in the 6-aryl ring, the stereochemistry, and the basicity at the secondary 4-amino group. A stepwise optimization by combination of active fragments led to the discovery of three structures with EGFR IC50