Abstract A series of thieno [2, 3-d] pyrimidines and furo [2, 3-d] pyrimidines were synthesized and evaluated for the c-Met inhibition. Thieno [2, 3-d] pyrimidine 6b stood out as the most potent showing an IC 50 of 35.7 nM. This compound displayed high inhibitory effect on cell proliferation in BaF3-TPR-Met cells and showed high selectivity for c-Met family against other 14 tested kinases. However, compound 6b was found ineffective in the c-Met- ...