Efficient microwave-assisted chemical processes were applied to the synthesis of an array of novel N-(4-methoxyphenylamino)-2-methyl benzo- pyrido- or pyrazinothieno[3,2-d]pyrimidin-4-amine derivatives. These heteroaromatic systems were envisioned as potent bioisosteric analogues of MPC-6827 (also called Azixa or Verubulin), an anticancer agent previously developed until phase II clinical studies. A brief evaluation and comparison of their antiproliferative activity on HT-29 and Caco-2, two human colorectal cancer cell lines, are also reported. At the tested concentrations (5 and 10 µM), two thieno[3,2-d]pyrimidin-4-amines exhibit similar inhibitory effect to MPC-6827 on human colorectal cancer cell proliferation.