2-(5-Arylfurfurylidene/5-nitrofurfurylidene)-5-aryl-7-(2,4-dichloro-5-fluoro phenyl)-5H-thiazolo[2,3-b]-pyrimidin-2(1H)-ones 5 and 6 are synthesized by a novel three component reaction of 4,6-diarylpyrimidino-2(1H)-thiones 4, monochloroacetic acid, arylfurfuraldehydes and 5-nitro-2-furfuraldenediacetate, respectively. The newly synthesized compounds are characterized by elemental analysis, IR, 1 H NMR and mass spectral studies. These compounds exhibited in vitro antitumour activity with moderate to excellent growth inhibition against a panel of 60 cell lines of leukemia, non-small cell lung cancer melanoma, ovarian cancer, prostate cancer and breast cancer.