In the present work, 1-(5-methyl-2-phenyl-1H-imidazol-4-yl)ethanone 1 was prepared and used as a precursor for the synthesis of new thiazole, arylidiene and coumarin derivatives. The antimicrobial, antioxidant, anti-hemolytic, and cytotoxic activities of new compounds have been screened. Compound 12 showed an excellent antibacterial activity for all the tested bacteria with minimal inhibitory concentration (MIC) ranged between 21.9 and 43.8 μg/mL. While, compounds 2, 8 and 10a were the best antioxidant reagents using the DPPH method. Compounds 6a and 10b proved to exhibit potent antioxidative activity as reflected in the ability to inhibit lipid per-oxidation in rat brain and kidney homogenates and rate erythrocyte hemolysis. Compounds 6a proved to have the highest cytotoxic activity (81.9%) followed by 2, 6c, 7b and 12 using in vitro Ehrlich ascites assay. The details synthetic methods, spectroscopic data and biological results are recorded.