In this study, a new series of 6-amino-1,3-dimethyluracil derivative with 6-(3-substituted N-benzylidene)-1,3-dimethyl pyrimidine-2,4-dione-6-yl derivatives which were synthesized by using one pot synthesis. The reaction of 6-amino-1,3-dimethyluracil and different aromatic aldehyde in ethanol yielded Schiff bases (1-6). In the subsequent step reaction of Schiff bases )1-6) with 2-mercaptoacetic acid, 2-chloroacetic acid and 2-amino acetic acidn in Tetrahydrofuran yielded five membered heterocyclic rings of 6-amino-1,3-dimethyluracil derivative which includes: 2,3-thiazolidin-4-one (7-12), 2,3-oxazolidin-5-one (13-18), 2,3-imidazolidin-4-one (19-24) derivatives. The structures of newly synthesized compounds were confirmed by their physicochemical and spectral means FTIR, 1HNMR and 13CNMR. The synthesized compounds were evaluated in vitro for antioxidant and antimicrobial activities against four types of bacteria and four types of fungi