Abstract - The chemical structure of the newly synthesized compound Ethyl-6-methyl-2-oxo-4- (3,4,5-trichlorophenyl)-1,2,3,4-tetrahydropyrimidine-5-carboxylate 4 was confirmed by elemental analysis, 1H NMR, 13C NMR, and ESI-HRMS spectral data. In addition, in the form of the complete and partial density of states, the HOMO-LUMO energy gap, and electrostatic potential map, etc., some quantum chemical insights have been obtained. Furthermore, to demonstrate the possible applications of dihydropyrimidinone 4 in nonlinear optics, the polarizability and first hyperpolarizability were measured. Molecular docking is also determined in order to illustrate the over expression of estrogen receptor in 92 % of 2J9M protein. The antitumor activity of these compound was evaluated on breast cancer (MCF-7) cell lines by a cell viability assay utilizing the tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT). Although with varying degrees, a significant growth inhibitory and cytotoxic effect was observed on MCF-7 cancer cell line. The tested compound 4, was active against MCF-7 cell line (in-vitro analysis) with IC50 values of 45 μM. The compound was subjected for the DPPH & ABTS tests, evaluated its antioxidant activity. With further characterization, mechanism of biological action, this compound 4 shall be a potential / useful candidate as anticancer drug.