© 2020, King Fahd University of Petroleum & Minerals.An azo molecule, 2,2-dimethyl-5-(m-tolyldiazenyl)-1,3-dioxane-4,6-dione (DTDD), was designed, synthesized and evaluated for its antibacterial potential. The structure of the DTDD was confirmed by 1H-NMR, 13C-NMR, FT-IR and UV–Vis spectra. The molecular geometry and vibrational frequency calculations of the DTDD in the ground state were performed by the density functional theory (DFT) employing the B3LYP level with the 6-311G(d,p) basis set. 1H-NMR and 13C-NMR chemical shifts were calculated by using the gauge independent atomic orbital (GIAO) method. Electronic property and HOMO–LUMO calculations were carried out by a time-dependent DFT (TD-DFT) approach. The calculated spectroscopic values for the DTDD were in very good agreement with experimental ones. Besides, in vitro antibacterial activity of the DTDD was studied against five different bacterial cultures. DTDD showed antibacterial activity with an MIC range of 62.5–500 µg/mL. The best antibacterial activity was found with 62.5 µg/mL against S. aureus. Additionally, molecular docking studies against β-ketoacyl-acyl carrier protein synthase III (KAS III) and lipoteichoic acid synthase (LtaS) were performed. According to the binding energy (− 7.67 kcal/mol) and full fitness score (− 2391.78), the ligand had a better orientation with LtaS. Druglikeness and ADME parameters were also calculated and the TPSA value was found to be 76.99 Å2. The calculated values showed that DTDD had good oral drug candidate properties.