In this article 4-(((4-ethyl-5-(thiophene-2-yl)-4H-1,2,4-triazol-3-yl)thio)methyl)-6-methoxycoumarin compound (ETMM) has been synthesized and characterized both experimentally and theoretically. The synthesized compound was characterized experimentally by Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR) and Ultraviolet (UV) spectroscopic techniques. It was used Gaussian 09 software for theoretical calculations. Based on the theoretical data obtained was calculated the global reactivity descriptor of ETMM. Density Functional Theory (DFT) calculations of molecular electrostatic potentials and frontier molecular orbitals of ETMM were implemented at the B3LYP/6-311G(d,p) level of theory. It was observed that there was an excellent agreement between experimental NMR and calculated NMR data. R2 for 1HNMR and 13CNMR were computed as 0.992 and 0.993, respectively.