•The molecular structure of FPDN was determined using X-ray diffraction.•Crystal voids were visualized to understand the crystal packing.•Spectral studies were conducted using IR spectroscopy.•The DFT calculations of the compound were examined.•The DFT theoretical results were compared with the experimental data.•Inhibitory activities for the 11-beta enzyme were shown by the FPDN compound.•Molecular docking analysis was performed in relation to the inhibitory activities of the 11-beta enzyme of FPDN.•The compound is suggested to be a promising drug candidate according to biological evaluation and ADMET predictions. 1-(E)-2-(2-fluorophenyl) diazan-1-ylidene naphthalen-2(1H)-one (FPDN) is an organic compound that belongs to the azo dye family. The structure of the compound was determined using single-crystal X-ray diffraction (XRD). The crystal voids were examined to understand the crystal packing. The antioxidant activity of the molecule was evaluated by DPPH (2, 2-diphenyl-1-picrylhydrazyl) and ABTS 2, 2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) assays. The effective concentration (IC50) indicated that the compound has good antioxidant activity. Additionally, the compound was characterized using Fourier-transform infrared (FT-IR) spectroscopy. Using Density Functional Theory (DFT) calculations, theoretical studies are compared with the experimental results. These studies were found to be in good agreement with the experimental data. The swissTargetPrediction online tool was used to estimate the most probable macromolecular targets of FPDN. The predicted target, 11-beta-hydroxysteroid dehydrogenase 1 (11β-HSD1), was then used for molecular docking studies to examine the potential inhibition of FPDN against this enzyme. Furthermore, the pharmacokinetic and physicochemical features of the FPDN molecule were explored using the SwissADME online tool. Display omitted