Abstract: A new compound, C23H20BrN3OS, containing a quinoline-based iminothiazoline with a thiazoline ring, was synthesized and its crystal and molecular structures were analyzed through single crystal X-ray analysis. The compound belongs to the triclinic system P−1 space group, with dimensions of a=9.2304 (6) Å, b=11.1780 (8) Å, c=11.3006 (6) Å, α=107.146 (5)°, β=93.701 (5)°, γ=110.435 (6)°, Z=2 and V=1025.61 (12) Å3 . The crystal structure showed that C–H···N and C–H···O hydrogen bond linkages, forming infnite double chains along the b-axis direction, and enclosing R2 2 (14) and R2 2 (16) ring motifs. The Hirshfeld surface analysis revealed that H…H (44.1%) and H…C/C… H (15.3%) interactions made the most signifcant contribution. The newly synthesized (Z)-4-bromo-N-(4-butyl-3 (quinolin-3-yl)thiazol-2(3H)- ylidene)benzamide, in comparison to oleanolic acid, exhibited more strong potential against elastase with an inhibition value of 1.21 µM. Additionally, the derivative was evaluated using molecular docking and molecular dynamics simulation studies, which showed that the quinoline based iminothiazoline derivative has the potential to be a novel inhibitor of elastase enzyme. Both theoretical and experimental fndings suggested that this compound could have a number of biological activities.