The density (ρ), viscosity (η) and ultrasonic velocity (U) of pure solvents (chloroform (CF), N,N-dimethyl formamide (DMF)) and solutions of 2-((4-acetyl-5-(2-hydroxyphenyl)-5-methyl-4,5-dihydro-1,3,4-oxadiazol-2-yl)methylthio)-3-o-tolylquinazolin-4(3H)-one (PDI-C) (0.001, 0.002, 0.004, 0.006, 0.008, and 0.010 mol dm−3) in CF and DMF are investigated at 303, 308 and 313 K at atmospheric pressure. Various thermodynamic parameters such as acoustical impedance (Z), adiabatic compressibility (κa), inter molecular free path length (Lf), Rao's molar sound function (Rm), Van der Waals constant (b), internal pressure (π), relaxation time (τ), free volume (Vf) and solvation number (Sn) are calculated by using ρ, η and U data. The results obtained are interpreted in terms of solute–solvent and solute–solute interactions. The structure making or structure-breaking abilities of the solute in CF and DMF solvent are also studied.