Structural study and vibrational spectra of 3-amino-2-(4-chlorophenyl) quinazolin-4(3H)-one

► 3-Amino-2-(4-chlorophenyl) quinazolin-4(3H)-one was studied by using B3LYP level. ► A complete assignment of the observed spectral features is proposed. ► A set of scaled force constants were obtained by using B3LYP calculations. ► The nature of the three rings was studied by NBO and AIM analysis. ► The frontier molecular HOMO and LUMO orbitals for the compound were analyzed.