Explorations on the electronic structure and spectroscopic IR assignments of 5-methyl-2-(2-oxopropyl)-pyrazolo[5,1-b]quinazolin-9(3H)-one molecule

In the present work, theoretical investigations on a quinazoline derivate, 5-methyl-2-(2-oxopropyl)pyrazolo[5,1-b]quinazolin-9(3H)-one, have been carried out through quantum mechanical density functional B3LYP/6-31G(d,p) method to explore its electronic structure and vibrational features. The normal modes analysis was executed to predict the contributions of different vibrational modes at the required frequencies in the infrared region and the spectral peaks have been assigned accordingly. Besides, certain electronic properties that are associated with chemical reactivity like, HOMO-LUMO energy gap, molecular electrostatic potential, Mulliken partial charges, etc have been estimated and discussed herein. It has been established that the molecule is chemically reactive and may be used in designing drugs as COX-2/5-LOX inhibitor.