Green synthesis, structural characterization, BSA binding and NLO properties of newly synthesized pyrazol-chromeno[2,3-d]pyrimidine derivative: An experimental and theoretical studies

A new pyrazol-chromeno[2,3-d]pyrimidine compound, 7-bromo-5-(5-hydroxy-3-methyl-1H-pyrazol-4-yl)-1,5-dihydro-2H-chromeno[2,3-d]pyrimidine-2,4(3H)-dione (Br-PCP) was obtained in the three-component reaction of pyrazolone, 5-bromosalicylaldehyde, and barbituric acid. The reaction was performed in the presence of tartaric acid, using a refluxed mixture of water: ethanol (4:1v/v) for 3 h Br-PCP was obtained in very good yield (75 %), and characterized by elemental analysis, IR, NMR, and UV-Vis spectroscopy, as well as by a single crystal X-ray diffraction study. Additionally, theoretical calculations were used to support and to reinforce experimentally obtained analytical data (IR, H-1 NMR, C-13 NMR, and UV-Vis). The interaction of Br-PCP with bovine serum albumin (BSA) has been investigated using temperature-dependent fluorescence and molecular docking study. The obtained binding constant indicates the moderate type of association of ligand to protein, and thermodynamic parameters show that the binding process is spontaneous and occurs via van der Waals and hydrogen bonding interactions. Molecular docking results explain the connecting of BSA to the ligand and it is consistent with the experimentally obtained results. Also in this study, the dipole moment, polarizability, and first order hyperpolarizability were calculated in order to determine the nonlinear optical (NLO) activity of the title molecule. First order hyperpolarizability results validated the molecule's nonlinear optical activity.