Schiff base compounds constructed from pyrazole–acetamide: Synthesis, spectroscopic characterization, crystal structure, DFT, molecular docking and antioxidant activity

Abstract

Two new Schiff base compounds, namely N-(2-((4-(dimethylamino)benzylidene)amino)phenyl)-2-(5-methyl-1H-pyrazol-3-yl)acetamide (DBPA) and N-(2-((4-methoxybenzylidene)amino)phenyl)-2-(5-methyl-1H-pyrazol-3-yl)acetamide (MBPA), have been synthesized through the condensation of N-(2-aminophenyl)-2-(5-methyl-1H-pyrazol-3-yl)acetamide (A) with aromatic aldehydes. Their structures have been elucidated on the basis on spectral data (1H NMR, 13C NMR ESI-MS) and confirmed by a single-crystal X-ray diffraction analysis. Thus, the crystallographic studies showed that the analysis of the crystal packing of DBPA and MBPA revealed 1D and 2D supramolecular architectures, respectively, via various hydrogen bonding interactions. Moreover, the evaluation of compounds A, DBPA and MBPA for their antioxidant activity against DPPH and ABTS radical scavenging assay, and reduction potency assay has been undertaken. using quercetin, Trolox and catechin as standard references respectively. The results obtained showed that DBPA appeared more hydrogen radical donor while MBPA appeared more electron donor. The comparison of the activities of the studied three molecules was carried out using both DFT and molecular docking calculations. Furthermore, ADME/T calculations have been made in order to show that these compounds can be used as potent drugs.