Synthesis, X-ray, spectroscopic characterization, DFT and antioxidant activity of 1,2,4-triazolo[1,5-a]pyrimidine derivatives

Two new (4-5) and a known (3) derivatives of 1,2,4-triazolo [1,5-a]pyrimidine are synthesized and characterized through spectroscopic NMR, FT-IR and single crystal X-ray diffraction techniques. Along with experimental data, the predicted spectral data are obtained using density functional theory (DFT) at the B3LYP/6-31 + G (d,p) level of theory. The closest contacts between active atoms of the compounds are identified through Hirshfeld surface analysis and electrostatic potential map (EPM) studies. Relatively, good correlations were found between the experimental and predicted spectroscopic data with correlation coefficients higher than 90%. Hirshfeld surface analysis and EPM reveal that the closest interaction between the units of the compounds are between hydrogen atoms (39.6-46.3%). The antioxidant activity of 3-5 is evaluated using DPPH free radical scavenging and ferric reducing antioxidant power assays. (C) 2018 Elsevier B.V. All rights reserved.