A combined experimental and theoretical study of alkyl 2-(3-benzoyl-4‑hydroxy-1,1-dioxido-2H-benzo[e][1,2]thiazin-2-yl)acetates: Synthesis, X-ray crystallography and DFT

Abstract

Benzothiazine derivatives belongs to an important class of organic compounds with a wide range of application in the field of biotechnology and medicinal chemistry, and many of its derivatives have been considered in drug discovery. A series of three alkyl 2-(3-benzoyl-4‑hydroxy-1,1-dioxido-2H-benzo[e][1,2]thiazin-2-yl)acetates (3a–c) were synthesized from the sulfonimidamides through multistep reactions. The molecular geometry of these compounds has been investigated with the help of X-ray crystallography and quantum mechanical calculations. The molecular structural optimization and structural properties were calculated using the Density Functional Theory method and B3LYP hybrid functional with 6–311+G* basis set. Non-covalent interactions studies, energetics and reactivity properties of 3a-c compounds have been explored through local and global reactivity descriptors, UV-Visible spectral analysis and molecular electrostatic potential illustrations. It is found that the compound 3b is more reactive than others because of its lowest frontier molecular orbital energy gap (ΔE=3.46 eV) and low chemical hardness (η=0.23eV) than others. Furthermore, the investigations of Non-linear optical properties and thermodynamic parameters have also been carried out which shows that these compounds can be used as a non-linear optical material in the field of telecommunication and information technologies.