Design, Synthesis, Molecular Docking, and In Vitro Antibacterial Evaluation of Benzotriazole-Based β-Amino Alcohols and Their Corresponding 1,3-Oxazolidines

Abstract

In the present study, a series of benzotriazole-based β-amino alcohols were efficiently synthesized in excellent yields via aminolysis of benzotriazolated epoxides under catalyst- and solvent-free conditions. Further these β-amino alcohols were successfully utilized to synthesize the corresponding benzotriazole-based oxazolidine heterocyclic derivatives. All the synthesized compounds were characterized by various spectroscopic techniques such as ¹H NMR, ¹³C NMR, and mass spectroscopy for structure elucidation. The compounds were subjected to a microtiter plate-based antimicrobial assay. The antimicrobial activity results reveal that the compounds 4a, 4e, and 5f were found to be active against Staphylococcus aureus (ATCC-25923) with minimum inhibitory concentrations (MICs) of 32, 8, and 64 μM, respectively. Also, the compounds 4a, 4e, 4k, 4i, 4m, 4n, 4o, 5d, 5e, 5f, 5g, and 5h showed effective activity against Bacillus subtilis (ATCC 6633) with MICs of 64, 16, 16, 16, 64, 16, 64, 64, 32, 64, 8, and 16 μM, respectively. A biological investigation was conducted, including molecular docking of two compounds with several receptors to identify and confirm the best ligand-protein interactions. Hence, this study found a significant strategy to diversify the chemical molecules. The synthesized compounds play a potential role as an antibacterial intensifier against some pathogenic bacteria for the development of antibacterial substances.

Figure 1

Benzotriazole moiety agonists.

Scheme 1. Retrosynthetic Strategy for Benzotriazole Scaffolds

Scheme 2. Preparation of Benzotriazole-Based β-Amino Alcohol and Corresponding 1,3-Oxazolidines

(a) Alcoholic Na₂CO₃, MW, 70/120 °C, 10/25 min; (b) (i) DMSO/K₂CO₃ (1 equiv), rt., (ii) (±)-epichlorohydrin, rt., 2–3 h, 80–90%; (c) neat, rt, few drops of dichloroform in case both reactants are solids; (d) (CH₂O)_n, neat grinding, rt.

Figure 2

2D docking image of 4e docked into the binding site of 6GLA.

Figure 3

2D docking image of 5f docked into the binding site of 4WH9.

Figure 4

HOMO–LUMO with an energy gap.