An efficient green approach for the synthesis of benzothiazole‐linked pyranopyrazoles as promising pharmacological agents and docking studies

Abstract

Benzothiazole‐tethered pyranopyrazoles derivatives were prepared via environmentally favorable conditions, which included eco‐friendly catalyst, ethanol−water solvent, one‐pot reaction, and atom‐ and step‐economy procedures. Excellent yield of the products was observed. Besides, all products were screened for their antimicrobial behavior. From the biological results, it was seen that most of the compounds possessed high to moderate antimicrobial properties. Compound 6a gave prominent antimicrobial property followed by 6d, 6l, and 6n. In addition, computer‐aided studies of the active compounds were also conducted. In this, selected compounds were docked into the intercalation site of DNA of the DNA−gyrase complex. From these results, the highest binding energy of −10.1 kcal/mol was for 6a against DNA−gyrase. This is the first eco‐friendly synthetic method for the preparation of benzothiazole‐pyranopyrazoles and the synthetic effort in this study may serve as a model for additional environmentally benign reactions. The biological results may prompt further studies related to antibiotic drugs.

Recent Synthesis of Mono‐ & Bis‐Pyranopyrazole Derivatives

“…Pyranopyrazole‐benzothiazole and oxadiazole compounds ( 23 & 24 ) were synthesized by one‐pot methodology to achieve 81–91 % yield of products. Compound ( 23 ) with methyl‐substituted gave excellent antimicrobial properties followed by methoxy and hydroxy‐substituted compounds also showed better activities against S. aureus, B. subtilis, P. vulgaris, E. coli, A. niger and A. flavus [178,179] . Moreover compound ( 24 ) exhibited antioxidant activities, EDG compounds ( 24 ) at para position confirmed higher antioxidant activity as compared to ortho ‐substituted compounds [180] .…”

Copper‐Decorated Magnetite Polydopamine Composite (Fe3O4@PDA): An Effective and Durable Heterogeneous Catalyst for Pyranopyrazole Synthesis

“…Considering the benefits of MCRs, catalytic approaches to the multicomponent synthesis of pyranopyrazoles have provided best routes to the straightforward synthesis of these scaffolds. Recently, various catalytic such as mesoporous silica nanoparticles, [12] metal Schiff‐base complexes, [13,14] Montmorillonite K10 clay, [3,15] ionic liquids or copper immobilized ionic liquid, [16,17] and heterogeneous nanocatalysts [18–20] have been reported for the one‐pot multicomponent synthesis of pyranopyrazoles. Also, the synthesis of pyranopyrazoles using starch@Fe 3 O 4 biocatalyst in water and magnetic Biochar/Fe 3 O 4 ‐TiO 2 nanoparticles has been done in recent years [21,22] .…”