Green Chemistry Approach for Ionic Liquid Extraction and Solvent Free Thiazolidinone Synthesis: Green Synthesis of Thiazolidinones Coupled with Sustainable Areca Husk Extraction

This work presents an integrated green chemistry approach for the sustainable extraction of bioactive constituents from Areca catechu husk and the eco-friendly synthesis of biologically important thiazolidinone derivatives. The study is divided into two major sections. The first part focuses on the valorization of areca husk, an abundant agro-industrial waste, through the extraction of polyphenolic compounds using conventional and advanced extraction techniques. Special emphasis has been placed on the use of the distillable ionic liquid DIMCARB as a green solvent system to improve extraction efficiency while minimizing environmental impact. The extracted materials were further evaluated for total phenolic and tannin contents using Folin–Ciocalteau based analytical methods. Optimization of extraction parameters including solvent polarity, ionic liquid ratio, temperature, and extraction time was systematically investigated to achieve maximum recovery of bioactive compounds. The second part of the research explores the green synthesis of bioactive thiazolidinone derivatives using chitosan as a biodegradable and reusable catalyst. Thiazolidinones are an important class of heterocyclic compounds known for diverse pharmacological activities including anticancer, antimicrobial, anti-inflammatory, and antitubercular properties. The study demonstrates an environmentally benign one-pot synthetic methodology involving aldehydes, amines, and thioglycolic acid under mild reaction conditions. Various reaction parameters such as catalyst loading, solvent systems, reaction temperature, and substrate scope were optimized to improve product yield and reaction efficiency. Advanced analytical and characterization techniques including FT-IR, 1H NMR, GC, and GC-MS were employed for structural confirmation and evaluation of synthesized compounds and extracted constituents. By integrating sustainable extraction processes with green catalytic synthesis, this research highlights the potential of combining natural product chemistry, green solvents, and biodegradable catalysts for pharmaceutical and medicinal chemistry applications. The work contributes toward environmentally responsible