Synthesis of Pyrano [2,3-c]pyrazole Derivatives via a Multi-Component One-Pot Strategy Using a Cellulose–EDTA–Sodium Alginate-Based Catalyst under Green Conditions

In this study, a novel bio-based heterogeneous catalyst composed of cellulose, EDTA, and sodium alginate was designed and synthesized through a straightforward protocol. In this regards, the catalyst benefits from an interconnected, synergistic network in which cellulose acts as a renewable matrix, EDTA serves as a chelating agent to improve active site accessibility, and sodium alginate contributes biodegradability and structural stability. The resulting composite shows excellent thermal endurance, catalytic recyclability, and green compatibility. Furtheremore, this catalyst was employed in a one-pot multicomponent condensation reaction for the synthesis of pyrano[2,3-c]pyrazole derivatives. The reaction involved aromatic aldehydes, a pyrazole-based amine compound, and either malononitrile or ethyl acetoacetate as the active methylene sources, conducted in ethanol under mild reflux conditions. The protocol demonstrated high efficiency, delivering the desired products in excellent yields with short reaction times and minimal environmental impact. Moreover, the recyclability of the catalyst was confirmed over multiple cycles with negligible loss of activity. Importantly, pyrano[2,3-c]pyrazoles are known for their wide range of pharmacological properties, including antimicrobial, anticancer, anti-inflammatory, and antioxidant effects. This study introduces a sustainable synthetic route that not only advances heterocyclic design but also aligns with green chemistry principles, offering potential for further applications in medicinal and pharmaceutical research.