Novel Multi-Component Synthesis of Pyranopyrazoles from Pyrazolones, Phenylacetylene, and Aldehydes

Multi-component reactions (MCRs) have emerged as a powerful tool for the construction of novel and complexmolecular structures due to their advantages over the conventional multi-step synthesis.The major advantagesof MCRs include lower costs, shorter reaction times, high atom-economy, and energy savings by avoiding thetime-consuming and expensive purification processes [1]. Pyranopyrazoles are an interesting class of heterocyclic compounds. They have been used as fungicidal, bactericidal,and anti-cancer agents. They have also been reported as pharmaceutical ingredients and biodegradable agrochemicals [2]. In this paper, novel multi-component syntheses of pyranopyrazoles from pyrazolones, phenyl acetylene, and aldehydes in the presence of TFA/HOAcarereported. The structures of the products obtainedwere determined by the1H NMR, 13C NMR, FT-IR, and mass spectroscopic techniques. After determining the optimumreaction conditions, new pyranopyrazolederivatives were synthesized.