One-pot Synthesis of Pyrano[2,3-c]pyrazole Derivatives via Multicomponent Reactions (MCRs) and their Applications in Medicinal Chemistry

Background: Many pyrano[2,3-c]pyrazole derivatives display diverse biological activities and some of them are known as anticancer, analgesic, anticonvulsant, antimicrobial, antiinflammatory, and anti-malarial agents. In recent years, easy convergent, multicomponent reactions (MCRs) have been adopted to make highly functionalizedpyrano[2,3-c]pyrazole derivatives of biological interest. The synthesis of 1,4-dihydropyrano[2,3-c]pyrazole (1,4-DHPP, 2), 2,4- dihydropyrano[2,3-c]pyrazole (2,4-DHPP, 3), 4-hydroxypyrano[2,3-c]pyrazole (4-HPP, 4) derivatives, 1,4,4-substitied pyranopyrazole (SPP, 5) were reported via two-, three-, four- and fivecomponent reactions (MCRs). Methods: This review article compiles the preparation of pyrano[2,3-c]pyrazole derivatives, and it highlights the applications of various pyrano[2,3-c]pyrazole derivatives in medicinal chemistry. Results: Varieties of pyrano[2,3-c]pyrazole derivatives were achieved via “One-pot” multicomponent reactions (MCRs). Different reaction conditions in the presence of a catalyst or without catalysts were adapted to prepare the pyrano[2,3-c]pyrazole derivatives. Conclusion: Biologically active pyrano[2,3-c]pyrazole derivatives were prepared and used in drug discovery research.