Exploitation of pyrazole C-3/5 carbaldehydes towards the development of therapeutically valuable scaffolds: a review

Over the past decades, pyrazole has displayed significant importance in various areas of chemistry and industry owing to its unique nature, reactivity, and properties. Pyrazole is a versatile compound with a wide range of applications in pharmaceuticals, agriculture, materials science, and various branches of science. Specifically, pyrazole C-3/C-5 carbaldehydes can be used as a building block in organic synthesis to create more valuable and bioactive molecules. In this context, pyrazole C-3/C-5 carbaldehydes may be explored for achieving pyrazole fused/linked heterocyclic skeletons by employing different organic transformations. The investigation of pyrazole C-3/C-5 carbaldehydes has resulted in the formation of a range of biologically potent heterocyclic structures, which include pyrazole C-3/C-5-based silicon derivatives, pyrazole C-3/C-5-based Schiff base derivatives, pyrazole C-3/C-5-based metal complexes, pyrazole C-3/C-5-based imidazo[1,2-a]azines, pyrazole C-3/C-5-based sulphur containing derivatives, and pyrazole C-3/C-5-based thioamide and amides, as well as other pyrazole fused/tethered polycyclic systems. Previous reports have shown that derivatives synthesized from the pyrazole C-3/C-5 carbaldehyde have demonstrated favorable biological uses like 5-HT3A receptor antagonists, allosteric inhibitors, insecticidal activity, antioxidant, antifungal, antiproliferative and antimicrobial. Pyrazole C-3/C-5 carbaldehydes have the potential to be highly utilized in the medical field as well as material science if studied judiciously. This review focuses on the exploration of pyrazole C-3/C-5 carbaldehydes towards the synthesis of highly diversified pyrazole-based molecular hybrids till 2023 and describes their promising utilization in the field of pharmaceutical science.