Recent Advancements in Microwave Assisted Synthesis of Pyrazole Analogues: An Ecological Synthetic Approach

Pyrazole is among many synthetic compounds' most privileged five-membered nitrogenous structural nuclei. Among a diverse range of heterocyclic analogs, pyrazole derivatives presented remarkable therapeutic significances, including antibacterial, antifungal, antimalarial, antitubercular anti-leishmanial, antidiabetic, antihypertensive and anticancer effects, etc. Pyrazole motif is also available as a structural part of many marketed drugs and clinical trial candidates bearing therapeutic importance. In traditional synthetic methodologies, synthesizing pyrazole derivatives requires several harsh reaction environments, such as introducing organic solvent, longer duration of time, elevated temperature, and energy consumption. By considering the pyrazoles' utility and several drawbacks associated with their traditional synthetic approach, researchers have developed more economical reaction conditions to obtain them. In this regard, microwave irradiation, reaction at room temperature, and solvent and catalyst-free circumstances are ecologically favorable and cost-effective. Microwave-assisted organic synthesis (MAOS) of pyrazole derivatives has exhibited environment-friendly reaction conditions with the minor consumption of hazardous chemicals/solvents and significantly reduced reaction duration. Therefore, this review highlights the microwave-associated synthesis of pyrazole derivatives, likely an excellent alternative to eco-friendly synthetic methodologies.