Synthesis of novel pyrazole‐based triazolidin‐3‐one derivatives by using ZnO/ZrO₂ as a reusable catalyst under green conditions

Abstract

An efficient approach for the synthesis of 10 novel pyrazole‐based 1,2,4‐triazolidin‐3‐one derivatives catalyzed by ZnO‐loaded ZrO2 as heterogeneous catalyst with ethanol as solvent is described. The structure of the mixed metal oxide catalyst was characterized by various instrumental techniques (scanning electron microscopy, transmission electron microscopy, X‐ray diffraction and Brunauer–Emmett–Teller). In smooth reactions, products were accomplished in excellent yields (90–94%) with short reaction times (≈ 45 min). ZnO/ZrO2 catalyst exhibited good recyclability. The catalyst is reused six times without any noticeable loss of activity. The major advantages of this method are operational simplicity, mild conditions, simple work‐up procedure and broad functional group tolerance.

Advances in Pyranopyrazole Scaffolds’ Syntheses Using Sustainable Catalysts—A Review

“…Low catalyst-loading, eco-friendly conditions, a broad substrate scope, a simple workup and the use of a water medium were the advantages of this procedure. Borhade et al [64] designed a ZnS nanoparticle catalyst by hydrothermal method for synthesising pyrano[2,3-c]-pyrazoles (23). P-XRD, TEM, SEM and BET microscopic spectroscopic analysis validated the structure of the subsequent ZnS nanoparticles.…”

“…On the other hand, multicomponent reactions (MCRs) have steadily gained significance in synthetic organic chemistry [ 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. MCRs offer many benefits—e.g., greater yields, high atom efficiency, reduced reaction time, high convergence, minimisation of purification requirements and waste generation—compared to multiple-step syntheses [ 20 , 21 , 22 , 23 , 24 , 25 ]. Typically, multi-step procedures require the purification of reaction products in each step and demand appropriate solvents and reagents.…”

Green synthesis and characterisation of novel [1,3,4]thiadiazolo/benzo[4,5]thiazolo[3,2-a]pyrimidines via multicomponent reaction using vanadium oxide loaded on fluorapatite as a robust and sustainable catalyst

“…Though more vanadium is present in 5% V 2 O 5 /FAp, the inferior activity could be due to higher agglomeration of the vanadia particles on the surface of uorapatite. 46 With agglomeration, the vanadium oxide particles form clusters, thus lowering the number of available vanadia, hence decreasing the number of available active sites on the catalyst surface to promote the reaction. The properties of the composite of vanadium and uorapatite are more tunable (stability and acidity) than uorapatite or vanadia alone.…”

Recent Progress in the Multicomponent Synthesis of Pyran Derivatives by Sustainable Catalysts under Green Conditions

“…Because of the improved productivity and substantial time saving, multicomponent reactions (MCRs) are recognised as reliable synthetic green methodologies [ 21 , 28 , 29 , 30 , 31 ]. Several advantages of MCRs driven by green credentials are crucial in organic synthesis and drug discovery programs [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ]. Hence, chemists focused on eco-friendly methods to build heterocyclic molecules under sustainable green protocols.…”