Synthesis of pyrazole-4-carbonitrile derivatives in aqueous media with CuO/ZrO2 as recyclable catalyst (original) (raw)
Related papers
Current Chemistry Letters, 2018
An ecofriendly methods for the synthesis of medicinally important class of heterocyclic scaffold, pyrazole 4-carbonitrile derivatives by one pot three component reaction of malononitrile, phenyl hydrazine and aromatic aldehyde has been achieved at room temperature. Greener protocols of reaction are followed by using sodium chloride to accelerate the reaction in aqueous media. Present methodology is a condition based divergence on synthesis of pyrazole by using simple salts, which offers several advantages like use of aqueous media and high yield of product along with short reaction time, simple work up procedure, no waste or by products, avoid the use of heavy metals or nanoparticles are the fascinating characteristics of reaction.
Green Synthesis Of 6-Amino 1, 4 Dihydropyrano[2,3-c]Pyrazole-5-Carbonitrile Under Aqueous Medium
IJRAR, 2022
An eco-friendly benign multi-component reaction in aqueous medium in the presence of SiO2-TiCl4 has been developed for the synthesis of 1,4 dihydropyrano[2,3-c]pyrazole-5-carbonitrile.The present study follows green protocol starting with aromatic aldehyde, malonitrile, ethyl acetate, hydrazine hydrate reacted under aqueous medium to produce pyranopyrazole. The presented method is mild, eco-friendly, economic, efficient, energy saving and functionality tolerant and gives the products in good to excellent yields.SiO2-TiCl4 Catalyst works effectively without any further side product. The key advantage of catalyst is that it is isolated easily at the end of reaction without any tedious procedure; reported pyranopyrazole derivative is confirmed by spectroscopic tools.i.e NMR, Mass, IR.
Greener and Environmentally Benign Methodology for the Synthesis of Pyrazole Derivatives
ChemistrySelect, 2020
Pyrazole and its derivatives are one of the interesting heterocyclic compounds among the other because it has tremendous important bio-medical applications such as anticancer, antimalarial, antimicrobial, antifungal, antitubercular and antihelishmanial. Synthesis of pyrazoles by synthetic route requires harsh reaction conditions such as organic solvent, high temperature, require large time that consume more energy which increase final cost of the synthesis of pyrazoles. Therefore researchers be aware about synthesis and give more attention towards to develop a greener as well as economically favorable method for synthesis of pyrazoles such as microwave irradiation, ultra-sonication assisted, reaction at room temperature, solvent and catalyst free and use of universal solvent that is aqueous medium these techniques are environmentally friendly as well as cost effective. Therefore, these review highlights the greener methodologies for the synthesis of pyrazoles, which are good alternative for synthetic methods that sustains green principles.
Research on Chemical Intermediates, 2021
Heterocyclic chemistry has fascinated the researchers owing to its wide range of applications in various chemical fields. With this perspective, herein we present an environmentally benign procedure for the synthesis of pyrazole and its derivatives through multicomponent reaction by using SPVA as a heterogeneous acid catalyst. The synthesis protocol of SPVA catalyst includes functionalization of polyvinyl alcohol by sulfonic acid groups. The synthesized SPVA catalyst was then subjected to several characterization techniques to confirm its formation and study its physicochemical properties. The SPVA catalyst was then tested for its activity toward a multicomponent reaction of aromatic aldehyde, malononitrile and phenyl hydrazine. The SPVA catalyst with sufficient acidic sites displayed appreciable catalytic performance yielding 89% of the desired pyrazole product under ambient reaction conditions. The SPVA catalyst showed recyclability up to the sixth cycle without considerable loss in its activity. Furthermore, we made an effort to demonstrate the plausible mechanistic pathway for the SPVA-catalyzed pyrazole synthesis reaction. Interestingly, the present synthetic approach could effectively produce pyrazole products with high yields in the absence of base and solvent and in short reaction time making it a green and sustainable process.
ChemistrySelect, 2019
The homogenous catalytic system "FeCl 3 /PVP" and green solvent system "water/PEG-400" has been presented as a green pathway to synthesize 4-amino-1-aryl-1H-pyrazole-4-carbonitrile and its derivatives from a series of phenyl hydrazines and malononitriles. The new approach enhanced the reaction yield of the desired product up to 97% in 2-4 h time whereas the traditional thermal method gives only 87% maximum yield in relatively longer reaction time (3-7 h). The catalytic system has remarkable benefits such as it is inexpensive, stable, easy to prepare and very efficient with a small loading of FeCl 3 (5 mol %).
Acta chimica Slovenica, 2013
Two efficient and convenient procedures for the synthesis of 6-amino-3-methyl-1,4-diphenyl-1,4-dihydropyrano[2,3c]pyrazole-5-carbonitrile derivatives based on four-component reaction involving ethyl acetoacetate, phenylhydrazine, malononitrile, and various aromatic aldehydes using trichloroacetic acid or ceric sulfate as heterogeneous catalysts in excellent yields and short reaction times have been described.
Pyrazole Scaffold: Strategies toward the Synthesis and Their Applications
IntechOpen eBooks, 2022
Pyrazoles have a wide range of applications in medicinal chemistry, drug discovery, agrochemistry, coordination chemistry, and organometallic chemistry. Their popularity has skyrocketed since the early 1990s. Basically, Pyrazole (C 3 H 3 N 2 H) is a simple doubly unsaturated five membered heterocyclic aromatic ring molecule comprising two nitrogen (N) atoms at positions 1-and 2-and three carbon (C) atoms. Pyrazole nucleus is synthesized with various strategies such as multicomponent approach, dipolar cycloadditions, cyclocondensation of hydrazine with carbonyl system, using heterocyclic system and multicomponent approach. A special emphasis is placed on a thorough examination of response processes. Furthermore, the reasons for the increasing popularity of pyrazoles in several fields of science are examined. Pyrazoles have recently been the focus of many techniques, mostly because of how frequently they are used as scaffolds in the synthesis of bioactive chemicals and reactions in various media. The goal of this chapter is to discuss the current developments in synthetic techniques and biological activity related to pyrazole derivatives. The many pharmacological functions of the pyrazole moiety and different synthesis techniques were discussed. This chapter has summarized novel strategies and wide applications of pyrazole scaffold.
Recent Advances in the Synthesis of Pyrazole Derivatives: A Review
Reactions
Pyrazole, characterized by a five-membered heterocyclic structure featuring two neighboring nitrogen atoms, serves as a core element. Pyrazoles hold a privileged status as versatile frameworks in various sectors of the chemical industry, including medicine and agriculture. Previous reviews have extensively highlighted the significance of pyrazoles and their diverse biological activities, encompassing roles such as antituberculosis, antimicrobial, antifungal, anti-inflammatory, anticancer, and antidiabetic agents. Consequently, they have garnered substantial interest from researchers. The aim of this review is to offer a comprehensive overview of the published research related to the synthesis of pyrazole derivatives, encompassing a discussion of diverse methods for accessing the pyrazole moiety. These methods span from utilizing transition-metal catalysts and photoredox reactions to employing one-pot multicomponent processes, novel reactants, and innovative reaction types. It encomp...