Synthesis, Anti-inflammatory, Analgesic and Antipyretic Activity of Novel 1,3,5-Trisubstituted Pyrazole Derivatives

Abstract

A novel series of 1,3,5-trisubstituted pyrazole derivatives were synthesized by the cycloaddition reaction between the electron rich N-substituted aryl hydrazones and nitro-olefins. Different N-substituted aryl hydrazones (1a-j) on reacting with 4-methyl-β-nitrostyrene (2) in ethylene glycol or trifluoroethanol-trifluoro acetic acid mixture (for acid stable hydrazones) at 120 ºC, yielded various 1,3,5-trisubstituted pyrazoles (3a-j). The final products were characterized by spectral analysis using Mass, NMR and IR spectroscopy. All the products were assessed for their anti-inflammatory, analgesic and antipyretic activities on Swiss albino rats. All the compounds (3a-j) exhibited noteworthy defence against inflammation, nociception and hyperthermia. Compounds (3e and 3h) disclosed better antiinflammatory, analgesic and antipyretic activities while compound 3c had highest anti-inflammatory activity compared to the standard nimesulide.

Synthesis of Antimicrobial Benzimidazole–Pyrazole Compounds and Their Biological Activities

“…Additionally, benzimidazoles treat mitochondrial dysfunction in Alzheimer’s disease [ 22 ], possess neurotropic, psychoactive, analgesic effects [ 23 ], anticoagulant proprieties [ 24 ] and are efficient agents in Diabetes mellitus [ 25 ]. Additionally, pyrazole compounds possess a diversity of biological activities as analgesic [ 26 , 27 , 28 ], anticonvulsivant [ 29 , 30 ], antitumor [ 31 , 32 , 33 , 34 ], antidiabetic [ 35 , 36 ], antimicrobial [ 37 , 38 , 39 , 40 , 41 , 42 , 43 ], antipyretic [ 44 , 45 ], antiviral [ 46 , 47 ], antimalarial [ 48 , 49 ], local anesthetic [ 50 ] and so forth.…”

5-(4-Fluorophenyl)-3-(naphthalen-1-yl)-1-phenyl-1H-pyrazole

“…Pyrazoles and their derivatives play an important role in some biological activities in medicine. In particular, they are used for their antimicrobial [1], anti-tuberculosis [2], antiinflammatory [3], antioxidant [4], anti-tumor [5], cytotoxicity activity [6], and analgesic [7] functions. Pyrazole can be synthesized in a variety of ways, such as by Knorr reaction or through the pyrazoline pathway, which is the reaction of α, β-unsaturated ketone with hydrazine derivatives [8] or semicarbazide [9], followed by oxidative aromatization to the corresponding pyrazole molecules [10].…”