Microwave‐assisted Synthesis of Novel 3,4‐Bis‐chalcone‐N‐arylpyrazoles and Their Anti‐inflammatory Activity

Abstract

A series of 3,4-bis-chalcone-N-arylpyrazoles 3a-h was prepared conveniently from diacetyl pyrazoles 2a,b. All reactions were carried out under conventional thermal heating and/or microwave irradiation. The structure of the latter functionally pyrazoles was confirmed under the bases of their IR, mass, 1 H NMR and 13 C NMR. The X-ray diffraction of compound 3e not only confirmed the chemical structure of 3a-h, but also showed the E configuration of their chalcone moieties. Treatment of compound 3e with phenyl hydrazine in presence of acetic acid afforded the tri-pyrazle 4. The anti-inflammatory activity of the newly synthesized compounds was investigated. Some of these compounds showed a moderate activity when compared with indomethacin as a reference drug. The combination between chalcone and pyrazole moieties revealed a variable effect in anti-inflammatory activity.

Synthesis and Biological Evaluation of Some N‐Arylpyrazoles and Pyrazolo[3,4‐d]pyridazines as Anti‐Inflammatory Agents

“…The reaction of 2‐oxo‐ N ′‐arylpropanehydrazonoyl chlorides 1a – e with pentan‐2,4‐dione in ethanol containing sodium ethoxide gave 3,4‐diacetyl‐5‐methyl‐ N ‐arylpyrazoles 2a – e , as shown in Scheme .…”

“…Certain chalcone derivatives were reported to possess analgesic and antipyretic actions in addition to their marked anti‐inflammatory activity . Among the chalcones , 2,4‐dichloro‐4′‐ N ‐[ N ′‐(4″‐methylphenylsulfenyl)urenyl]chalcone (Me‐UCH9) was found to exert anti‐inflammatory action through dual inhibition of cyclooxygenase‐2 and 5‐lipoxygenase activities (Fig.…”

Synthesis and Antimicrobial Evaluation of Some Novel Bis-α,β-Unsaturated Ketones, Nicotinonitrile, 1,2-Dihydropyridine-3-carbonitrile, Fused Thieno[2,3-b]pyridine and Pyrazolo[3,4-b]pyridine Derivatives

“…Thus, a Claisen-Schimdt reaction of 1,1′-(5-methyl-1-phenyl-1 H -pyrazole-3,4-diyl)diethanone ( 1 ), prepared following the previously reported methods [39–41], with Furfural ( 2a ), 4-chlorobenzaldehyde ( 2b ) and 4-methoxybenzaldhyde ( 2c ), in 10% ethanolic sodium hydroxide afforded the corresponding bis(α,β-unsaturated ketons) 3a – c in 65, 95 and 50% yields, respectively (Scheme 1) [42]. …”

“…The IR spectra of 3a – c showed the appearance of carbonyl function absorption bands in the region 1663–1658 cm −1 . The 1 H-NMR spectra of 3a – c displayed the two signals of olefinic protons besides the aromatic protons [42], Thus, compound 3b , taken as a typical example of the prepared series, revealed absorption bands at 2923, 1663 and 1598 cm −1 corresponding to CH-aliphatic, two carbonyl groups and C=C functions, respectively. Its 1 H-NMR spectrum showed signals at δ 2.38 due to CH 3 protons, four duplet signals at δ 7.24 ( J = 11.3 Hz), 7.38 ( J = 10.5 Hz), 7.54 ( J = 10.5 Hz), 7.62 ( J = 11.3 Hz) due to 4 CH = protons, in addition to an aromatic multiplet protons in the region δ 7.66–7.84.…”

Recent Progress on Nicotinonitrile Scaffold‐based Anticancer, Antitumor, and Antimicrobial Agents: A Literature Review

“…Claisen–Schmidt reaction of diethanone 248 , with the appropriate aldehydes 249a – c , in 10% ethanolic sodium hydroxide gave the corresponding bischalcones 250a – c , respectively (Scheme ) . Furthermore, reaction of compounds 250a – c with malononitrile and ammonium acetate in n ‐butanol gave the corresponding nicotinonitriles 251a – c , one‐pot four‐component cyclocondensation reaction of 248 with the appropriate aldehyde 249 , malononitrile and ammonium acetate afforded compound 251a – c (Scheme ) .…”