ChemInform Abstract: Synthesis of Isomeric Δ<sup>2</sup>‐Pyrazolines.

Thakare, V. G.; Wadodkar, K. N.

doi:10.1002/chin.198644178

Cited by 6 publications

(6 citation statements)

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“…Among the methods employed in synthesis of pyrazolines, condensation of a variety of substituted chalcones with hydrazine and its derivatives is commonly used [ 16 , 17 , 18 ]. 2-Pyrazolines can be conveniently synthesized by the treatment of α,β-unsaturated carbonyl compounds with hydrazine reagents in basic and acidic media [ 11 , 16 , 17 ]. In this method, hydrazones are formed as intermediates, which can be subsequently cyclized to 2-Pyrazolines in the presence of a suitable cyclizing reagent like acetic acid [ 19 , 20 ].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of New 3,5-Dinaphthyl Substituted 2-Pyrazolines and Study of Their Antimicrobial Activity

2002

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A number of chalcones were prepared by condensing either 1-acetylnaphthalene or substituted 1-acetylnaphthalenes with 1-naphthaldehyde or 4-dimethylamino-1-naphthaldehyde in ethanolic NaOH solutions. These chalcones were immediately reacted with hydrazine hydrochloride, phenyl hydrazine and semicarbazide hydrochloride in the presence of dry acetic acid to obtain the corresponding 2-pyrazolines. The synthesised heterocycles were characterized on the basis of their chemical properties and spectroscopic data. These compounds were tested for antimicrobial activity against a variety of test organisms: Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Proteus mirabillis, Shigella dysentry and Salmonella typhii. The compounds containing chloro, hydroxo and dimethylamino -N(CH3)2 group as substituents on the naphthalene rings have been found to be very effective antimicrobial agents. In addition, the presence of a carboxamido -CONH2 substituent group at the N-1 position of the 2-pyrazoline rings is shown to contribute substantially to the antimicrobial activity.

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Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of New 3,5-Dinaphthyl Substituted 2-Pyrazolines and Study of Their Antimicrobial Activity

2002

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“…In particular, they are reported to be potent antibiotic and antioxidizing agents. [1][2][3][4][5][6][7][8][9] Hence, methods for generating this type of heterocycle are very attractive. [10][11][12][13][14][15][16][17][18][19] Several sydnone derivatives are associated with a wide range of physiological activities including antimicrobial, anti-inflammatory, analgesic and antipyretic activities.…”

Section: Heterocyclic Analogues Of Chalcones Have Been Preparedmentioning

confidence: 99%

A Concise Synthetic Method for Sydnonyl-Substituted Pyrazoline Derivatives

Shih¹

2003

Synthesis

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The pyrazolines have been found to have diverse applications in medicine. They are known to be potent antibiotic or antioxidizing agents. Two types of sydnonyl-substituted a,bunsaturated ketones were synthesized by the Claisen-Schmidt condensation for the preparation of sydnonyl-substituted pyrazolines. One is the condensation of 3-(4-ethoxyphenyl)-4-formylsydnone (1) with acetone (2a) or acetophenone (2b), and the other is the condensation of 4-acetyl-3-arylsydnones 5 with various aryl aldehydes 6. Finally, 1H-pyrazoline derivatives 8 were synthesized successfully by reacting the appropriate a,b-unsaturated ketone precursors 7 with hydrazine hydrate.Heterocyclic analogues of chalcones have been prepared for biological studies. The a,b-unsaturated ketones can play as versatile precursors in the syntheses of the corresponding pyrazoline derivatives. 1-5 Moreover, the pyrazolines have been found to have diverse applications in medicine and agriculture. In particular, they are reported to be potent antibiotic and antioxidizing agents. 1-9 Hence, methods for generating this type of heterocycle are very attractive. 10-19 Several sydnone derivatives are associated with a wide range of physiological activities including antimicrobial, anti-inflammatory, analgesic and antipyretic activities. 20-22 Consequently, chemists still enthusiastically pursue the syntheses of sydnone derivatives. 23-28 Following reports of these activities, this study seeks to synthesize a series of pyrazolines that contain the sydnonyl moiety, with the aim of obtaining new biologically active compounds.The pyrazolines are usually prepared by the reactions of of a,b-unsaturated ketones and hydrazine hydrate. Although well known, this reaction has never been applied to the sydnone systems. Prompted by the biological activities of heterocyclic compounds and earlier interest in incorporating heterocyclic moieties in sydnones, [29][30][31][32][33][34][35] it was contemplated to synthesize some new sydnones that have pyrazolinyl moieties. In this present study, 4-[3-(4-ethoxyphenyl)sydnon-4-yl]but-3-en-2-one (3a) or 3-[3-(4-ethoxyphenyl)sydnon-4-yl]-1-phenylprop-2-en-1-one (3b) were prepared in high yields from the reaction of 3-(4-ethoxyphenyl)-4-formylsydnone (1) with acetone (2a) or acetophenone (2b) by the Claisen-Schmidt condensation 36,37 (Scheme 1). Treatment of compound 3a or 3b with hydrazine hydrate in 95% ethanol under various temperature conditions did not yield the desired cyclization product 4 (Scheme 1) though a crude solid was isolated. This condensation solid product was characterized as a hydrazone of compound 3 according to the IR and NMR analyses. This result implied that the electron-releasing property of 4-sydnonyl group may increase the electron density on the carbon-carbon double bond of a,b-unsaturated ketones and hinder the Michael addition of hydrazine to the a,bunsaturated ketones 3. Scheme 1 1: Ar = p-C 2 H 5 OC 6 H 4 ; 2a: R¢ = CH 3 ; 2b: R¢ = C 6 H 5To solve this problem, another type of sydnonyl-substituted a,b-unsaturat...

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“…Among the methods employed in synthesis of pyrazolines, condensation of substituted chalcones with hydrazine and its derivatives is commonly used (Knorr, 1893;Thakare and Wadodkar, 1986;Ankhiwala and Hathi, 1996;Azarifar and Ghasemnejad, 2003). In view of the importance of 2-pyrazolines and in continuation of our work on pyrazolines Jasinski et al, 2010a, b;Fun et al, 2010;Baktir et al, 2011), we report the synthesis and biological evaluation of some 1,3,5-triaryl-2-pyrazolines.…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial, analgesic, DPPH scavenging activities and molecular docking study of some 1,3,5-triaryl-2-pyrazolines

Samshuddin

Narayana

Sarojini³

et al. 2011

Med Chem Res

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A series of 1,3,5-triaryl-2-pyrazolines 2a-g were synthesized by the reaction of 4,4 0 -disubstituted chalcone with phenyl hydrazine. All these compounds were characterized by NMR, IR and mass spectral and single crystal XRD data. All the synthesized products were screened for their in vitro antimicrobial, analgesic and antioxidant properties. The docking studies were carried out for these compounds against the active site of methionyl-tRNA synthetase (metRS). Some of the tested compounds exhibited significant antimicrobial, analgesic, DPPH scavenging activities and molecular binding.

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ChemInform Abstract: Synthesis of Isomeric Δ²‐Pyrazolines.

Abstract: The reactions of the chalcones (I) with hydrazine hydrate (II) do not give the reported chalcone hydrazones but the pyrazolines (III).

Cited by 6 publications

References 0 publications

Synthesis and Characterization of New 3,5-Dinaphthyl Substituted 2-Pyrazolines and Study of Their Antimicrobial Activity

Synthesis and Characterization of New 3,5-Dinaphthyl Substituted 2-Pyrazolines and Study of Their Antimicrobial Activity

A Concise Synthetic Method for Sydnonyl-Substituted Pyrazoline Derivatives

Antimicrobial, analgesic, DPPH scavenging activities and molecular docking study of some 1,3,5-triaryl-2-pyrazolines

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ChemInform Abstract: Synthesis of Isomeric Δ2‐Pyrazolines.

Abstract: The reactions of the chalcones (I) with hydrazine hydrate (II) do not give the reported chalcone hydrazones but the pyrazolines (III).

Cited by 6 publications

References 0 publications

Synthesis and Characterization of New 3,5-Dinaphthyl Substituted 2-Pyrazolines and Study of Their Antimicrobial Activity

Synthesis and Characterization of New 3,5-Dinaphthyl Substituted 2-Pyrazolines and Study of Their Antimicrobial Activity

A Concise Synthetic Method for Sydnonyl-Substituted Pyrazoline Derivatives

Antimicrobial, analgesic, DPPH scavenging activities and molecular docking study of some 1,3,5-triaryl-2-pyrazolines

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ChemInform Abstract: Synthesis of Isomeric Δ²‐Pyrazolines.