An improved synthesis of 1,3,5-triaryl-2-pyrazolines in acetic acid aqueous solution under ultrasound irradiation

Li, Ji‐Tai; Zhang, Xiao-Hui; Lin, Zheng‐Zhe

doi:10.1186/1860-5397-3-13

Cited by 69 publications

(40 citation statements)

References 10 publications

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“…These nitrogen containing heterocycles 5 are colorless liquid which have their boiling point in the range of 120-150 C 1 . Among various derivatives of pyrazolines, 4,5-dihydro-1H-pyrazole or 2-pyrazoline have been observed to be the most common derivatives 6 found to be insoluble in water but owing to its lipophilic character 7 soluble in propylene glycol. These electron rich nitrogen heterocycles 8 can be subjected to reduction or oxidation 9 .…”

Section: Introductionmentioning

confidence: 99%

4,5-Dihydro-1H-pyrazole: an indispensable scaffold

Alex

Kumar

2013

Journal of Enzyme Inhibition and Medicinal Chemistry

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Pyrazoles, categorized as nitrogen-containing heterocycles, are well known for their interminable participation in the field of perpetual research and development of therapeutical active agents. As a consequence pyrazoles became an inevitable core of numerous drugs having diverse activities. The broad spectrum of activities portrayed by the pyrazoles instigated the researchers to modify the pyrazole ring as 4,5-dihydro-1H-pyrazoles commonly known as 2-pyrazolines. The present review is a concerted effort to retrace compounds covered from 2009-till date which owe diverse biological activities to the 2-pyrazoline scaffold and also condenses the retro-synthetic approaches employed for their synthesis. This endeavor culminated in revelation that inhibitory potential varied when the substituents in particular N-substituents of 2-pyrazolines were altered.

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Section: Introductionmentioning

confidence: 99%

4,5-Dihydro-1H-pyrazole: an indispensable scaffold

Alex

Kumar

2013

Journal of Enzyme Inhibition and Medicinal Chemistry

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“…Pyrazoline is also synthesized by using microwave irradiation [10], tungsten light irradiation [11], and ultrasound irradiation [12]. Recently, various modified methods have been reported for synthesis of 2-pyrazolines by using different catalysts such as KHSO 4 [13][14][15][16][17][18][19].…”

Section: Resultsmentioning

confidence: 99%

Benzyloxyphenyl based synthesis of some novel N-acetylpyrazolines

Navale¹,

Zangade

Vibhute³

et al. 2014

J. Turk. Chem. Soc., Sect. A: Chem.

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“…Recently, many organic reactions in aqueous media have been described in the literature [13]. In 2007, Li et al [14] have synthesized 1,3,5-triaryl-2-pyrazoline with chalcones and phenyl hydrazine hydrochloride in sodium acetate-acetic acid aqueous solution under ultrasound irradiation. Pyrazolines have been exhibiting various pharmacological activities, such as analgesic [15], anti-inflammatory [16,17], antimicrobial [18,19], anti-amoebic [20,21], antitubercular [22,23], hypoglycemic [24], anticoagulant [25], antidepressant [26-28], pesticide [29], fungicide [30], antibacterial [31], and anticonvulsant activities [32].…”

Section: Introductionmentioning

confidence: 99%

Eco-friendly synthesis and antimicrobial activities of some 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines

et al. 2012

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BackgroundGreen catalyst fly ash: H2SO4 was prepared by mixing fly ash and sulphuric acid. Microwave irradiations are applied for solid phase cyclization of 5-bromo-2-thienyl chalcones and phenyl hydrazine hydrate in the presence of fly ash: H2SO4 yields, 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines. These pyrazolines were characterized by their physical constants and spectral data. The antimicrobial activities of all synthesized pyrazolines have been studied.ResultsScanning electron microscopy (SEM) analysis shows the morphology changes between fly ash and the catalyst fly ash: H2SO4. The SEM photographs with the scale of 1 and 50 μm show the fly-ash particle is corroded by H2SO4 (indicated by arrow mark), and this may be due to dissolution of fly ash by H2SO4. The yields of 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines is more than 75% using this catalyst under microwave heating. All pyrazolines showed moderate activities against antimicrobial strains.ConclusionWe have developed an efficient catalytic method for synthesis of 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines by solid phase cyclization using a solvent-free environmentally greener catalyst fly ash: H2SO4 under microwave irradiation between aryl chalcones and hydrazine hydrate. This reaction protocol offers a simple, economical, environment friendly, non-hazardous, easier work-up procedure, and good yields. All synthesized pyrazoline derivatives showed moderate antimicrobial activities against bacterial and fungal strains.

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An improved synthesis of 1,3,5-triaryl-2-pyrazolines in acetic acid aqueous solution under ultrasound irradiation

Abstract: Background

Cited by 69 publications

References 10 publications

4,5-Dihydro-1H-pyrazole: an indispensable scaffold

4,5-Dihydro-1H-pyrazole: an indispensable scaffold

Benzyloxyphenyl based synthesis of some novel N-acetylpyrazolines

Eco-friendly synthesis and antimicrobial activities of some 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines

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