New “Green” Approaches to the Synthesis of Pyrazole Derivatives

Corradi, Anna; Leonelli, Cristina; Rizzuti, Antonino; Rosa, Roberto; Veronesi, Paolo; Grandi, Romano; Baldassari, Sara; Villa, Carla

doi:10.3390/12071482

Cited by 47 publications

(26 citation statements)

References 16 publications

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“…Regardless of the existence of the so-called "specific" or "nonthermal" microwave effects, which is still the subject of an intense debate in the scientific community (33)(34)(35)(36)(37)(38), the peculiarities of microwave heating, such as its volumetric nature and its selectivity, are at the basis of unquestionable advantages in organic (39)(40)(41)(42)(43)(44) and inorganic (45)(46)(47)(48) chemistry, as well as in the materials science (49)(50)(51)(52) field.…”

Section: Numerical Simulation Resultsmentioning

confidence: 99%

Microwave Selective Thermal Development of Latent Fingerprints on Porous Surfaces: Potentialities of the Method and Preliminary Experimental Results

Rosa

Veronesi

Leonelli

2013

Journal of Forensic Sciences

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The thermal development of latent fingerprints on paper surfaces is a simple, safe, and chemicals-free method, based on the faster heating of the substrate underlying the print residue. Microwave heating is proposed for the first time for the development of latent fingerprints on cellulose-based substrate, in order to add to the thermal development mechanism the further characteristic of being able to heat the fingerprint residues to a different extent with respect to the substrate, due to the intrinsic difference in their dielectric properties. Numerical simulation was performed to confirm and highlight the selectivity of microwaves, and preliminary experimental results point out the great potentialities of this technique, which allowed developing both latent sebaceous-rich and latent eccrine-rich fingerprints on different porous surfaces, in less than 30 sec time with an applied output power of 500 W. Microwaves demonstrated more effectiveness in the development of eccrine-rich residues, aged up to 12 weeks.

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Section: Numerical Simulation Resultsmentioning

confidence: 99%

Microwave Selective Thermal Development of Latent Fingerprints on Porous Surfaces: Potentialities of the Method and Preliminary Experimental Results

Rosa

Veronesi

Leonelli

2013

Journal of Forensic Sciences

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“…Moreover the great advantages of the MW-assisted solvent-free synthetic protocol proposed here in a "green chemistry" context and as already demonstrated in previous work [72][73][74], should be emphasised.…”

Section: Mw Assisted Hydrothermal Clay Intercalationmentioning

confidence: 94%

Microwaves-Mediated Preparation of Organoclays as Organic-/Bio-Inorganic Hybrid Materials

Villa¹,

Rosa²,

Corradi³

et al. 2011

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An innovative approach in the field of nanomaterials is to develop modern and mild synthetic protocols that enable controlled and integrated organization of specific functional organic and biological building blocks. In this context, research on the preparation of clay-based organic-inorganic hybrid materials, i.e. organoclays, has received considerable attention because these lamellar materials not only possess highly ordered structure in 2D, but also provide interesting chemical intercalation and surface properties. As a result entrapment and orientation of various functional guest molecules into layered inorganic solids, has been well exploited.At present there is a great deal of interest in the rational design of hybrid organic-/bio-inorganic composites on the nanometer to micrometer length scales. These hybrids encompass highly selective recognition properties associated with organic and biological species, combined with catalytic, optical, and electronic properties of the inorganic lamellar framework. This paper presents an overview of microwave application in different preparation steps of organophilic clays, their modification and their addition to polymeric matrices. Particular attention has been given to the microwave-mediated hydrothermal technique, as innovative and eco-friendly protocol for the intercalation of different kinds of organic hosts into the interlayer of clay minerals. The few pioneering complete microwave-mediated preparation procedures, exploiting advantages of dielectric heating in both the synthesis of the organic host molecule and the intercalation in the clay structure, have been also highlighted.

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“…Pyrazolines are prepared mainly by cyclization of chalcones with hydrazines 16,20,23 , from 1,3-dipolar cycloaddition reactions of nitrile imines to alkenes 26 by heating 27 or under microwaves 28 or from the cyclocondensation of hydrazines with 1,3-dihalides under MW irradiation 29 . Pyrazoles are synthesized mainly by the reaction of hydrazines with b-difunctional compounds 30 , from tosylhydrazones of a,b-unsaturated ketones under MW irradiation 31 and by 1,3-dipolar cycloaddition reactions of tosylhydrazone salts 32,33 or nitrile imines 25 with alkynes. In continuation to our work in the field of modified homo-N-nucleosides, we present here the reactions of 9-allyl-6-chloropurine with nitrile imines under MW irradiation and the replacement of chlorine by amines in the above products (Schemes 1 and 2).…”

Section: Introductionmentioning

confidence: 99%

Synthesis and biological evaluation of modified purine homo-N-nucleosides containing pyrazole or 2-pyrazoline moiety

Thalassitis

Katsori

Dimas

et al. 2013

Journal of Enzyme Inhibition and Medicinal Chemistry

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9-Substituted (pyrazol-5-yl)methyl-or (2-pyrazolin-5-yl)methyl-9H-purines were synthesized from 9-allyl-6-chloro-9H-purine through the 1,3-dipolar cycloaddition reaction with nitrile imines, prepared in situ from the corresponding hydrazone and NBS/Et 3 N under MW or from hydrazinoylchloride and Et 3 N under reflux. The coupling of new 6-chloropurines with amines in H 2 O under microwaves resulted quantitatively to modified pyrazol-5-yl-or 2-pyrazolin-5-yl adenine homo-N-nucleosides. The new compounds were tested in vitro for their ability to: (i) interact with 1,1-diphenyl-2-picryl-hydrazyl (DPPH), (ii) inhibit lipid peroxidation, (iii) inhibit the activity of soybean lipoxygenase, (iv) inhibit in vitro thrombin and for (v) their antiproliferative and cytotoxic activity. Pyrazolines were found to be more potent in vitro. Compound 7a exhibited satisfactory combined antioxidant and anti-lipid peroxidation activity, inhibition of lipoxygenase (89%) and thrombin inhibitory ability, whereas compound 7b exhibited high lipoxygenase inhibitory activity in combination to significant anti-thrombin activity. No compound exhibited a significant cytotoxic activity, while all showed moderate antiproliferative activity.

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New “Green” Approaches to the Synthesis of Pyrazole Derivatives

Cited by 47 publications

References 16 publications

Microwave Selective Thermal Development of Latent Fingerprints on Porous Surfaces: Potentialities of the Method and Preliminary Experimental Results

Microwave Selective Thermal Development of Latent Fingerprints on Porous Surfaces: Potentialities of the Method and Preliminary Experimental Results

Microwaves-Mediated Preparation of Organoclays as Organic-/Bio-Inorganic Hybrid Materials

Synthesis and biological evaluation of modified purine homo-N-nucleosides containing pyrazole or 2-pyrazoline moiety

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