- “On-water” one-pot four-component synthesis of novel 1H-furo[2,3-c]pyrazole-4-amine derivatives
-
A catalyst-free, simple and green protocol has been accomplished for the synthesis of novel 1H-furo[2,3-c]pyrazole-4-amines in a one-pot four-component domino reaction involving hydrazines, ethyl acetoacetate, aromatic amines and phenylglyoxal monohydrate in water. The protocol presented herein describes in situ generated pyrazolone as intermediate reactants with phenylglyoxal monohydrate in a Knoevenagel condensation followed by a Michael addition of amine, intramolecular cyclization, dehydration and the resulting to the title compound. It was observed that in this protocol bis(pyrazole-5-ols) are formed with amines bearing strong electron withdrawing groups under similar reaction conditions instead of the expected products. The reaction merits the use of water as solvent, no additive catalyst, easy workup, easy purification of products by non-chromatography and provides high yield of products with good purity.
- Noruzian, Fatemeh,Olyaei, Abolfazl,Hajinasiri, Rahimeh
-
-
Read Online
- Reaction of 3,5-carbonyl-substituted 1,4-dihydropyridines with hydrazine hydrate
-
The interaction of 3,5-carbonyl-substituted derivatives of 1,4-dihydropyridine and some analogs of it with hydrazine hydrate occurs with fission of the heterocycle. In the case of alkoxycarbonyl-substituted compounds a reverse Michael reaction predominate
- Bisenieks,Uldrikis,Duburs
-
-
Read Online
- Meglumine catalyzed one pot synthesis of new fluorescent 2-amino-4-pyrazolyl-6-aryldiazenyl-4H-chromene-3-carbonitriles
-
Meglumine, a biodegradable basic organo-catalyst has been efficiently explored for the one-pot synthesis of new fluorescent 2-amino-4-(5-hydroxy-3-methyl-1H-pyrazol-4-yl)-6-aryldiazenyl-4H-chromene-3-carbonitriles in an aqueous medium at room temperature. The synthesized compounds were found highly fluorescent when screened for photoluminescence properties. The planar structure equipped with substituted aryldiazenyl group led to the extension of conjugation that facilitated fluorescence emission in the visible region with a large stokes shift of 290–294 nm. The novelty of work is a synthesis of highly conjugated molecular assembly, high yield in shorter reaction time, energy efficiency, atom economy, utilization of water as a universal green solvent and meglumine as an eco-benign organo-catalyst.
- Korade, Suyog N.,Mhaldar, Pradeep M.,Kulkarni, Prafulladatta P.,Rashinkar, Gajanan S.,Pore, Dattaprasad M.
-
-
Read Online
- Synthesis of 1,3,5-Trisubstituted Pyrazoles and Hydrazones Using Fe3O4?CeO2 Nanocomposite as an Efficient Heterogeneous Nanocatalyst
-
Abstract: Pyrazoles and hydrazones, as two significant kinds of potentially bioactivecompounds, were produced with good to excellent yields by condensation ofβ-dicarbonyl compounds with hydrazines in aqueous media in the presence ofFe3O4?CeO2nanocomposite as an efficient heterogeneous nanocatalyst. The magneticnanocatalyst can readily be separated using an external magnet and reused atleast six times without significant loss in activity. The products werecharacterized by IR and 1H and13C NMR spectra.
- Hassani, H.,Jahani, Z.
-
p. 485 - 490
(2020/04/27)
-
- Solvent-free ring cleavage hydrazinolysis of certain biginelli pyrimidines
-
Certain Biginelli pyrimidines with ester substitution in C5 were subjected to unexpected ring opening upon solvent-free reaction with hydrazine hydrate to give three products: pyrazole, arylidenehydrazines, and urea/thiourea, respectively. The nonisolable carbohydrazide intermediates are formed firstly followed by the intermolecular nucleophilic attack of terminal amino group of hydrazide function on sp2 C6 rather than the sp3 C4 to give the ring adduct which was produced as a final product.
- Said, Mohamed A.,Eldehna, Wagdy M.,Ghabbour, Hazem A.,Kabil, Maha M.,Al-shakliah, Nasser S,Abdel-Aziz, Hatem A
-
-
- Focal adhesion kinase inhibitor and use
-
The invention belongs to the field of medicines, relates to a focal adhesion kinase inhibitor and use, in particular relates to a novel focal adhesion kinase inhibitor compound, or stereoisomers, geometric isomers, tautomers, oxynitrides, hydrates, solvates, metabolites, pharmaceutically acceptable salts or prodrugs thereof, further relates to the use of the compound and pharmaceutical compositions as medicines, in particular the use of the compound and pharmaceutical compositions in manufacture of medicines for treatment or prevention of cancer, pulmonary hypertension, and pathological angiogenesis-related diseases.
- -
-
Paragraph 0639; 0641; 0642
(2019/01/08)
-
- Method for preparing pyridinyl-pyrazole compound
-
The invention discloses a method for preparing a pyridinyl-pyrazole compound of 1-(2-aminopyridine-4-yl)-3-methyl-1H-pyrazole-5-ol. Ethyl acetoacetate is adopted a starting raw material, and the target product is obtained through cyclization, condensation and reduction. The compound is an important pharmaceutical intermediate.
- -
-
Paragraph 0018; 0019; 0020
(2018/06/16)
-
- Preparation method of pyrazole compound
-
The invention discloses a preparation method of a pyrazole compound, namely 1-(3-amino-5-(trifluoromethyl)phenyl)-3-methyl-1H-pyrazol-5-ol. The preparation method takes ethyl acetoacetate as a starting raw material and a target product is obtained through ring closure, condensation and reduction; the compound is an important pharmaceutical intermediate.
- -
-
Paragraph 0018; 0019; 0020
(2017/08/29)
-
- Preparation method of pyrazole compound
-
The invention discloses a preparation method of a pyrazole compound, namely 1-(3-nitrophenyl)-3-methyl-1H-pyrazole-5-chloride. The preparation method comprises the following steps: with ethyl acetoacetate as an initial raw material, performing ring closing, condensation and chlorination to obtain the target product. The compound is an important medical intermediate.
- -
-
Paragraph 0019; 0020
(2017/10/23)
-
- Preparation method of benzene substituted pyrazole derivative
-
The invention discloses a preparation method of a benzene substituted pyrazole derivative of 1-(3-trifluoromethylphenyl)-3-methyl-1H-pyrazole-5-chlorine. The preparation method comprises the following steps: by using ethyl acetoacetate as an initiating raw material, closing a loop, condensing, and chlorinating, so as to obtain a target product. The compound is an important medical intermediate.
- -
-
Paragraph 0019; 0020
(2017/07/20)
-
- Preparation method of 1-substituted pyrazole compound
-
The invention discloses a preparation method of a 1-substituted pyrazole compound 1-(3-nitrophenyl)-3-methyl-1H-pyrazole-5-bromide. The preparation method comprises the following steps: taking ethyl acetoacetate as an initial raw material, and performing ring closing, condensation and bromination to obtain the target product. The compound is an important medical intermediate compound.
- -
-
Paragraph 0019; 0020
(2017/10/22)
-
- Application of Fe3O4@SiO2@sulfamic acid magnetic nanoparticles as recyclable heterogeneous catalyst for the synthesis of imine and pyrazole derivatives in aqueous medium
-
Sulfamic acid supported on Fe3O4@SiO2 superpara magnetic nanoparticles was successfully applied as a recyclable solid acid catalyst with a large density of sulfamic acid groups for the synthesis of pyrazole derivatives, an important class of potentially bioactive compounds. The products are obtained in high yield from the one-pot reaction procedure involving dicarbonyl compounds and hydrazines/hydrazides. This new method totally avoids the use of toxic or expensive solvents and organic acids in this reaction.
- Zakerinasab,Nasseri,Hassani,Samieadel
-
p. 3169 - 3181
(2016/04/05)
-
- Cellulose sulfuric acid as a bio-supported and efficient solid acid catalyst for synthesis of pyrazoles in aqueous medium
-
A convenient and practical method was described for the regioselective synthesis of pyrazoles from hydrazines/hydrazides and 1,3-dicarbonyl compounds via the Knorr synthesis in water with cellulose sulfuric acid (CSA) as a biopolymer-based solid acid catalyst. Various hydrazines and hydrazides were reacted with 1,3 diketones and the desired pyrazoles were obtained in high yields. The reaction of less reactive hydrazines with 1,3-dicarbonyl compounds stopped at the corresponding hydrazone derivatives. Hydrazides were employed with β-ketoester, and imine adducts were the only isolated product. Simple isolation of products, mild reaction conditions, reusability of solid acid catalysts and short reaction times are advantages of this green procedure. This journal is
- Nasseri, Mohammad Ali,Salimi, Mehri,Esmaeili, Abbas Ali
-
p. 61193 - 61199
(2015/02/19)
-
- Structure-activity relationships of pyrazole derivatives as potential therapeutics for immune thrombocytopenias
-
Idiopathic or immune thrombocytopenia (ITP) is a serious clinical disorder involving the destruction of platelets by macrophages. Small molecule therapeutics are highly sought after to ease the burden on current therapies derived from human sources. Earlier, we discovered that dimers of five-membered heterocycles exhibited potential to inhibit phagocytosis of human RBCs by macrophages. Here, we reveal a structure-activity relationship of the bis-pyrazole class of molecules with -C-C-, -C-N- and -C-O- linkers, and their evaluation as inhibitors of phagocytosis of antibody-opsonized human RBCs as potential therapeutics for ITP. We have uncovered three potential candidates, 37, 47 and 50, all carrying a different linker connecting the two pyrazole moieties. Among these compounds, hydroxypyrazole derivative 50 is the most potent compound with an IC50 of 14 ± 9 μM for inhibiting the phagocytosis of antibody-opsonized human RBCs by macrophages. None of the compounds exhibited significant potential to induce apoptosis in peripheral blood mononuclear cells (PBMCs). Current study has revealed specific functional features, such as up to 2-atom spacer arm and alkyl substitution at one of the N1 positions of the bivalent pyrazole core to be important for the inhibitory activity.
- Purohit, Meena K.,Chakka, Sai Kumar,Scovell, Iain,Neschadim, Anton,Bello, Angelica M.,Salum, Norue,Katsman, Yulia,Bareau, Madeleine C.,Branch, Donald R.,Kotra, Lakshmi P.
-
p. 2739 - 2752
(2014/05/06)
-
- PYRAZOLE DERIVATIVES AND THEIR USES THEREOF
-
The present disclosure relates to a compound of formula (I) or a pharmaceutically acceptable salt thereof; wherein U, R1, R2, R3 and Q are as defined herein. The disclosure also provides a method for treating or preventing a method for the prevention, treatment and/or alleviation of one or more autoimmune or alloimmune disease, pharmaceutical compositions and combination comprising a therapeutically effective amount of a compound, as defined herein.
- -
-
Page/Page column 21; 22; 23
(2014/09/29)
-
- A one-pot three-component reactions for the synthesis of fully substituted spiro indeno[1,2-b]quinoxaline derivatives
-
An efficient and simple approach of the synthesis of some spiro indeno[1,2-b]quinoxalines via a one-pot three-component reaction of 11H-indeno[1,2-b]quinoxalin-11-one, pyrazolone, and malononitrile in the presence of Na2CO3 at 70 C is reported. This reaction has shown to have high atom economy.
- Soleimani, Ebrahim,Hariri, Mina,Saei, Parisa
-
p. 773 - 777
(2013/09/02)
-
- PEG-SO3H as a mild, efficient and green catalytic system for the synthesis of pyrazole derivatives in aqueous medium
-
A versatile, alternative and environmentally benign strategy for the synthesis of a series of pyrazoles has been successfully performed in water using PEG-SO3H as an acidic catalyst. The products are obtained in high yield from the one-pot reaction procedure involving dicarbonyl compounds and hydrazines/hydrazides. This new method totally avoids the use of organic acids and toxic or expensive solvents in this reaction. The catalyst is waste-free, easily prepared, and efficiently re-used.
- Nasseri,Alavi,Zakeri Nasab
-
p. 213 - 219
(2013/07/26)
-
- PYRAZOLE AND PYRROLE COMPOUNDS USEFUL IN TREATING IRON DISORDERS
-
This invention is directed to pyrazole and pyrrole compounds, for example, compounds of formula (I): wherein R1, R2, R3 and R4 are as defined herein, as stereoisomers, enantiomers, tautomers thereof or mixtures thereof; or pharmaceutically acceptable salts, solvates or prodrugs thereof, for the treatment of iron disorders. This invention is also directed to pharmaceutical compositions comprising the compounds and methods of using the compounds to treat iron disorders.
- -
-
Page/Page column 67-68
(2008/12/04)
-
- An improved preparation of 3-alkoxypyrazoles
-
The condensation between alkyl acetoacetates and hydrazines constitutes the very well-known Knorr synthetic method leading to pyrazol-3/5-ones. However, contemporary reports describe an alternate reaction pathway leading to low yields of 3/5-alkoxypyrazoles using hydrazine salts. No general method for the selective synthesis of 3-alkoxypyrazoles has been reported to date, hence we focused on this side reaction in an attempt to turn it into the main transformation. Depending on the starting material, various 3-alkoxypyrazoles (methoxy, ethoxy, benzyloxy, isopropoxy, allyloxy) were obtained in up to 56% yield. Georg Thieme Verlag Stuttgart.
- Guillou, Sandrine,Bonhomme, Frederic J.,Janin, Yves L.
-
body text
p. 3504 - 3508
(2009/05/09)
-
- Synergistic catalysis of dimetilan hydrolysis by metal ions and organic ligands
-
Hydrolysis of the insecticide dimetilan, which possesses a N,N-dimethylcarbamate moiety and a N,N-disubstituted urea moiety, has been used to explore metal ion-organic ligand synergistic effects on the degradation of agrochemicals. Dimetilan hydrolysis is strongly catalyzed by +II transition metal ions exhibiting strong affinities for nitrogen- and oxygen-donor ligands (Ni(II), Cu(II), and Zn(II)) but not Pb(II), which exhibits only a weak affinity. Comparisons among these four metal ions strongly suggest that metal ion coordination of dimetilan is necessary for catalysis to occur. A combined mechanism of metal ion coordination of dimetilan and the generation of a MeOH+ nucleophile is most plausible for the metal-catalyzed hydrolysis. In the absence of metal ions, citric acid (CIT), ethylenediamine (EN), and N-(2-hydroxyethyl)ethylenediamine (HEEN) ligands alone do not affect dimetilan hydrolysis. However, addition of these ligands significantly changes the catalytic effect of metal ions. CIT and EN reduce the capability of free metal ions to catalyze agrochemical hydrolysis. In contrast, HEEN enhances the catalytic effect of metal ions on dimetilan hydrolysis. The hydroxyl group of HEEN is believed to facilitate metal ion catalysis by acting as an intramolecular nucleophile or general base catalyst within the dimetilanmetal ion-HEEN ternary complex. This study provides a few examples of many possible synergistic/cooperative effects of metal ions and organic ligands in the environment often demonstrated in biological systems such as extracellular enzymes.Hydrolysis of the insecticide dimetilan, which possesses a N,N-dimethylcarbamate moiety and a N,N-disubstituted urea moiety, has been used to explore metal ion-organic ligand synergistic effects on the degradation of agrochemicals. Dimetilan hydrolysis is strongly catalyzed by +II transition metal ions exhibiting strong affinities for nitrogen- and oxygen-donor ligands (NiII CuII, and ZnII) but not PbII, which exhibits only a weak affinity. Comparisons among these four metal ions strongly suggest that metal ion coordination of dimetilan is necessary for catalysis to occur. A combined mechanism of metal ion coordination of dimetilan and the generation of a MeOH+ nucleophile is most plausible for the metal-catalyzed hydrolysis. In the absence of metal ions, citric acid (CIT), ethylenediamine (EN), and N-(2-hydroxyethyl)ethylenediamine (HEEN) ligands alone do not affect dimetilan hydrolysis. However, addition of these ligands significantly changes the catalytic effect of metal ions. CIT and EN reduce the capability of free metal ions to catalyze agrochemical hydrolysis. In contrast, HEEN enhances the catalytic effect of metal ions on dimetilan hydrolysis. The hydroxyl group of HEEN is believed to facilitate-metal ion catalysis by acting as an intramolecular nucleophile or general base catalyst within the dimetilan-metal ion-HEEN ternary complex. This study provides a few examples of many possible synergistic/cooperative effects of metal ions and organic ligands in the environment often demonstrated in biological systems such as extracellular enzymes.
- Huang, Ching-Hua,Stone, Alan T.
-
p. 4117 - 4122
(2007/10/03)
-
- SYNTHESE DE NOUVEAUX SYSTEMES HETEROCYCLIQUES : LES PYRAZOLOTRIAZOLOBENZODIAZEPINES
-
The synthesis of new pyrazolotriazolobenzodiazepines have been described.Hydrazinolysis of pyrazolobenzodiazepinethiones leads to 7-pyrazolylamino indazole.
- Benchidmi, M.,Essassi, E. M.,Ibnmansour, A.
-
p. 995 - 1000
(2007/10/02)
-
- Pyrimidine Derivatives and Related Compounds. Part 42. Isolation of the Intermediates in the Ring Transformation of 1,3-Oxazine-2,4-diones into Pyrimidines and Pyrasoles, and their Structure Determination by 15N Nuclear Magnetic Resonance Analysis
-
Reaction of the 6-methyl-1,3-oxazine-2,4-diones (1) and (2) with hydrazine hydrate at room temperature gave the 6-hydroxy-5,6-dihydrouracils (7a) and (8a).The structures of the products were determined by 15N n.m.r. analysis.The mechanism of the ring transformation of 1,3-oxazines into pyrimidines and pyrazoles is discussed.
- Yogo, Motoi,Hirota, Kosaku,Senda,Shigeo
-
p. 473 - 475
(2007/10/02)
-
- Nuclear magnetic resonance study of addition-cyclization involving ethyl thioacetoacetate and α-nucleophiles
-
Addition of NH2NH2 or NH2OH to ethyl thioacetoacetate to form the corresponding cyclic product, 3-methylpyrazol-5-one or 3-methylisoxazol-5-one proceeds via cyclization of the carbinolamine formed by addition to the β-keto carbon, i.e., cyclization is faster than dehydration of the carbinolamine to form the imine.In contrast the corresponding carbinolamine derived from ethylacetoacetate undergoes dehydration faster than cyclization.By means of 1H nuclear magnetic resonance spectroscopy, it is possible to detect the cyclic carbinolamine as well as another transient and measure their rates of decay.Based on these results, a mechanism is proposed.
- Cocivera, Michael,Basu, Soumen,Copp, Leslie,Malatesta, Vincenzo
-
p. 629 - 634
(2007/10/02)
-
