1145-01-3Relevant academic research and scientific papers
Oxidative decarboxylation of benzilic acid by a biomimetic iron(II) Complex: Evidence for an iron(IV)-oxo-hydroxo oxidant from O2
Paria, Sayantan,Que Jr., Lawrence,Paine, Tapan Kanti
, p. 11129 - 11132 (2011)
O2-dependent transformation: An iron(II)-benzilate complex of a tridentate N3 donor ligand reacts with O2 to undergo oxidative decarboxylation. Cyclohexene is selectively converted into cis-cyclohexane-1,2- diol in the reaction. Copyright
A novel synthesis of 5-aryl-3-phenylpyrazole from 2-aryl-3-benzoyl-1,1- cyclopropanedicarbonitrile and hydrazine
Ren, Zhongjiao,Cao, Weiguo,Chen, Jie,Wang, Yu,Ding, Weiyu
, p. 495 - 497 (2006)
A new process for synthesis of 5-aryl-3-phenylpyrazole is achieved. The regioselective ring-opening reaction of 2-aryl-3-benzoyl-1,1- cyclopropanedicarbonitrile with hydrazine plays a crucial role in the described process.
New mononuclear Pd(II) complexes of sterically hindered bispyrazolylmethanes
Jones, Michael W.,Adlington, Robert M.,Baldwin, Jack E.,Le Pevelen, Delphine D.,Smiljanic, Nicolas
, p. 1097 - 1101 (2010)
Three new palladium(II) complexes incorporating the bispyrazolylmethane core have been synthesised and fully characterised in the solution and solid state. Single crystal X-ray studies revealed almost complete blocking of the upper face of the palladium ion by the substituents at the 3- and 5-positions of the pyrazole rings. Preliminary screening of the complexes for palladium(II) mediated catalysis revealed good catalytic activity for the Heck coupling reaction.
A novel one-pot method for the preparation of pyrazoles by 1,3-dipolar cycloadditions of diazo compounds generated in situ
Aggarwal, Varinder K.,De Vicente, Javier,Bonnert, Roger V.
, p. 5381 - 5383 (2003)
A convenient one-pot procedure for the preparation of pyrazoles by 1,3-dipolar cycloaddition of diazo compounds generated in situ has been developed. Diazo compounds derived from aldehydes were reacted with terminal alkynes to furnish regioselectively 3,5-disubstituted pyrazoles. Furthermore, the reaction of N-vinylimidazole and diazo compounds derived from aldehydes gave exclusively 3-substituted pyrazoles in a one-pot process.
Stereochemistry of Base-catalysed Addition of Methyl Mercaptoacetate to Acetylenic Ketones and Esters. Effects of Activating Groups and Solvents
Basyouni, Mohamed Nabih,Omar, Mohamed Tawfik,Ghali, Edwar Amin
, p. 1739 - 1742 (1980)
Piperidine-catalysed addition of methyl mercaptoacetate to benzoyl- and p-chlorobenzoyl-phenylacetylenes in ethanol gave the corresponding (Z)-1-aryl-3-(methoxycarbonylmethylthio)-3-phenyl-2-propen-1-one.However, p-anisoylphenylacetylene gave a mixture of (Z)- and (E)-3-(methoxycarbonylmethylthio)-1-(p-methoxyphenyl)-3-phenyl-2-propen-1-ones in the ratio of 4:1.This ratio was completely inverted when the latter addition was carried out in dry benzene.Rationalisation of these results is presented which depends on the effect of activating groups and solvents on thestereochemistry of addition.Piperidine-catalysed addition of methyl mercaptoacetate to methyl phenylpropiolate in ethanol gave methyl (Z)-3-(methoxycarbonylmethylthio)cinnamate.Hydrazine hydrate converted some of the above mono-adducts into some pyrazole derivatives.
Hexacarbonylmolybdenum-Induced N-N Bond Cleavage of Pyrazoles. Conversion of 1-Acylpyrazoles to Pyrimidines
Nitta, Makoto,Hamamatsu, Tatsuo,Miyano, Hiroyuki
, p. 4473 - 4475 (1988)
-induced reactions of 1-acyl-3,5-disubstituted pyrazoles underwent N-N bond cleavage and subsequent cyclocondensation to give pyrimidines as well as deacylation to give 3,5-disubstituted pyrazoles.Under similar conditions, 1,3,5-trisubstituted pyrazoles, which have no electron-withdrawing substituent on N1, gave no product, except for the starting materials.
Reactivity studies of (η6-arene)ruthenium dimeric complexes towards pyrazoles: Isolation of amidines, bis pyrazoles and chloro bridged pyrazole complexes
Govindaswamy,Mozharivskyj, Yurij A.,Kollipara, Mohan Rao
, p. 3265 - 3274 (2004)
The complex [(η6-p-cymene)Ru(μ-Cl)Cl]2 1 reacts with pyrazole ligands (3a-g) in acetonitrile to afford the amidine derivatives of the type [(η6-p-cymene)Ru(L) (3,5-HRR′pz)](BF4)2 (4a-f), where L = {HN = C(Me)3,5-RR′pz}; R, R′ = H (4a); H, CH3, CH6H5 (4c); CH3, C6 H5 (4d) OCH3 (4e); and OC2H5 (4f), respectively. The ligand L is generated in situ through the condensation of 3,5-HRR′pz with acetonitrile under the influence of [(η6-p-cymene)RuCl2]2. The complex [(η6-C6Me6)Ru(μ-Cl)Cl] 2 2 reacts with pyrazole ligands in acetonitrile to yield bis-pyrazole derivatives such as [(η6-C6 Me6)Ru (3,5-HRR′pz)2Cl](BF4) (5a b), where R, R′ = H (5a); H, CH3 (5b) as well as dimeric complexes of pyrazole substituted chloro bridged derivatives [{(η6-C6Me6)Ru(μ-Cl) (3,5-HRR′pz)}2](BF4)2 (5c-g), where R, R′ = CH3 (5c); C6H5 (5d); CH3, C6H5 (5e); OCH3 (5f); and OC2H5 (5g), respectively. These complexes were characterized by FT-IR and FT-NMR spectroscopy as well as analytical data. The molecular structures of representative complexes [(η6-C6Me6)Ru {3(5)-Hmpz}2Cl]+ 5b, [(η6- C6Me6)Ru(μ-Cl)(3,5-Hdmpz)]2 2+ 5c and [(η6-C6Me6) Ru(μ-Cl){3(5)Me,5(3)Ph-Hpz}]22+ 5e were established by single crystal X-ray diffraction studies.
Fragmenlt Recombination Design, Synthesis, and Safener Activity of Novel Ester-Substituted Pyrazole Derivatives
Fu, Ying,Gao, Shuang,Jia, Ling,Ye, Fei,Zhang, Yuan-Yuan,Zhao, Li-Xia
, p. 8366 - 8379 (2021)
Fenoxaprop-p-ethyl (FE), a type of acetyl-CoA carboxylase (ACCase) inhibitor, has been extensively applied to a variety of crop plants. It can cause damage to wheat (Triticum aestivum) even resulting in the death of the crop. On the prerequisite of not reducing herbicidal efficiency on target weed species, herbicide safeners selectively protect crops from herbicide injury. Based on fragment splicing, a series of novel substituted pyrazole derivatives was designed to ultimately address the phytotoxicity to wheat caused by FE. The title compounds were synthesized in a one-pot way and characterized via infrared spectroscopy, 1H nuclear magnetic resonance, 13C nuclear magnetic resonance, and high-resolution mass spectrometry. The bioactivity assay proved that the FE phytotoxicity to wheat could be reduced by most of the title compounds. The molecular docking model indicated that compound IV-21 prevented fenoxaprop acid (FA) from reaching or acting with ACCase. The absorption, distribution, metabolism, excretion, and toxicity predictions demonstrated that compound IV-21 exhibited superior pharmacokinetic properties to the commercialized safener mefenpyr-diethyl. The current work revealed that a series of newly substituted pyrazole derivatives presented strong herbicide safener activity in wheat. This may serve as a potential candidate structure to contribute to the further protection of wheat from herbicide injury.
Synergistic antifungal effect of cyclized chalcone derivatives and fluconazole against Candida albicans
Ahmad, Aijaz,Wani, Mohmmad Younus,Patel, Mrudula,Sobral, Abilio J.F.N.,Duse, Adriano G.,Aqlan, Faisal Mohammed,Al-Bogami, Abdullah Saad
, p. 2195 - 2207 (2017)
The occurrence of invasive fungal diseases, particularly in immunocompromised patients, is life-threatening and increases the economic burden. The rising problem of multi-drug resistance is becoming a major concern for clinicians. In addition, a repertoire of antifungal agents is far less in number than antibacterial drugs. To combat these problems, combination therapy has gained a lot of interest. We previously reported the synergistic interaction of some mono- and bis-dihydropyrimidinone and thione derivatives with fluconazole and amphotericin B for combination antifungal therapy. In this study we used the same approach and synthesized different azole and non-azole derivatives of mono-(M) and bis-(B) chalcones and evaluated their antifungal activity profile alone and in combination with the most commonly used antifungal drug-fluconazole (FLC)-against seven FLC susceptible and three FLC resistant clinically isolated Candida albicans strains. Based on the minimum inhibitory concentration results, the bis-derivatives showed lower MIC values compared to their mono-analogues. Both fractional inhibitory concentration index and isobologram results revealed mostly synergistic, additive or indifferent interactions between the tested compounds and FLC against different Candida isolates. None of the tested compounds showed any effect on energy dependent R6G efflux, revealing that they do not reverse the mechanism of drug efflux. However, surprisingly, these compounds profoundly decreased ergosterol biosynthesis and showed down regulation of ERG11 gene expression, which is the possible mechanism of reversal of azole drug resistance by these compounds. These results provide a platform for further research to develop pyrimidinone/thione ring containing compounds as promising new antifungal agents, which could be used in antifungal combination therapy.
Synthesis of [3,3′(4H,4′H)-Bi-2H-1,3-oxazine]-4,4′-diones and their hydrolysis
Korkusuz, Elif,Yildirim, Ismail
, p. 1339 - 1347 (2013)
The [3,3′(4H,4′H)-bi-2H-1,3-oxazine]-4,4′-diones 3a-3i were obtained by [2+4] cycloaddition reactions of furan-2,3-diones 1a-1c with aromatic aldazines 2a-2d (Scheme 1). So, new derivatives of bi-2H-1,3-oxazines and their hydrolysis products, 3,5-diaryl-1H-pyrazoles 4a-4c (Scheme 3), which are potential biologically active compounds, were synthesized for the first time. Copyright
