- Unexpected ring opening of pyrazolines with activated alkynes: synthesis of 1H-pyrazole-4,5-dicarboxylates and chromenopyrazolecarboxylates
-
1H-Pyrazole-4,5-dicarboxylates and chromenopyrazole carboxylates were prepared by reacting pyrazolines with activated alkynes under neat conditions without a catalyst. The products were formed via unexpected ring opening of pyrazolines with the elimination of styrene/ethylene. These types of transformations are unknown and the products formed were confirmed using their spectral/analytical data. In addition, the structures of compounds 5e and 5n were confirmed by single-crystal X-ray analysis. Control experiments were conducted to support the proposed reaction mechanism.
- Bhimapaka, China Raju,Kolla, Sai Teja,Rayala, Nageswara Rao,Sridhar, Balasubramanian
-
supporting information
p. 334 - 338
(2022/01/20)
-
- Active Base Hybrid Organosilica Materials based on Pyrrolidine Builder Units for Fine Chemicals Production
-
The catalytic activity of “pyrrolidine type” fragments included or anchored in the mesoporous silica supports or polymeric frameworks have been fully reported for enantioselective transformation. Nevertheless, low attention was focused on their catalytic abilities to perform base-catalyzed reaction. Accordingly, hybrid materials including pyrrolidine fragments in the mesoporous silica supports were prepared following different synthesis methods, such as micellar and fluoride sol-gel routes in absence of structural directing agents. Their great catalytic performance was explored for various base-catalyzed reactions to the formation of C?C bond through Knoevenagel, Claisen-Schmidt and Henry condensations under microwave irradiation. The benefits of microwave irradiation combined with suitable catalytic properties of pyrrolidine hybrid materials with strong base sites and high accessibility to active centers, allowed carrying out successfully base-catalyzed condensation reactions for the production of fine chemicals. Moreover, the hybrid catalyst exhibited high selectivity and good stability over different catalytic cycles contributing to environmental sustainability.
- Llopis, Sebastián,Velty, Alexandra,Díaz, Urbano
-
p. 5012 - 5024
(2021/10/19)
-
- TBHP/Cu(OAc)2 mediated oxidation of pyrazolines: A convenient method for the preparation of pyrazoles
-
An efficient and simple oxidative protocol has been developed for the preparation of pyrazoles from pyrazolines mediated by TBHP/Cu(OAc)2 at room temperature. The present protocol has been successfully applied for the preparation of various pyrazole compounds from heterocyclic pyrazolines.
- Kolla, Sai Teja,Somanaboina, Ramya,Bhimapaka, China Raju
-
supporting information
p. 1425 - 1432
(2021/02/27)
-
- N-para-sulfonium salt substituted pyrazoline derivative, photocurable composition and preparation method
-
The invention relates to an N-para-sulfonium salt substituted pyrazoline derivative shown as the following formula (I) in the specification, a photocurable composition, and a preparation method of theN-para-sulfonium salt substituted pyrazoline derivative shown as the following formula (I). The N-para-sulfonium salt substituted pyrazoline derivative shown as formula (I) has good absorption at a wavelength of 350nm or above, and compared with a 5-substituted sulfonium salt, the N-para-sulfonium salt substituted pyrazoline derivative has the advantages of simpler and more convenient molecule synthesis steps and reduced cost of raw materials, and is more suitable for industrial production and application.
- -
-
Paragraph 0142-0143; 0145; 0150-0151
(2020/07/21)
-
- Second harmonic generation in pyrazoline derivatives of dibenzylideneacetones and chalcone: A combined experimental and theoretical approach
-
In this work, we investigate theoretically and experimentally second harmonic generation (SHG) in three pyrazoline compounds, being two derivatives of dibenzylideneacetone (DBA) (C23H20N2 and C25H24N2O2) and one derivative of chalcone (C21H18N2). The compounds were synthesized after two steps employing a Claisen-Schmidt condensation followed by an addition-elimination reaction with phenylhydrazine. All compounds were characterized using NMR, FT-IR, UV-Vis, and XRD. We calculated the first-order hyperpolarizabilities of these molecules using program packages based on the time-dependent Hartree-Fock (TDHF) and density functional theory (DFT). SHG was characterized by Kurtz and Perry's powder method. We observed that these organic crystals present SHG efficiencies up to 5 times larger than the KDP, and we associated these values to their molecular structure and crystalline arrangements. The values obtained experimentally and theoretically evidence that these compounds have good potential for application in electronic devices based on second-order nonlinear responses.
- de Araújo, Raiane Sodré,de Alcantara, Aline Moreira,Abeg?o, Luis M.G.,de Souza, Yago Pereira,Brand?o Silva, Ant?nio Carlos,Machado, Rogério,Joatan Rodrigues, José,Rodriguez Pliego, Josefredo,d'Errico, Francesco,Siqueira Valle, Marcelo,de Alencar, Márcio André Rodrigues Cavalcanti
-
-
- Pyrazoline-based colorimetric and fluorescent probe for detection of sulphite
-
Two pyrazoline-based fluorescent and colorimetric probes have been synthesized and their photophysical properties have been investigated by means of electronic absorption and emission spectroscopy. The compounds differ from each other by the presence of a
- Uchacz, Tomasz,Jajko, Gabriela,Danel, Andrzej,Szlachcic, Pawe?,Zapotoczny, Szczepan
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p. 874 - 883
(2019/01/10)
-
- Spectroscopic studies of aryl substituted 1-phenyl-2-pyrazolines: Steric and electronic substitution effects
-
A series of aryl substituted 1-phenyl-2-pyrazolines containing electron-donating and electron-withdrawing substituents on different positions of the C3– or C5-aryl groups were synthesized and their steric and electronic effects on ch
- Soltani, Marzieh,Memarian, Hamid R.,Sabzyan, Hassan
-
p. 903 - 917
(2018/09/18)
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- Ultrasound assisted synthesis of 1,5-diaryl and 1,3,5-triaryl-2-pyrazolines by using KOH/EtOH system with Cu(I) catalyst
-
1,5-Diaryl-2-pyrazolines and 1,3,5-triaryl-2-pyrazolines were synthesized in alcoholic potassium hydroxide in high yields within 1-6 min under ultrasound irradiation at room temperature.
- Pise, Ashok S.,Jadhav, Sunil D.,Burungale, Arvind S.,Devkate, Santosh S.,Gawade, Ramesh B.
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p. 894 - 896
(2018/03/13)
-
- Microwave-irradiated synthesis and biological evaluation of 3,5-diaryl-1-phenyl-2-pyrazolines as antibacterial and anti-inflammatory agents
-
In a wide search program towards a biologically active antibacterial and anti-inflammatory agents, a series of 3,5-diaryl-1-phenyl-2-pyrazoline have been synthesized with excellent yields employing microwave techniques starting from substituted α,β-unsaturated carbonyl compounds which undergo cyclization reactions with phenylhydrazine. The structures of newly synthesized compounds were characterized and confirmed on the basis of FT-IR, 1H NMR and mass spectral analyses. The synthesized compounds 3,5-diaryl-1-phenyl-2-pyrazolines had shown significant activity against Staphylococcus aureus (MTCC 87), Escherichia coli (MTCC 40), Pseudomonas aeruginosa (MTCC 424) and Proteus vulgaris (MTCC 426) by cup plate method using tetracycline-SD 037 as a reference standard. The anti-inflammatory property of 1,3,5-diaryl-1-phenyl-2-pyrazolines were screened by using carragenan induced paw edema method in Wistar rat. The anti-inflammatory activities were comparable to that of the standard drug diclofenac. The safety of 3,5-diaryl-1-phenyl-2-pyrazolines were reflected by toxicity studies.
- Kumar, Anjan,Rout, Sradhasini,Panda, Jnyanaranjan,Sahoo, Biswa Mohan,Banik, Bimal Krishna
-
p. 1321 - 1326
(2020/06/27)
-
- TfOH mediated intermolecular electrocyclization for the synthesis of pyrazolines and its application in alkaloid synthesis
-
TfOH mediated easy access to interesting pyrazolines starting from an aldehyde, phenylhydrazine and styrene has been developed. The scope of this synthetic methodology has been explored by synthesizing various 1,3,5-trisubstituted pyrazolines in very good yields with very high regioselectivity. The origin of regioselectivity has been explained by comparing the stability of possible intermediate carbocations. The synthetic utility of a green solvent has been explored by synthesizing some of pyrazolines in a DES medium. The synthetic application of the present methodology is employed in the synthesis of a pyrazoline alkaloid.
- Annes, Sesuraj Babiola,Vairaprakash, Pothiappan,Ramesh, Subburethinam
-
p. 30071 - 30075
(2018/09/11)
-
- Catalytic Synthesis of Chalcones and Pyrazolines Using Nanorod Vanadatesulfuric Acid: An Efficient and Reusable Catalyst
-
Nanorod vanadatesulfuric acid (VSA NRs), as a recyclable and ecologically benign catalyst, was used for the one-pot synthesis of chalcones and 1,3,5-triaryl-2-pyrazolines (TAPs). Chalcones were prepared via the condensation of substituted acetophenones with aryl-aldehydes under solvent-free conditions. Subsequently, the synthesized chalcones were used for the catalytic synthesis of TAPs via two-component condensation with phenyl hydrazine in refluxing ethanol. VSA is easily prepared by a simple reaction of chlorosulfonic acid and sodium metavanadate of high purity. Compared to conventional procedures, the present protocol offers several advantages such as simplicity of the procedure, appropriate reaction times, high to excellent yields, easily work-up, recoverability, and reusability of the catalyst, and simple purification of the products.
- Nasr-Esfahani, Masoud,Daghaghale, Mona,Taei, Mahbube
-
-
- 13C NMR spectroscopy of heterocycles: 1-phenyl-3-aryl/t-butyl-5-arylpyrazoles
-
A series of chalcones 1-12 were converted to pyrazolines (1Pi-12Pi) by reaction with phenylhydrazine followed by DDQ oxidation to produce the corresponding pyrazoles (1Pz-12Pz). Three 1-phenyl-3-t-butyl-5-arylpyrazoles (13Pz-15Pz) were synthesized using an analogous approach. Molecular modeling studies predicted the 5-aryl group of the pyrazoles for both series to have a torsion angle of 52°-54° whereas the 1-phenyl group was predicted to have 35°-37° torsion angles. The 3-aryl group was predicted to be essentially coplanar (-3°) with the pyrazole system in the first series. 13C NMR data for both series, 1Pz-12Pz and 13Pz-15Pz, were collected in DMSO-d6 at 50°C. A plot of the C4 chemical shifts for 1Pz-12Pz versus Hammet constants for 5-aryl substituents yielded a very good linear correlation (R2=0.96) with a slope of 1.5. The chemical shift data for C4 showed little or no dependence on 3-aryl substituents. The result for 13Pz-15Pz, despite only three points, was consistent with the first series results and yielded a ρ value of 2.0. Distal transmission of substituent effects (5-aryl groups) to C4 of the pyrazole system was reduced by roughly 50-60% of that of the analogous planar isoxazole system, but are not consistent with results for the similarly twisted 4-bromoisoxazoles.
- Hockstedler, Amy N.,Edjah, Beatrice A.,Azhar, Saajid Z.,Mendoza, Hadrian,Brown, Nicole A.,Arrowood, Hayley B.,Clay, Andrew C.,Shah, Anand B.,Duffek, Glenda M.,Cui, Jianmei,Baumstark, Alfons L.
-
p. 125 - 131
(2017/04/14)
-
- Tris(pentafluorophenyl)borane-Catalyzed Acceptorless Dehydrogenation of N-Heterocycles
-
Catalytic acceptorless dehydrogenation is an environmentally benign way to desaturate organic compounds. This process is traditionally accomplished with transition-metal-based catalysts. Herein, a borane-catalyzed, metal-free acceptorless dehydrogenation of saturated N-heterocycles is disclosed. Tris(pentafluorophenyl)borane was identified as a versatile catalyst, which afforded several synthetically important N-heteroarenes in up to quantitative yield. Specifically, the present metal-free catalytic system exhibited a uniquely high tolerance toward sulfur functionalities, and demonstrated superior reactivity in the synthesis of benzothiazoles compared to conventional metal-catalyzed systems. This protocol can thus be regarded as the first example of metal-free acceptorless dehydrogenation in synthetic organic chemistry.
- Kojima, Masahiro,Kanai, Motomu
-
supporting information
p. 12224 - 12227
(2016/10/13)
-
- Nano-TiO2: An efficient and reusable catalyst for the synthesis of 1,3,5-substituted pyrazoles
-
(Formula presented) A Nano-TiO2 is an efficient catalysis for the synthesis of 1,3,5-substituted pyrazoles via condensation of 1,3- diketones and hydrazines. Simple procedure, mild heating, solvent free, high yielding, and easy workup are some advantages of this protocol. The catalyst can be recovered easily and reused many times without significant loss in catalytic activity and selectivity.
- Akbari, Ali,Mirjalili, Bibi Fatemeh
-
p. 119 - 123
(2016/07/15)
-
- Cellulose sulfonic acid as a green, efficient, and reusable catalyst for Nazarov cyclization of unactivated dienones and pyrazoline synthesis
-
A high yielding, eco-friendly and simple procedure for the synthesis of five membered carbo- and heterocycles through cellulose sulfonic acid (CSA) mediated electrocyclization processes has been developed. Cellulose sulfonic acid (CSA) not only was able to induce the cyclization of "unactivated" dienones generating cyclopentenoids; it was also able to trigger the cyclization of α,β-unsaturated hydrazones giving rise to pyrazolines in excellent yields under green reaction conditions. The ease of catalyst recovery and reusability, short reaction time, simple experimental and work-up procedure; compared to the conventional methods, makes this protocol practical, environmentally friendly and economically desirable. The cellulose-SO3H (CSA) was characterized by FT-IR spectroscopy, powder X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses, and catalyst stability was judged by thermogravimetry/differential thermal analysis (TG/DTA). The catalyst can be recycled several times without significant loss of catalytic activity.
- Daneshfar, Zahra,Rostami, Ali
-
p. 104695 - 104707
(2015/12/30)
-
- 1,3,5-Triarylpyrazolines - PH-driven off-on-off molecular logic devices based on a "receptor1-fluorophore-spacer-receptor2" format with internal charge transfer (ICT) and photoinduced electron transfer (PET) mechanisms
-
The excited state photophysical properties of the 1,3,5-triarylpyrazolines 1-4 were studied in methanol and 1:1 (ν/ν) methanol-water, as well as 1:4 (ν/ν) methanol-water and water by fluorescence spectroscopy. The molecules 2-4 incorporate a "receptorsub
- Zammit, Ramon,Pappova, Maria,Zammit, Esther,Gabarretta, John,Magri, David C.
-
p. 199 - 206
(2015/02/05)
-
- Synthesis and anticancer activity of 1,3,5-triaryl-1H-pyrazole
-
Previous studies demonstrated that some pyrazole derivatives could be considered as potential anticancer agents. A series of 1,3,5-triaryl-1H-pyrazole derivatives were prepared by the reaction of phenylhydrazin and different chalcones. The previous classi
- Ghadbeigi, Sajad,Ostad, Seyed Nasser,Shafiee, Abbas,Amini, Mohsen
-
p. 754 - 759
(2015/10/05)
-
- SAR studies of differently functionalized chalcones based hydrazones and their cyclized derivatives as inhibitors of mammalian cathepsin B and cathepsin H
-
Cathepsins have emerged as potential drug targets for melanoma therapy and engrossed attention of researchers for development and evaluation of cysteine cathepsin inhibitors as cancer therapeutics. In this direction, we have designed, synthesized, and ass
- Raghav, Neera,Singh, Mamta
-
supporting information
p. 4233 - 4245
(2014/08/18)
-
- Iron-catalyzed aerobic oxidative aromatization of 1,3,5-trisubstituted pyrazolines
-
A simple and high yielding method for the synthesis of tri-substituted pyrazoles via iron(III) catalyzed aerobic oxidative aromatization of pyrazolines has been reported. The process demonstrates a variety of functional group tolerance.
- Ananthnag, Guddekoppa S.,Adhikari, Adithya,Balakrishna, Maravanji S.
-
p. 240 - 243
(2013/12/04)
-
- Ferrocenyl-contained dendritic-like antioxidants with dihydropyrazole and pyrazole as the core: Investigations into the role of ferrocenyl group and structure-activity relationship on scavenging radical and protecting DNA
-
Eight ferrocenyl and three corresponding phenyl dendritic-like antioxidants with dihydropyrazole or pyrazole as the core were synthesized and their antioxidant abilities to scavenge 2,2′-azinobis(3-ethylbenzothiazoline-6- sulfonate) cationic radical (ABTS+) and to protect DNA against 2,2′-azobis(2-amidinopropane hydrochloride) (AAPH)-induced oxidation were evaluated. It was found that the antioxidant abilities of almost all of the ferrocenyl dendritic-like antioxidants are greater than those of the corresponding phenyl dendritic-like antioxidants remarkably. Moreover, the structure-activity relationships of all these dendritic-like antioxidants were investigated in detail. The quantitative contributions of ferrocenyl group, hydroxyl group, and dihydro-structure in the heterocyclic core to the values of n, napp and n+napp in scavenging ABTS+ and the values of n in protecting DNA against AAPH-induced oxidation were also calculated.
- Li, Pei-Ze,Liu, Zai-Qun
-
p. 9898 - 9905
(2013/10/22)
-
- A convenient and efficient protocol for the synthesis of 1,3,5-triaryl-2-pyrazolines in acetic acid under ultrasound irradiation
-
1,3,5-Triaryl-2-pyrazolines were synthesized in acetic acid in high yields within 60-180 min under ultrasound irradiation at room temperature.
- Lin, Zhi-Ping,Li, Ji-Tai
-
experimental part
p. 267 - 271
(2012/06/18)
-
- Nanocasting, template synthesis, and structural studies on cesium salt of phosphotungstic acid for the synthesis of novel 1,3,5-triaryl-pyrazoline derivatives
-
The elimination of the silica matrix of composites by HF occurred by a two-step reaction deposition of a Cs2.5H0.5PW 12O40 (CsHPW) salt nanocrystal. We used 2D hexagonal SBA-15 silica as a template for the nanof
- Fazaeli, Razieh,Aliyan, Hamid,Tangestaninejad, Shahram,Mohammadi, Esmaeel,Bordbar, Maryam
-
experimental part
p. 237 - 246
(2012/06/30)
-
- Nanocasting, Template Synthesis, and Structural Studies on Cesium Salt of Phosphotungstic Acid for the Synthesis of Novel 1,3,5-Triaryl-pyrazoline Derivatives
-
The elimination of the silica matrix of composites by HF occurred by a two-step reaction deposition of a Cs2.5H0.5PW12O40 (CsHPW) salt nanocrystal. We used 2D hexagonal SBA-15 silica as a template for the nanofabrication of CsHPW nanoparticles. Nanocast CsHPW materials are stable against leaching and colloidization in polar solvents. The catalytic performance of the nanocast CsHPW materials exceeded that of bulk Cs2.5H0.5PW12O40, which is the most active among the acidic HPW salts. A series of novel 1,3,5-triaryl-pyrazoline derivatives were synthesized by the reaction between chalcone and phenylhydrazine in high yield in the presence of CsHPW salt nanocrystals.
- Fazaeli, Razieh,Aliyan, Hamid,Tangestaninejad, Shahram,Mohammadi, Esmaeel,Bordbar, Maryam
-
p. 237 - 246
(2016/04/19)
-
- Solvent free synthesis of substituted-2-pyrazolines using imidazolium based ionic liquid as a solvent and catalyst: A green route approach
-
A series of substituted-2-pyrazolines synthesized using imidazolium based ionic liquid, 1,2-[bis-(3'-methyl-imidazolium-hydrogen sulphate)]-ethane as a solvent and catalyst, by reacting chalcones react with phenyl hydrazine. The compounds were characteriz
- Karthikeyan,Kumar, S. Senthil,Jagadeesh, Rajenahally V.,Bhagat, Pundlik Rambhau
-
experimental part
p. 1351 - 1353
(2012/10/07)
-
- Antimicrobial, analgesic, DPPH scavenging activities and molecular docking study of some 1,3,5-triaryl-2-pyrazolines
-
A series of 1,3,5-triaryl-2-pyrazolines 2a-g were synthesized by the reaction of 4,40-disubstituted chalcone with phenyl hydrazine. All these compounds were characterized by NMR, IR and mass spectral and single crystal XRD data. All the synthesized produc
- Samshuddin, Seranthimata,Narayana, Badiadka,Sarojini, Balladka Kunhanna,Raj, Chenna Govindaraju Darshan,Khan, Mahmud Tareq Hassan,Yathirajan, Hemmige S.,Raghavendra, Ramappa
-
p. 2012 - 2022,11
(2020/07/30)
-
- Tungstophosphoric acid supported on highly organosoluble polyamide (PW 12/PA): Highly efficient catalysts for the synthesis of novel 1,3,5-triaryl-2-pyrazoline derivatives
-
A novel compound constructed from polyoxometalate (H3PW 12O40, PW12) and poly(amidoamine) (PA) was prepared at room temperature in an aqueous solution by an impregnation method. A series of novel 1,3,5-triaryl-2-pyrazoline derivatives was synthesized by the reaction between chalcone and phenylhydrazine in the presence of the title compound, PW12/PA, in high yields. The structures of the compounds obtained were determined by IR and 1H NMR spectra.
- Fazaeli, Razieh,Aliyan, Hamid,Mallakpour, Shadpour,Rafiee, Zahra,Bordbar, Maryam
-
experimental part
p. 582 - 588
(2012/01/06)
-
- Determination of the absolute configuration of 1,3,5-triphenyl-4,5- dihydropyrazole enantiomers by a combination of VCD, ECD measurements, and theoretical calculations
-
The enantiomers of 1,3,5-triphenyl-4,5-dihydropyrazole (an intense blue fluorescent compound) have been separated for the first time and their absolute configuration was established by a combination of VCD and ECD measurements and theoretical calculations
- Vanthuyne, Nicolas,Roussel, Christian,Naubron, Jean-Valre,Jagerovic, Nadine,Lazaro, Paula Morales,Alkorta, Ibon,Elguero, Jose
-
experimental part
p. 1120 - 1124
(2011/10/05)
-
- Thiocyanation on n-benzene rings of 1,3,5-trisubstituted pyrazolines with oxone
-
An efficient aromatic thiocyanation of 1,3,5-trisubstituted pyrazolines occurred regioselectively at the para position of N-benzene rings using ammonium thiocyanate as a thiocyanation reagent and oxone as an oxidant.
- Wu, Guaili,Liang, Ruirui,Chen, Yongjiang,Wu, Longmin
-
experimental part
p. 129 - 134
(2010/03/24)
-
- Mechanically activated synthesis of 1,3,5-triaryl-2-pyrazolines by high speed ball milling
-
An efficient mechanically activated solvent-free synthesis of 1,3,5-triaryl-2-pyrazolines from chalcones and phenylhydrazines using high speed ball milling is described. This method has notable advantages in terms of good yield, short reaction time and ne
- Zhu, Xingyi,Li, Zhenhua,Jin, Can,Xu, Li,Wu, Qianqian,Su, Weike
-
experimental part
p. 163 - 165
(2010/04/22)
-
- New reaction of photoaromatization of aryl- and hetarylpyrazolines
-
Aryl- and hetarylpyrazolines smoothly undergo photoaromatization under irradiation with the visible light (λ > 400 nm) in the presence of carbon tetrachloride. The reaction is accompanied by an increase in the acidity of the medium and a change in the fluorescence. The structure of pyrazoline and solvent considerably affect the photoaromatization rate. The mechanism of the reaction was proposed, which agrees with the experimental data.
- Traven,Ivanov
-
experimental part
p. 1063 - 1069
(2009/09/05)
-
- Differential tuning of the electron transfer parameters in 1,3,5-triarylpyrazolines: A rational design approach for optimizing the contrast ratio of fluorescent probes
-
A large class of cation-responsive fluorescent sensors utilizes a donor-spacer-acceptor (D-A) molecular framework that can modulate the fluorescence emission intensity through a fast photoinduced intramolecular electron transfer (PET) process. The emissio
- Cody, John,Mandal, Subrata,Yang, Liuchun,Fahrni, Christoph J.
-
supporting information; experimental part
p. 13023 - 13032
(2009/03/12)
-
- Novel synthesis of 1,3,5-trisubstituted 2-pyrazolines promoted by chlorotrimethylsilane
-
1,3,5-Trisubstituted-2-pyrazolines were effectively synthesised by utilising chlorotrimethylsilane as an efficient promoter in the cyclisation addition of Phenylhydrazine to chalcones under nitrogen in acetonitrile. The clean, mild reaction conditions, high yields and a simple workup of target compounds were attractive features of the reaction which enables a facile preparative procedure for building the pyrazoline ring.
- Xie, Zengyang,Bian, Xiaoqin,Geng, Xin,Li, Shuangshuang,Wang, Cunde
-
-
- Synthesis of some new bioactive 1-N-subtituted 3,5-diaryl-2-pyrazolines
-
A group of four series (A-D) of 22 new bioactive 1-N-acid substituted 3, 5-diphenyl-2-pyrazolines were synthesized by cyclization of variably substituted chalcones and simple or substituted phenyl hydrazine and / or semicarbazide, using acetic acid as a s
- Khan, Sadaf Sadiq,Hasan, Aurangzeb
-
p. 131 - 138
(2008/02/12)
-
- Iodine-mediated synthesis of 2-arylbenzoxazoles, 2-arylbenzimidazoles, and 1,3,5-trisubstituted pyrazoles
-
2-Arylbenzoxazoles and 2-arylbenzimidazoles were synthesized by the reaction of aldehydes with 2-aminophenol and O-phenylenediamines in the presence of iodine. 1,3,5-Trisubstituted pyrazoles were synthesized from chalcones and hydrazines in the presence o
- Ponnala, Shashikanth,Prasad Sahu, Devi
-
p. 2189 - 2194
(2007/10/03)
-
- Aqueous N-heterocyclization of primary amines and hydrazines with dihalides: Microwave-assisted syntheses of N-azacycloalkanes, isoindole, pyrazole, pyrazolidine, and phthalazine derivatives
-
The synthesis of nitrogen-containing heterocycles from alkyl dihalides (ditosylates) and primary amines and hydrazines via a simple and efficient cyclocondensation in an alkaline aqueous medium that occurs under microwave irradiation is described. This improved greener synthetic methodology provides a simple and straightforward one-pot approach to the synthesis of a variety of heterocycles, such as substituted azetidines, pyrrolidines, piperidines, azepanes, N-substituted 2,3-dihydro-1H-isoindoles, 4,5-dihydropyrazoles, pyrazolidines, and 1,2-dihydrophthalazines.
- Ju, Yuhong,Varma, Rajender S.
-
p. 135 - 141
(2007/10/03)
-
- KHSO4 · H2O/SiO2-catalyzed, one-pot, solvent-free synthesis of pyrazolines, tetrahydrocarbozoles and indoles using microwave irradiation
-
A new high-yielding, operationally simple, solvent-free, and mild method for preparation of pyrazolines, tetrahydrocarbazoles, and indoles has been developed using KHSO4 · H2O impregnated on SiO 2. The reactions have been probed under microwave irradiation (MWI), and ultrasonic and thermal conditions, employing different solid supports. The data revealed that KHSO4 · H2O impregnated on SiO2 under MWI provides the best yields in a shorter time under solvent-free reaction conditions. Copyright Taylor & Francis Group, LLC.
- Kapoor, Kamal K.,Ganai, Bilal A.,Kumar, Satish,Andotra, Charanjeet S.
-
p. 2727 - 2735
(2007/10/03)
-
- A modified and convenient method for the preparation of N-phenylpyrazoline derivatives
-
Ten new N-phenylpyrazoline derivatives have been synthesized in high yields by condensation of chalcones with phenylhydrazine in the presence of potassium carbonate in reflux conditions. The workup is simple and involves treatment with ice-cold water. As compared with the previous method a considerable increase in the reaction rate with better yields has been observed.
- Safaei-Ghomi,Bamoniri,Soltanian-Telkabadi
-
p. 892 - 896
(2008/02/10)
-
- Microwave-assisted cyclocondensation of hydrazine derivatives with alkyl dihalides or ditosylates in aqueous media: Syntheses of pyrazole, pyrazolidine and phthalazine derivatives
-
Direct syntheses of 4,5-dihydro-pyrazole, pyrazolidine, and 1,2-dihydro-phthalazine derivatives via double-alkylation of hydrazines by alkyl dihalides or ditosylates were accomplished in aqueous media under microwave irradiation conditions; the environmen
- Ju, Yuhong,Varma, Rajender S.
-
p. 6011 - 6014
(2007/10/03)
-
- Silica-supported synthesis of some 1,3,5-trisubstituted 2-pyrazolines under solvent-free and microwave irradiation conditions
-
A simple method for the synthesis of 2-pyrazolines is described which occurs on silica surface under solvent-free conditions within 110-180 sec using microwave irradiation. The results obtained indicate that the use of silica gel as a support in pyrazolin
- Azarifar, Davood,Maleki, Behrooz
-
p. 157 - 159
(2007/10/03)
-
- Synthesis of pyrazoline and isoxazoline in triethanolamine medium
-
Reactions of chalcones 1a-u with phenylhydrazine and hydrazine hydrate give pyrazolines 2a-u and with hydroxylamine hydrochloride yield isoxazolines 3a-c in triethanolamine medium. The structures of products are established by melting points, chemical studies and spectral data (IR and 1HNMR).
- Agrawal, Nitin N.,Soni
-
p. 2700 - 2701
(2007/10/03)
-
- Solid-phase synthesis of pyrazolines and isoxazolines with sodium benzenesulfinate as a traceless linker
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(Matrix presented) The preparation of pyrazoline and isoxazoline derivatives with traceless solid-phase sulfone linker strategy is described. Key steps involved in the solid-phase synthetic procedure include (i) sulfinate S-alkylation, (ii) sulfone anion alkylation, (iii) γ-hydroxy sulfone → γ-ketosulfone oxidation, and (iv) traceless product release via elimination-cyclization. A library of 12 pyrazolines and isoxazolines was synthesized.
- Chen,Lam, Yulin,Lai, Yee-Hing
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p. 1067 - 1069
(2007/10/03)
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- Transformations of mono- and bisphenylhydrazones of aliphatic-aromatic 1,5-diketones under the conditions of the fischer reaction
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The mono- and bisphenylhydrazones of 3-R-1,5-diphenylpentane-1,5-diones were obtained, and their transformations in the Fischer indole synthesis under various conditions were studied. It was shown that 4-R-2,6-diphenylpyridines, 2-phenylindole, and 5-R-1,-3-diphenyl-Δ2-pyrazolines are formed as the main products in addition to the 3-R-1-phenyl-3-(2-phenyl-3-indolyl)propan-1-ones or their phenylhydrazones produced as a result of indolization. The ways of formation of these compounds are discussed. Some transformations of the obtained ketones were studied.
- Moskovkina
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p. 1190 - 1199
(2007/10/03)
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- Automated parallel synthesis of chalcone-based screening libraries
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Using a variety of condensation and cyclization reactions, nine combinatorial arrays of individual chalcone derivatives, over 74,000 in all, were produced in 50 μM quantities. The ease with which a broad range of diversity can be fabricated around a single molecular motif using automated parallel solution phase synthesis has been demonstrated.
- Powers, David G.,Casebier, David S.,Fokas, Demosthenes,Ryan, William J.,Troth, Jonah R.,Coffen, David L.
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p. 4085 - 4096
(2007/10/03)
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- CHLORAMINE-T IN HETEROCYCLIC SYNTHESIS; A SIMPLE PROCEDURE FOR THE GENERATION OF NITRILIMINES AND ITS APPLICATION TO THE SYNTHESIS OF PYRAZOLINES
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A new method of generating nitrilimines is described.It involves the reaction of aromatic as well as aliphatic aldehyde hydrazones with chloramine-T.In the presence of olefins pyrazolines are obtained in good yield.
- Rai, Lokanatha,Hassner, Alfred
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p. 2799 - 2808
(2007/10/02)
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- REACTION OF SINGLET OXYGEN WITH 2-PYRAZOLINE: IMPLICATION FOR CATION RADICAL - SUPEROXIDE ION PAIR INTERMEDIATE
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Kinetic studies on photosensitized oxygenation of 1,3,5-triaryl-2-pyrazolines show that an electron-transfer from the pyrazoline to singlet oxygen may take place to give a cation radical and superoxide ion pair.The reaction of pyrazoline cation radicals with superoxide ion shows the same product distribution with singlet oxygenation.
- Akasaka, Takeshi,Nakagawa, Masaru,Nomura, Yuko,Sato, Rikiya,Someno, Kazuo,Ando, Wataru
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p. 3807 - 3812
(2007/10/02)
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- REACTION OF 1-METHYLURACIL WITH PHENYLBENZHYDRAZONOYL CHLORIDE
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The ambident anion of 1-methyluracil gives with phenylbenzhydrazonoyl chloride, depending on the conditions, the N-acylation product (polar solvent, room temperature), or the O-acylation product (nonpolar solvent, heating), which rearranges to a cytosine derivative.Convenient methods have been developed for the preparation of 6-methyl-1,3-diphenyl-5,6-dihydro-5-oxopyrimidotriazolium chloride, a fluorescent derivative of 1-methyluracil, from the N-acylation product, and for the rapid base cleavage of the uracil ring under very mild conditions.
- Chernyshova, N. B.,Shibaev, V. N.
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p. 532 - 538
(2007/10/02)
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- A CARBON-13 AND NITROGEN-15 ISOTOPIC LABELLING STUDY OF INTERMEDIATES AND BY-PRODUCTS IN THE REACTION OF CHALCONE AND PHENYLHYDRAZINE TO GIVE 1,3,5-TRIPHENYL-2-PYRAZOLINE
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The formation of 1,3,5-triphenyl-2-pyrazoline 7 from chalcone and phenylhydrazine via 1,4-addition followed by an allowed 5-endo-trig cyclisation has been demonstrated by (13)C and (15)N labelling in time resolved (13)C NMR spectroscopy.
- Kenny, Peter W.,Robinson, Michael J. T.
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p. 6277 - 6280
(2007/10/02)
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- ONE-ELECTRON OXIDATION OF 1,3,5-TRIARYL-2-PYRAZOLINES BY ANTIMONY PENTACHLORIDE
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Upon reaction of 1,3,5-triphenyl- and 1,3,5-triphenyl-5-methyl-2-pyrazolines with antimony pentachloride in acetonitrile they undergo oxidation to cation radicals, which subsequently undergo rapid dimerization at the para positions of the N-phenyl groups.
- Morkovnik, A. S.,Okhlobystin, O. Yu.
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p. 461 - 464
(2007/10/02)
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