2515-60-8Relevant academic research and scientific papers
13C NMR spectroscopy of heterocycles: 1-phenyl-3-aryl/t-butyl-5-arylpyrazoles
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)
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.
Catalytic Synthesis of Chalcones and Pyrazolines Using Nanorod Vanadatesulfuric Acid: An Efficient and Reusable Catalyst
Nasr-Esfahani, Masoud,Daghaghale, Mona,Taei, Mahbube
, p. 17 - 24 (2017/01/17)
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.
SAR studies of differently functionalized chalcones based hydrazones and their cyclized derivatives as inhibitors of mammalian cathepsin B and cathepsin H
Raghav, Neera,Singh, Mamta
supporting information, p. 4233 - 4245 (2014/08/18)
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
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
Fazaeli, Razieh,Aliyan, Hamid,Mallakpour, Shadpour,Rafiee, Zahra,Bordbar, Maryam
, p. 582 - 588 (2012/01/06)
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.
Novel synthesis of 1,3,5-trisubstituted 2-pyrazolines promoted by chlorotrimethylsilane
Xie, Zengyang,Bian, Xiaoqin,Geng, Xin,Li, Shuangshuang,Wang, Cunde
, p. 52 - 54 (2008/09/19)
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.
A modified and convenient method for the preparation of N-phenylpyrazoline derivatives
Safaei-Ghomi,Bamoniri,Soltanian-Telkabadi
, p. 892 - 896 (2008/02/10)
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.
Solid-phase synthesis of pyrazolines and isoxazolines with sodium benzenesulfinate as a traceless linker
Chen,Lam, Yulin,Lai, Yee-Hing
, p. 1067 - 1069 (2007/10/03)
(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.
