93330-77-9Relevant articles and documents
Iron(III) phthalocyanine chloride-catalyzed oxidation-aromatization of α,β-unsaturated ketones with hydrazine hydrate: Synthesis of 3,5-disubstituted 1H-pyrazoles
Zhao, Junlong,Qiu, Jun,Gou, Xiaofeng,Hua, Chengwen,Chen, Bang
, p. 571 - 578 (2016/04/20)
We have developed an iron(III) phthalocyanine chloride-catalyzed oxidation-aromatization of α,β-unsaturated ketones with hydrazine hydrate. Various 3,5-disubstituted 1H-pyrazoles were obtained in good to excellent yields. This method offers several advantages, including room-temperature conditions, short reaction time, high yields, simple work-up procedure, and use of air as an oxidant. The catalyst can be recovered and reused five times without loss of activity.
Sulphur promoted C(sp3)-C(sp2) cross dehydrogenative cyclisation of acetophenone hydrazones with aldehydes: Efficient synthesis of 3,4,5-trisubstituted 1H-pyrazoles
Vanjari, Rajeshwer,Guntreddi, Tirumaleswararao,Kumar, Saurabh,Singh, Krishna Nand
supporting information, p. 366 - 369 (2015/01/09)
A novel strategy for the cross dehydrogenative coupling (CDC) of acetophenone hydrazones and aldehydes has been developed for the synthesis of highly substituted pyrazoles. This work, for the first time, uses elemental sulfur as a promoter as well as a hydrogen acceptor in effecting the Csp3-Csp2 bond formation via C-H activation. This journal is
Transition-Metal-Free N-Arylation of Pyrazoles with Diaryliodonium Salts
Gonda, Zsombor,Novák, Zoltán
, p. 16801 - 16806 (2015/11/16)
A new synthetic method was developed for the N-arylation of pyrazoles using diaryliodonium salts. The transformation does not require any transition-metal catalyst and provides the desired N-arylpyrazoles rapidly under mild reaction condition in the presence of aqueous ammonia solution as a mild base without the use of inert atmosphere. The chemoselectivity of unsymmetric diaryliodonium salts was also explored with large number of examples.
Preparation of 3,5-disubstituted pyrazoles and isoxazoles from terminal alkynes, aldehydes, hydrazines, and hydroxylamine
Harigae, Ryo,Moriyama, Katsuhiko,Togo, Hideo
, p. 2049 - 2058 (2014/04/03)
The reaction of terminal alkynes with n-BuLi, and then with aldehydes, followed by the treatment with molecular iodine, and subsequently hydrazines or hydroxylamine provided the corresponding 3,5-disubstituted pyrazoles or isoxazoles in good yields with high regioselectivity, through the formations of propargyl secondary alkoxides and α-alkynyl ketones. The present reactions are one-pot preparation of 3,5-disubstituted pyrazoles from terminal alkynes, aldehydes, molecular iodine, and hydrazines, and 3,5-disubstituted isoxazoles from terminal alkynes, aldehydes, molecular iodine, and hydroxylamine.
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 (2013/08/23)
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
Synthesis, spectroscopic characterization and quantum chemical computational studies on 1-acetyl-3,5-di(4-methylphenyl)-1H-pyrazole
Inkaya, Ersin,Din?er, Muharrem,Korkusuz, Elif,Yildirim, Ismail,Büyükgüng?r, Orhan
, p. 133 - 139 (2013/01/15)
The pyrazole compound 1-acetyl-3,5-di(4-methylphenyl)-1H-pyrazole, (C 19H18N2O), was characterized by X-ray single crystal diffraction technique, IR-NMR spectroscopy and quantum chemical computational methods as both experimental and theoretically. The compound crystallizes in the monoclinic space group C 2/c with a = 32.5334 (1) ?, b = 5.8060 (1) ?, c = 23.6519 (8) ?, β = 134.572 (2)°, and Z = 8. The molecular geometry was also optimized using the Hartree-Fock (HF) and density functional theory (DFT/B3LYP) methods with the 6-311G(d,p) basis set and compared with the experimental data. To determine conformational flexibility, molecular energy profile of the tittle compound was obtained by semi-empirical (AM1) with respect to selected degree of torsional freedom, which was varied from -180° to +180° in steps 10°. From the optimized geometry of the molecule, vibrational frequencies, gauge-independent atomic orbital (GIAO) 1H and 13C NMR chemical shift values, molecular electrostatic potential (MEP) distribution, non-linear optical properties, frontier molecular orbitals (FMOs) of the title compound have been calculated in the ground state theoretically. The theoretical result showed good agreement with the experimental values.
A facile and convenient approach to the synthesis of 3,5-diaryl-1H- pyrazoles
Nikpour, Farzad,Beigvand, Mahdi
experimental part, p. 821 - 824 (2009/09/24)
A simple and convenient one-pot synthesis route is described for the synthesis of 3,5-diaryl-1H-pyrazoles in short reaction times from the reaction of α-epoxyketones with semicarbazide hydrochloride under mild conditions.
New one step synthesis of 3,5-disubstituted pyrazoles under microwave irradiation and classical heating
Outirite, Moha,Lebrini, Mounim,Lagrenee, Michel,Bentiss, Fouad
, p. 503 - 505 (2008/09/20)
(Chemical Equation Presented) A convenient one pot procedure for the synthesis of 3,5-disubstituted pyrazoles by condensation of chalcones, hydrazine hydrate and sulfur in ethanol under microwave irradiation and conventional heating method is reported. The hydrogen sulfide is produced during the reaction. The pyrazoles are obtained in good yields and excellent state of purity. The structures of new compounds were confirmed by IR, 1H, and 13C NMR, MS and elemental analysis.
Monoamine oxidase isoform-dependent tautomeric influence in the recognition of 3,5-diaryl pyrazole inhibitors
Chimenti, Franco,Fioravanti, Rossella,Bolasco, Adriana,Manna, Fedele,Chimenti, Paola,Secci, Daniela,Befani, Olivia,Turini, Paola,Ortuso, Francesco,Alcaro, Stefano
, p. 425 - 428 (2007/10/03)
A series of 3,5-diaryl pyrazoles were prepared and assayed for their ability to inhibit reversibly monoamine oxidase-A (MAO-A) and monoamine oxidase B (MAO-B). Several compounds show inhibitory activity with concentration values in the nanomolar range. A computational work was carried out on the two most selective inhibitors that have tautomeric pyrazole forms. The binding free energies of these compounds for each MAO isoform were influenced by the tautomeric equilibria.
