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81.
V. Ya. Sosnovskikh M. A. Barabanov B. I. Usachev R. A. Irgashev V. S. Moshkin 《Russian Chemical Bulletin》2005,54(12):2846-2850
Condensation of 4-acetyl-5-hydroxy-3-methyl-1-phenylpyrazole with RFCO2Et (RF = CF2H, CF3) in the presence of LiH affords 4-di(tri)fluoroacetoacetyl-5-hydroxy-3-methyl-1-phenylpyrazoles from which 6-di(tri)fluoromethyl-and
5-di(tri)fluoroacetyl-3-methyl-1-phenylpyrano[2,3-c]pyrazol-4(1H)-ones were synthesized. The reactions of pyrano-pyrazoles with hydrazine hydrate, ethyl mercaptoacetate, or aromatic amines
proceed at the C(6) atom with pyrone ring opening and formation of aminoenones, pyrazoles, or thiophenes with the 5-hydroxy-3-methyl-1-phenyl-4-pyrazolyl
fragment.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2750–2754, December, 2005. 相似文献
82.
Debprasad Patra Poulami Pattanayak Jahar Lal Pratihar Surajit Chattopadhyay 《Polyhedron》2007,26(18):5484-5490
The reactions of HL 1 [where HL is 1N-(2-pyridyl-2-methyl)-2-arylazoaniline and is formulated as ArN = NC6H4N(H)(CH2C5H4N); Ar = C6H5 (for HL1) or p-MeC6H4 (for HL2) or p-ClC6H4 (for HL3)] with K2PtCl4 and Co(ClO4)3 · 6H2O afforded the (L)PtCl and [(L)2Co]ClO4 complexes, respectively. The HL ligands bind the platinum(II) and cobalt(III) centres in a tridentate (N,N,N) fashion, forming new diazoketiminato chelates upon dissociating the amino proton. The X-ray structures of (L3)PtCl and [(L3)2Co]ClO4 were determined. Redox properties of the new complexes have been examined. 相似文献
83.
固定有四硫富瓦烯.四氰基奎诺二甲烷的杂聚吡咯膜微葡萄糖电极 总被引:1,自引:0,他引:1
铂比互铂化处理后,形成疏松,粗糙的表面,将四硫富瓦烯-四氰基奎诺二甲烷导电有机盐入到铂化的铂黑微粒中。将3-羰基丁酸吡咯与吡咯按适当的比例在其表面用电化学聚合方法,将葡萄糖氧化酶固定于聚合形成的杂聚膜中制成微酶电极。该微酶电极测定时几乎不受氧分压影响,灵敏度高,响应快。 相似文献
84.
We have developed a method for obtaining 2-substituted 3-amino-6,6-dimethyl-5,6-dihydro-8H-pyrano[4′,3′:4,5]-and 5,6,7,8-tetrahydrobenzo[b]thieno[2,3-d]pyrimidin-4(3H)-ones,
converted by deamination to the corresponding dihydropyranothieno-3H-pyrimidinones.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 441–444, March, 2006. 相似文献
85.
Khalid Mohammed Khan Ghulam Murtaza MaharviSafdar Hayat Zia-UllahM. Iqbal Choudhary Atta-ur-Rahman 《Tetrahedron》2003,59(29):5549-5554
Treatment of aromatic carboxylic acids and substituted toluenes with a mixture of sodium bromate and sodium hydrogen sulfite in a two-phase system gave the corresponding esters in good yield. The intermediate α-brominated toluene was formed by the in situ generated hypobromous acid. The α-bromotoluene underwent an intermolecular nucleophilic substitution reaction with aromatic carboxylic acids present in the reaction mixture to afford the corresponding esters. 相似文献
86.
Studies on Hydroiodination and Deconjugation of 5—Aryloxy—(thiophenyl)—3—pentyn—2—one 总被引:1,自引:0,他引:1
One-pot hydroiodination and deconjugation of 5-aryloxy(or thiophenyl)-3-pentyn-2-one with a reagent system of sodium iodide/trimethylsilyl chloride/water in acetonitrile at 25℃ have been described.The plasuible mechanism was discussed.The reaction provided a simple and useful method for the preparation of (Z)-β-substituted β,γ-enones and (Z)-β-substituted α,β-unsaturated ketones. 相似文献
87.
Bis(cyclopentadienyl)methane-bridged Dinuclear Complexes, V[1]. – Heteronuclear Co/Rh-, Co/Ir-, Rh/Ir-, and Ti/Ir Complexes with the Bis(cyclopentadienyl)methane Dianion as Bridging Ligand* The lithium and sodium salts of the [C5H5CH2C5H4]- anion, 1 and 2 , react with [Co(CO)4I], [Rh(CO)2Cl]2, and [Ir(CO)3Cl]n to give predominantly the mononuclear complexes [(C5H5-CH2C5H4)M(CO)2] ( 3, 5, 7 ) together with small amounts of the dinuclear compounds [CH2(C5H4)2][M(CO)2]2 ( 4, 6, 8 ). The 1H- and 13C-NMR spectra of 3, 5 , and 7 prove that the CH2C5H5 substituent is linked to the π-bonded ring in two isomeric forms. Metalation of 5 and 7 with nBuLi affords the lithiated derivatives 9 and 10 from which on reaction with [Co(CO)4I], [Rh(CO)2Cl]2, and [C5H5TiCl3] the heteronuclear complexes [CH2(C5H4)2][M(CO)2][M′(CO)2] ( 11–13 ) and [CH2(C5H4)2]-[Ir(CO)2][C5H5TiCl2] ( 17 ) are obtained. Photolysis of 11 and 12 leads almost quantitatively to the formation of the CO-bridged compounds [CH2(C5H4)2][M(CO)(μ-CO)M′(CO)] ( 14, 15 ). According to an X-ray crystal structure analysis the Co/Rh complex 14 is isostructural to [CH2(C5H4)2][Rh2(CO)2(μ-CO)] ( 16 ). 相似文献
88.
Bunichiro Yamada Shinji Tagashira Shuzo Aoki 《Journal of polymer science. Part A, Polymer chemistry》1994,32(14):2745-2754
The dimerization of methyl methacrylate, ethyl methacrylate, methacrylonitrile, and α-methylstyrene to 2-substituted-1-allylic compounds [CH2?C(X)CH2C(CH3)2X] (X = COOR, C6H5, or CN), and methyl α-ethylacrylate to a 3-substituted-2-allylic compound [CH3CH?C(COOCH3)CH2C(CH3)(C2H5) COOCH3] was carried out by catalytic chain transfer using benzylbis (dimethylglyoximato) (pyridine) cobalt (III). These dimers were then used as addition-fragmentation chain transfer agents in the polymerizations of methyl methacrylate and styrene at 800C or above. Cross-dimers from methacrylic ester-α-methylstyrene and methacrylonitrile-α-methylstyrene mixtures were similarly prepared. Except for those from methyl α-ethylacrylate and methacrylonitrile, all the dimers participated in the addition-fragmentation and the copolymerization to different extents. The dimer of methyl α-ethylacrylate was actually inactive during the styrene and methyl methacrylate polymerizations. The methacrylonitrile dimer was primarily incorporated in the polymer chain through copolymerization. Among the dimer and the cross-dimers from α-methylstyrene with the other monomers, those bearing the α-methylstyrene moiety in the α-substituent [CH2?C(X)CH2C(CH3)2C6H5, X?COOCH3, COOC2H5, and CN] are noted as highly reactive chain transfer agents. © 1994 John Wiley & Sons, Inc. 相似文献
89.
Engineering a Cu‐MOF Nano‐Catalyst by using Post‐Synthetic Modification for the Preparation of 5‐Substituted 1H‐Tetrazoles 下载免费PDF全文
A new nano scale Cu‐MOF has been obtained via post‐synthetic metalation by immersing a Zn‐MOF as a template in DMF solutions of copper(II) salts. The Cu‐MOF serves as recyclable nano‐catalyst for the preparation of 5‐substituted 1H‐tetrazoles via [3 + 2] cycloaddition reaction of various nitriles and sodium azide in a green medium (PEG). The post‐synthetic metalated MOF were characterized by FT‐IR spectroscopy, powder X‐ray diffraction (PXRD), atomic absorption spectroscopy (AAS), and energy dispersive X‐ray spectroscopy (EDX) techniques. The morphology and size of the nano‐catalyst were determined by field emission scanning electron microscopy (FE‐SEM). 相似文献
90.
One‐pot synthesis of 1‐ and 5‐substituted 1H‐tetrazoles using 1,4‐dihydroxyanthraquinone–copper(II) supported on superparamagnetic Fe3O4@SiO2 magnetic porous nanospheres as a recyclable catalyst 下载免费PDF全文
An effective one‐pot, convenient process for the synthesis of 1‐ and 5‐substituted 1H‐tetrazoles from nitriles and amines is described using1,4‐dihydroxyanthraquinone–copper(II) supported on Fe3O4@SiO2 magnetic porous nanospheres as a novel recyclable catalyst. The application of this catalyst allows the synthesis of a variety of tetrazoles in good to excellent yields. The preparation of the magnetic nanocatalyst with core–shell structure is presented by using nano‐Fe3O4 as the core, tetraethoxysilane as the silica source and poly(vinyl alcohol) as the surfactant, and then Fe3O4@SiO2 was coated with 1,4‐dihydroxyanthraquinone–copper(II) nanoparticles. The new catalyst was characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, dynamic light scattering, thermogravimetric analysis, vibration sample magnetometry, X‐ray photoelectron spectroscopy, nitrogen adsorption–desorption isotherm analysis and inductively coupled plasma analysis. This new procedure offers several advantages such as short reaction times, excellent yields, operational simplicity, practicability and applicability to various substrates and absence of any tedious workup or purification. In addition, the excellent catalytic performance, thermal stability and separation of the catalyst make it a good heterogeneous system and a useful alternative to other heterogeneous catalysts. Also, the catalyst could be magnetically separated and reused six times without significant loss of catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献