1602-00-2Relevant academic research and scientific papers
Mesoporous manganese oxide catalyzed aerobic oxidative coupling of anilines to aromatic azo compounds
Dutta, Biswanath,Biswas, Sourav,Sharma, Vinit,Savage, Nancy Ortins,Alpay, S. Pamir,Suib, Steven L.
, p. 2171 - 2175 (2016)
Herein we introduce an environmentally friendly approach to the synthesis of symmetrical and asymmetrical aromatic azo compounds by using air as the sole oxidant under mild reaction conditions in the presence of cost-effective and reusable mesoporous manganese oxide materials.
Liquid Crystalline Solvents as Mechanistic Probes. 11. The Syn -> Anti Thermal Isomerization Mechanism of Some Low-"Bipolarity" Azobenzenes
Otruba, Joseph P.,Weiss, Richard G.
, p. 3448 - 3453 (1983)
The effects of solvent order on the syn -> anti isomerization rates of 15 azobenzenes have been investigated.The activation parameters determined in a cholesteric phase consisting of a 35/65 (w/w) mixture of cholesteryl chloride/cholesteryl nonanoate and in several other solvents are more consistent with an isomerization mechanism which proceeds via inversion (in plane) rather than rotation (out of plane).A correction of our previously reported data is given.The anomalous behavior of the isomerization mechanism of di-ortho-methylated azobenzenes is demonstrated by means of isokinetic plots.
COOPERATION OF ARYLIMINODIMAGNESIUM MOLECULES: DEOXYGENATION OF AZOXYARENES BY MONO- AND BIFUNCTIONAL REAGENTS IN COMPARISON WITH THAT BY PHOSPHORUS(III) REAGENTS
Okubo, Masao,Inatomi, Yoshito,Eguchi, Izumi,Nishida, Hiroshi,Gotoh, Seiji,Matsuo, Koji
, p. 18 - 23 (1994)
Reaction of aryliminodimagnesium with nitrobenzene (Ar1NO2) in tetrahydrofuran (THF) gives unsymmetrical (unsym) azoxybenzene, which is deoxygenated to give unsym-azobenzene.The reaction is utilized for the independent prepar
Aryliminodimagnesium Reagents. XII. The Distribution of Products in the Condensation with Nitrobenzothiazoles. Reduction of Electron-Donating Ability of Reagent by the Interaction with Thiazolyl Group
Okubo, Masao,Asao, Keiko,Hyakutake, Hiroyuki
, p. 3781 - 3784 (1987)
The 4-, 5-, 6-, and 7-nitro derivatives of benzothiazole condense with ArN(MgBr)2 giving unsym-azoxy and -azo products.The product distribution indicated the mild nature of the reaction, and could be explained in terms of a reduced electron-donating ability of the reagent due to an interaction with thiazolyl group.
Synthesis, in vitro and in vivo anticancer activities of novel 4-substituted 1,2-bis(4-chlorophenyl)-pyrazolidine-3,5-dione derivatives
Zhang, Xu-Yao,Gu, Yi-Fei,Chen, Ting,Yang, Dong-Xiao,Wang, Xi-Xin,Jiang, Bai-Ling,Shao, Kun-Peng,Zhao, Wen,Wang, Cong,Wang, Jun-Wei,Zhang, Qiu-Rong,Liu, Hong-Min
, p. 1781 - 1786 (2015)
To develop potent and selective anticancer agents, a series of novel 4-substituted 1,2-bis(4-chlorophenyl)-pyrazolidine-3,5-dione derivatives were designed and synthesized. All the compounds were evaluated for their antiproliferative activities against a panel of four human cancer cell lines. Among them, compound 4u is the most potent, exhibiting IC50 values ranging from 5.1 to 10.1 μM. Flow cytometry and western blot analyses revealed that treatment of MGC-803 cells with compound 4u induces early cellular apoptosis via activation of caspases-9/3. Furthermore, compound 4u effectively reduced the tumor growth exhibited by human gastric cancer cells in vivo without obvious adverse side effects. Our findings indicate that compound 4u may serve as a lead compound to target solid tumors.
Interactions of chloroanilines with natural and ion exchanged montmorillonites
Kowalska, Maria,Cocke, David L.
, p. 547 - 552 (1998)
The interaction of 4-chloroaniline, 2,3- and 2,5-dichloroanilines with K-10 montmorillonite, and Cu2+-, Fe3+- and Al3+ ion exchanged montmorillonites have been investigated using GC/MS detection of the reaction prodccts in
Synthesis and crystal structure of the silver complexes [PPh4]2[Ag4Cl4 (ClC6H4N3C6H4Cl)2], [Et4N][Ag2(tolyl-N5-tolyl)3] ·2THF and [(n-Bu)4N]3 [Ag3I6]and about the reaction of [Ag(ClC6H4N3C6H4Cl)]2 and [Ag(tolyl-N5-tolyl)] 2 with iodine
Barboza Da Silva, Carlos F.,Schwarz, Simon,Mestres, Montserrat Galceran,Straehle, Joachim
, p. 2231 - 2236 (2004)
The silver triazenido complex [PPh4]2[Ag 4Cl4-(ClC6H4N3C 6H4Cl)2] (1) is formed by the reaction of silver bis(p-chlorinephenyl)triazenide with [PPh4]Cl in THF. It crystallizes in the monoclinic space group C2/c with a = 2816.9(3), b = 946.67(7), c = 2552.4(3) pm, β = 90.22(1)° and Z = 4. In the centrosymmetric anion of 1 the four Ag atoms together with two Cl atoms form a distorted octahedron. The Ag atoms are in equatorial positions. They are bridged by two Cl atoms and two triazenido ligands. The reaction of [Et4N]Br with silver bis(p-tolyl)pentaazadienid in THF yields [Et4N][Ag 2(tolyl-N5-tolyl)3] (2a). An analogous compound, [(n-Bu)4N][Ag2(tolyl-N5-tolyl) 3] (2b) is obtained by the reaction of [(n-Bu)4N]I with silver bis(p-tolyl)pentaazadienid in THF, when a threefold excess of the pentaazadienid is used. If both educts are used in equal amounts then [(n-Bu)4N]3[Ag3I6] (3) is formed. 2a crystallizes as 2a×2THF in the triclinic space group P1 and a = 1303.6(3), b = 1471.3(4), c = 1811.6(2) pm, α = 98.51(2)°, β = 93.33(2)°, γ = 112.50(2)° and Z = 2. The two Ag atoms in the anions of 2a and 2b are bridged by three pentaazadienido ligands with their atoms N1 and N3. One of the Ag atoms is in addition coordinated by the atoms N5 of two of the ligands, resulting in different coordinations for the two Ag atoms in form of a trigonal planar for one and a distorted square pyramidal arrangement for the other. 3 forms orthorhombic crystals with the space group Pca21 and a = 1675.0(6), b = 1698.8(2), c = 2612.8(5) pm and Z = 4. The anion [Ag3I6]3- is built up by three AgI4 tetrahedra sharing common faces. The silver triazenido and pentaazadienido complexes, [Ag(ClC6H4N3C6H 4Cl]2 and [Ag(tolyl-N5-tolyl)]2 are oxidized by I2 to form the azo compounds [ClC6H 4N=NC6H4Cl] (4) and [tolyl-N=N-tolyl] (5) as well as N2.
Surfactant directed Ag1?xNix alloy nanoparticle catalysed synthesis of aromatic azo derivatives from aromatic amines
Kumar, Mukesh,Soni, Kiran,Yadav, Geeta Devi,Singh, Surendra,Deka, Sasanka
, p. 50 - 58 (2016)
A bimetallic and multiply twinned Ag1?xNix (x?=?0.2, 0.4, 0.6, 0.8) alloy nanoparticle (MTANP), for the first time has been explored as an efficient heterogeneous catalyst in the industrially important reaction conversion of aromatic amines to the symmetric or asymmetric azobenzenes by the activation of aerobic molecular oxygen. Here, we demonstrated that the as-synthesized and optimized Ag0.6Ni0.4 alloy NPs showed breakthrough in catalytic performance, enabling quantitative aromatic amine conversion and absolute selectivity in azobenzenes (100%) under aerobic green reaction conditions without using the environmentally unfriendly nitrites and any other hazardous materials. A high stability and recyclability of the catalyst are observed and investigated by several instrumental techniques. The key to the effective process is found to be size effect, electronic effect and structural defect, and the presence of surfactant at the surfaces of the AgNi MTANP catalyst.
Mechanistic insight into the Z-E isomerization catalysis of azobenzenes mediated by bare and core-shell gold nanoparticles
Simoncelli, Sabrina,Aramendía, Pedro F.
, p. 2110 - 2116 (2015)
We explored the catalytic effect of 15 nm diameter gold nanoparticles (AuNPs) upon the thermal Z-E isomerization reaction of azobenzene and nine 4 and 4-4′ substituted azobenzenes (ABs). The kinetics follows a first order rate in ranges of [ABs] = 5 to 50
Correlation studies in the oxidation of Vanillin Schiff bases by acid bromate - A kinetic and semi-empirical approach
Sathish,Teja, P. Ravi,Ramudu, M. Parusha,Manjari, P. Sunitha,Rao, R. Koteshwar
, (2021/12/13)
Kinetics and mechanistic aspects of oxidation of Vanillin Schiff bases (obtained from Vanillin and p-substituted anilines) by bromate in acid medium has been studied at 313 ?K. The reaction exhibited first order in [bromate] and less than unity order each in [Vanillin Schiff base] and [acid]. The increase in the rate of reaction with decrease in dielectric constant of the medium is observed with all the studied substrates. The reaction failed to induce the polymerization of acrylonitrile. Electron withdrawing substituents in the aniline ring moiety of Vanillin Schiff base accelerate the rate of oxidation to a large extent and electron releasing substituents retard the rate. The order of reactivity is found to be p-nitro ?> ?p-bromo ?> ?p-chloro ?> ?–H ?> ?p-fluoro ?> ?p-methyl ?> ?p-methoxy ?> ?p-ethoxy and the sensitivity of the substrates towards the reaction rate is further supported by the semi-empirical calculation of electronic properties and global descriptors of the substrates (Vanillin Schiff bases) with different substituents in the aniline ring moiety. The observed trend in the reactivity of the substrates was correlated with the calculated descriptors like electronegativity, chemical potential, electrophilicity index, chemical hardness and frontier molecular orbitals. The linear free-energy relationship is characterized by a straight line in the Hammett's plot of log k versus σ. The ρ values are positive and increase with increase in temperature. From the Exner and Arrhenius plots, the isokinetic relationship is discussed. Oxidation products identified are p-substituted azobenzene and vanillic acid. Based on the experimental observations, a plausible mechanism is proposed and rate law is derived.
