- Formation and photophysics of a stable concave-convex supramolecular complex of C60 and a substituted s-triazine derivative
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Spectroscopic, electrochemical and computational data (show that C60 and a highly phenylated s-triazine derivative form a stable supramolecular complex at micromolar concentrations in solution at ambient temperatures, due to strong van der Waals attraction between their complementary surfaces.
- Schuster, David I.,Rosenthal, Joel,MacMahon, Shaun,Jarowski, Peter D.,Alabi, Christopher A.,Guldi, Dirk M.
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Read Online
- Effect of Propanol-1 on the Reaction between Thiophenol and N,N'-Diphenyl-1,4-Benzoquinone Diimine in Chlorobenzene
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Abstract: It is found that the interaction between thiophenol and N,N '-diphenyl-1,4-benzoquinone diimine proceeds by two routes, one of which is a radical chain reaction and the other is a nonchain reaction between the reagents. The kinetic patterns of the reaction depend substantially on the concentration of propanol-1 in mixtures of it and chlorobenzene. It is shown that at 343 K, replacing chlorobenzene with propanol-1 results in an almost twentyfold increase in the total rate of the reaction. Increasing the concentration of propanol-1 raises the rate of both routes of the reaction, but that of the nonchain route grows more than that of the chain route. It is concluded that increasing the concentration of propanol-1 results in a simultaneous 20–30 times rise in the rate constants of both the stage of radical generation by the reaction between the reagents as well as the rate constant of the nonchain bimolecular reaction, and the chain length of the chain reaction is shortened. When chlorobenzene is replaced with propanol-1, the rate constant of the limiting stage of chain propagation (the reaction of quinone diimine with a phenylthiyl radical) is halved, due to the formation of H complexes between the π system of quinone diimine and the proton of propanol-1.
- Varlamov
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Read Online
- Continuous Synthesis of Aryl Amines from Phenols Utilizing Integrated Packed-Bed Flow Systems
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Aryl amines are important pharmaceutical intermediates among other numerous applications. Herein, an environmentally benign route and novel approach to aryl amine synthesis using dehydrative amination of phenols with amines and styrene under continuous-flow conditions was developed. Inexpensive and readily available phenols were efficiently converted into the corresponding aryl amines, with small amounts of easily removable co-products (i.e., H2O and alkanes), in multistep continuous-flow reactors in the presence of heterogeneous Pd catalysts. The high product selectivity and functional-group tolerance of this method allowed aryl amines with diverse functional groups to be selectively obtained in high yields over a continuous operation time of one week.
- Ichitsuka, Tomohiro,Kobayashi, Shū,Koumura, Nagatoshi,Sato, Kazuhiko,Takahashi, Ikko
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p. 15891 - 15896
(2020/07/13)
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- Preparation method of diaryl p-phenylenediamine anti-aging agent
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The invention provides a preparation method of a diaryl p-phenylenediamine anti-aging agent represented by a formula I, wherein the method comprises: carrying out a condensation dehydrogenation reaction on p-nitroaniline and a raw material B represented by a formula II in the presence of a solvent, a water-carrying agent and a catalyst, wherein R1 and R2 are respectively and independently H or C1-C6 alkyl, and R is H or C1-C6 alkyl.
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Paragraph 0069-0076
(2020/02/10)
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- Design, preparation and characterization of aerogel NiO-CuO-CoO/SiO2 nanocomposite as a reusable catalyst for C-N cross-coupling reaction
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Aerogels are porous, non-crystalline solid materials with high specific surface space, plentiful three-dimensional (3D) porous construction, ultra-low density and significant porosity. The aerogel nanocomposite is produced using sol-gel and supercritical drying processes. CO2 supercritical drying (SCD) is the most powerful process, ensuring optimal product properties such as high porosity, low density, and high thermal conductivity. On this account, we used the CO2 supercritical drying method to produce NiO-CuO-CoO/SiO2 nanocomposite aerogels and applied it as a reusable catalyst for the C-N cross-coupling reaction (Buchwald-Hartwig amination). Powerful catalytic activity for the C-N cross-coupling reaction was obtained for the new nanocomposite aerogel, that is, NiO-CuO-CoO/SiO2. The catalyst was characterized by X-ray Powder Diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), elemental mapping and Brunauer-Emmett-Teller (BET). Also, organic compounds were identified by melting point, Fourier-transform infrared spectroscopy (FT-IR) and hydrogen-1 nuclear magnetic resonance (1H NMR) analyses.
- Ghasemi, Amir Hossein,Naeimi, Hossein
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supporting information
p. 5056 - 5063
(2020/04/09)
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- Preparation method for aryl substituted p-phenylenediamine substance
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The invention provides a preparation method for an aryl substituted p-phenylenediamine substance. The aryl substituted p-phenylenediamine substance has the following structural formula defined in the specification, wherein R'' is phenyl or o-methyl phenyl, and R' and R'' are the same or different. The preparation method comprises the steps of carrying out a reaction of a raw material A and a raw materials B under the action of a hydrogen acceptor and a catalyst, to form the aryl substituted p-phenylenediamine substance, wherein the raw material A has the structural formula defined in the specification, the raw material B is cyclohexanone and/or o-methylcyclohexanone, and the hydrogen acceptor is a hydrogen acceptor which can accept hydrogen to be converted into the raw material B. The preparation method provided by invention has the advantages that the raw materials are cheap and easy to obtain, and reaction post-processing has no need of use of a lot of water. At the same time, the reaction conditions are mild, and equipment cannot be corroded. Therefore, the preparation method has the advantages of environmental protection and less pollution and can obtain better economic benefits.
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Paragraph 0042; 0043; 0044; 0045; 0046
(2017/06/02)
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- Electrochemical synthesis of N1,N4-diphenyl-2-(phenylsulfonyl)benzene-1,4-diamine derivatives: Introducing an example of ECDispCMich mechanism
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The electrochemical oxidation of N,N'-diphenyl-l,4-phenylenediamine (DPD) has been studied using cyclic voltammetry and controlled potential coulometry methods. The results revealed that DPD shows two one-electron oxidation-reduction peaks. In the first step DPD via a single-electron process is converted to the related radical cation (DPD.+) and second step is conversion of DPD.+ to N-(4-(phenylimino) cyclohexa-2,5-dienylidene) benzenamine (CHD) via a one-electron/two-protons process. Our results also show that DPD.+ participates in disproportionation reaction and is converted to DPD and CHD. The rate of this reaction is pH dependent and increases with increasing pH. Furthermore, the electrochemical oxidation of DPD has been studied in the presence of arylsulfinic acids as nucleophiles. The results showed that electrochemically generated CHD participates in Michael addition reaction with arylsulfinic acids via a novel ECDispCMich mechanism and is converted to the N1,N4-diphenyl-2-(phenylsulfonyl)benzene-1,4-diamine derivatives. In this work, a facile and green electrochemical method for the synthesis of some new N1,N4-diphenyl-2-(phenylsulfonyl)benzene-1,4-diamine derivatives in good yields using controlled-potential electrolysis at a carbon electrode is also reported.
- Kaihani, Sajad,Salehzadeh, Hamid,Nematollah, Davood
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p. 166 - 174
(2015/02/05)
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- Modular Synthesis of Biaryl-Substituted Phosphine Ligands: Application in Microwave-Assisted Palladium-Catalyzed C-N Cross-Coupling Reactions
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Biaryl-substituted monophosphine-based ligands have been synthesized by transition-metal-free "ARYNE" cross-coupling reaction of aryllithiums with 1,2-dibromobenzene and subsequent regioselective functionalization through bromine-lithium interconversion. These ligands were employed in palladium-catalyzed C-N bond-forming reactions. The reaction was found to be general with wide substrate applicability. A wide variety of both primary and secondary amines were successfully coupled with an array of differently substituted halobenzenes under microwave irradiation to give the expected products in good to excellent yields. A number of biaryl-substituted phosphine ligands screened for the coupling reaction showed that steric bulk and the electronic properties of substituents on phosphorus play a crucial role in governing the catalytic activity of C-N cross-coupling reactions. Biaryl-substituted monophosphines have been synthesized by transition metal free ARYNE cross-coupling reactions and subsequent regioselective functionalization through bromine-lithium interconversion. These ligands were employed in palladium-catalyzed C-N bond-forming reactions.
- Singh, Chandani,Rathod, Jayant,Jha, Vishwajeet,Panossian, Armen,Kumar, Pradeep,Leroux, Frédéric R.
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p. 6515 - 6525
(2015/10/19)
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- Addressing challenges in palladium-catalyzed cross-couplings of aryl mesylates: Monoarylation of ketones and primary alkyl amines
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Mor(DalPhos) for Me(sylates): Described are the first examples of ketone mono-α-arylation and primary aliphatic amine monoarylation employing aryl methanesulfonate coupling partners. A range of functionalized aryl mesylates were employed with dialkyl ketones, and also with primary and secondary amines as well as the otherwise challenging coupling partners acetone and methylamine. Ad=adamantyl. Copyright
- Alsabeh, Pamela G.,Stradiotto, Mark
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supporting information
p. 7242 - 7246
(2013/07/26)
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- BippyPhos: A single ligand with unprecedented scope in the Buchwald-Hartwig amination of (hetero)aryl chlorides
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Over the past two decades, considerable attention has been given to the development of new ligands for the palladium-catalyzed arylation of amines and related NH-containing substrates (i.e., Buchwald-Hartwig amination). The generation of structurally diverse ligands, by research groups in both academia and industry, has facilitated the accommodation of sterically and electronically divergent substrates including ammonia, hydrazine, amines, amides, and NH heterocycles. Despite these achievements, problems with catalyst generality persist and access to multiple ligands is necessary to accommodate all of these NH-containing substrates. In our quest to address this significant limitation we identified the BippyPhos/[Pd(cinnamyl)Cl]2 catalyst system as being capable of catalyzing the amination of a variety of functionalized (hetero)aryl chlorides, as well as bromides and tosylates, at moderate to low catalyst loadings. The successful transformations described herein include primary and secondary amines, NH heterocycles, amides, ammonia and hydrazine, thus demonstrating the largest scope in the NH-containing coupling partner reported for a single Pd/ligand catalyst system. We also established BippyPhos/ [Pd(cinnamyl)Cl]2 as exhibiting the broadest demonstrated substrate scope for metal-catalyzed cross-coupling of (hetero)aryl chlorides with NH indoles. Furthermore, the remarkable ability of BippyPhos/[Pd(cinnamyl)Cl] 2 to catalyze both the selective monoarylation of ammonia and the N-arylation of indoles was exploited in the development of a new one-pot, two-step synthesis of N-aryl heterocycles from ammonia, ortho- alkynylhalo(hetero)arenes and (hetero) aryl halides through tandem N-arylation/hydroamination reactions. Although the scope in the NH-containing coupling partner is broad, BippyPhos/[Pd(cinnamyl)Cl]2 also displays a marked selectivity profile that was exploited in the chemoselective monoarylation of substrates featuring two chemically distinct NH-containing moieties.
- Crawford, Sarah M.,Lavery, Christopher B.,Stradiotto, Mark
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supporting information
p. 16760 - 16771
(2014/01/06)
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- Intervalence charge transfer in mixed valence compound modified by the formation of a supramolecular complex.
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The electrochemical and spectroelectrochemical properties of N,N-diphenyl-1,4-phenylenediamine (PDA) were investigated in the absence and in the presence of 18-crown-6-ether (18C6) or dibenzo 24-crown-8-ether (DB24C8), in a solution of tetrabutylammonium hexafluorophosphate (TBAPF6) in acetonitrile and in the presence of trifluoroacetic acid (TFA) only for 18C6. In neutral acetonitrile, PDA undergoes two reversible oxidation processes, which lead first to the formation of the cation-radical considered as mixed valence (MV) compound, and then to the dicationic species. When 18C6 is added in the medium and depending on 18C6 concentration, cyclic voltammetry shows a marked shift to more cathodic potentials of the current waves of the second redox process only. This is attributed to a strong interaction between the PDA+2 dication and two 18C6 molecules, leading to the formation of a supramolecular complex with an association constant value Ka = 7.0 × 107 M-2. The interaction of 18C6 with PDA+2 dication has a direct effect on the PDA+. cation-radical corresponding to a decrease in the lifetime of the MV compound and of the intramolecular electron transfer rate when 18C6 is present. Indeed, it results in a large decrease in the intervalence charge transfer (IV-CT) between the two amine centers in the MV compound (kth = 1.35 × 1010 s-1 in 18C6-free neutral solution containing 5.0 × 10-4 M PDA, and kth = 3.6 × 109 s-1 in the same medium at [18C6]/[PDA] = 20/1). And the comproportionation constant Kco falls from 6.0 × 106 in 18C6-free solution to 1.6 × 10 3 at [18C6]/[PDA] = 20/1. In acidified acetonitrile and when TFA concentration is increased, PDA still shows the two successive and reversible oxidation processes, but both are shifted to more anodic potentials. However, when 18C6 is added, the two oxidation waves shift to more cathodic potentials, indicating an interaction of all protonated PDA redox states with 18C6, resulting in the formation of supramolecular complexes. In the presence of TFA, the value of Kco is decreased to 4.3 × 104, but it remains unchanged when 18C6 is added, indicating no change in the lifetime of the MV compound. In this medium, IV-CT in the MV compound is greater with 18C6 (kth = 2.3 × 1010 s-1 for [18C6]/[PDA] = 20/1) than without (kth = 1.4 × 109 s-1), which indicates a more important IV-CT rate when 18C6 is present. The results show for the first time that is it possible to control the IV-CT rate, through the lifetime and the potential range where the MV compound is the most important. This control is not obtained as usual by chemical modification of the structure of the starting molecule, but by varying either the acidity or the 18C6 concentration as external stimuli, which lead to reversible formation/dissociation of a supramolecular complex species. Moreover, we also studied the electrochemical properties of PDA in the presence of wider crown ether such as DB24C8. We showed that PDA undergoes the same electrochemical behavior with DB24C8 than with 18C6 in neutral organic medium (Ka = 2.9 × 103 M-1). This result suggests that the complexation between the electrogenerated PDA+2 dication and the crown ethers may occur through face-to-face mode rather than rotaxane mode even with DB24C8 which is supposed to form inclusion complexes.
- Mechouet, Mourad,Perruchot, Christian,Maurel, Francois,Aeiyach, Salah,Bucher, Christophe,Chardon, Sylvie,Jouini, Mohamed
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scheme or table
p. 970 - 978
(2012/03/13)
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- Estimation of kinetic parameters of reversible chain reactions of quinoneimines with hydroquinones having self-acceleration periods
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A new approach is suggested for determining the kinetic parameters and rate constants of the elementary steps of reversible chain reactions having self-acceleration periods due to the long time required for the concentrations of the chain-carrier radicals to reach their steady-state values. This approach is illustrated by the example of the reversible chain reaction between N,N′-diphenyl-1,4-benzoquinonediimine and 2,5-dichlorohydroquinone in chlorobenzene. The disappearance rate of one of the initial reactants, N,N′-diphenyl-1,4-benzoquinonediimine, at the inflection point of its disappearance curve, is considered as the basic kinetic characteristic of the reaction. The empirical function y = aexp(bt c ) + d, where a, b, c, and d are the fitted parameters (b 1), is suggested for approximating the S-shaped kinetic curves and for calculating the reaction rate. The rate constants of the elementary steps are preferably derived from experimental data obtained at equal concentrations of the initial reactants, and also product additions when their effect on the reaction rate is studied. The effective rate constant of chain termination is derived from the time to reach the steady state. The results obtained in this way are compared with earlier data obtained using the "initial" reaction rates calculated by means of exponential approximation of portions of N,N′-diphenyl-1,4- benzoquinonediimine disappearance curves after the inflection point.
- Varlamov,Gadomsky
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experimental part
p. 657 - 665
(2011/02/16)
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- A serendipitous C-C bond formation reaction between michael donors and diiminoquinoid ring assisted by quaternary ammonium fluoride
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An efficient C-C bond formation reaction assisted by a fluoride ion has been Identified for N,N'-diphenyl-1,4-phenylenediimine with the compounds having an active methylene group. The reaction follows the typical Michael addition fashion and proceeds to c
- Paike, Vijaykumar V.,Balakumar,Chen, Hsin-Yu,Shih, Hong-Pin,Han, Chien-Chung
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supporting information; experimental part
p. 5586 - 5589
(2010/04/03)
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- LIGANDS FOR TRANSITION-METAL-CATALYZED CROSS-COUPLINGS, AND METHODS OF USE THEREOF
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Ligands for transition metals are disclosed herein, which may be used in various transition-metal-catalyzed carbon-heteroatom and carbon-carbon bond-forming reactions. The disclosed methods provide improvements in many features of the transition-metal-catalyzed reactions, including the range of suitable substrates, number of catalyst turnovers, reaction conditions, and efficiency. For example, improvements have been realized in transition-metal-catalyzed cross-coupling reactions.
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Page/Page column 135; 137
(2009/07/17)
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- A highly active catalyst for Pd-catalyzed amination reactions: Cross-coupling reactions using aryl mesylates and the highly selective monoarylation of primary amines using aryl chlorides
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A catalyst system based on a new biarylmonophosphine ligand (BrettPhos) that shows excellent reactivity for C-N cross-coupling reactions is reported. This catalyst system enables the use of aryl mesylates as a coupling partner in C-N bond-forming reactions. Additionally, the use of BrettPhos permits the highly selective monoarylation of an array of primary aliphatic amines and anilines at low catalyst loadings and with fast reaction times, including the first monoarylation of methylamine. Lastly, oxidative addition complexes of BrettPhos are included, which provide insight into the origin of reactivity for this system. Copyright
- Fors, Brett P.,Watson, Donald A.,Biscoe, Mark R.,Buchwald, Stephen L.
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supporting information; scheme or table
p. 13552 - 13554
(2009/02/06)
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- Stabilization of polymers with styrenated-p-cresols
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Disclosed herein is a process for the preparation of a mixture of styrenated p-cresol species that is liquid at room temperature and has a viscosity of less than 40,000 cps at 25° C., wherein said process affords 2,6-distyrenated p-cresol assaying at 70% minimum by GC area percent, comprising reacting styrene with p-cresol at a molar ratio of 1.85 to 2.1:1, respectively, in the presence of an acid catalyst at elevated temperature, wherein said mixture comprises monostyrenated-p-cresol, distyrenated-p-cresol, and tristyrenated-p-cresol and exhibits an acid number of less than 0.1 mg KOH/gram.
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- Solvent effect on the equilibrium constant of the chain reversible reaction of N,N'-diphenyl-1,4-benzoquinonediimine with 2,5-dichlorohydroquinone
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The temperature dependences of the equilibrium constant K of the reversible chain reaction of N,N'-diphenyl-1,4-benzoquinonediimine with 2,5-dichlorohydroquinone in benzene, chlorobenzene, anisole, benzonitrile, and CCl4 were studied. The enthalpies and entropies of the reaction in these solvents were determined, and a linear dependence between them in aromatic solvents was found. The equilibrium constant depends on the solvent nature: the replacement of CCl4 by benzene at T = 298 K increases K from 13.6 to 140. The solvation effects are caused by several types of intermolecular interactions of participants of equilibrium with the medium. The decrease in K in the benzene-anisole-benzonitrile series is related, to a great extent, to complex formation with hydrogen bonding between 2,5-dichlorohydroquinone and the solvents. In anisole a charge-transfer complex is formed between the solvent and reaction product (2,5-dichloroquinone). The constant and enthalpy of the complexation were estimated.
- Gadomsky,Varlamov
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body text
p. 2376 - 2383
(2009/02/05)
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- Determination of dissociation energies of N-H bond in the 4-anilinodiphenylaminyl radical and O-H bond in the 2,5-dichloro-4- hydroxyphenoxyl radical from the equilibrium constants of chain reactions in quinoneimine-hydroquinone systems
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The temperature dependences of the equilibrium constants of two chain reversible reactions in quinonediimine (quinonemonoimine)-2,5- dichlorohydroquinone systems in chlorobenzene were studied. The enthalpy of equilibrium of the reversible reaction of quinonediimine with 4-hydroxydiphenylamine was estimated from these data (ΔH = - 14.4±1.6 kJ mol-1) and a more accurate value of the N-H bond dissociation energy in the 4-anilinodiphenylaminyl radical was determined (DNH = 278.6±3.0 kJ mol-1). A chain mechanism was proposed for the reaction between quinonediimine and 2,5-dichlorohydroquinone, and the chain length was estimated (ν = 300 units) at room temperature. Processing of published data on the rate constant of the reaction of styrylperoxy radicals with 2,5-dichlorohydroquinone in the framework of the intersecting parabolas method gave the O-H bond dissociation energy in 2,5-dichlorohydroquinone: DOH = 362.4±0.9 kJ mol-1. Taking into account these data, the O-H bond dissociation energy in the 2,5-dichlorosemiquinone radical was found: DOH = 253.6±1.9 kJ mol-1.
- Antonov,Gadomsky,Varlamov
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p. 1723 - 1728
(2008/02/09)
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- The different electronic natures displayed by the alkylthio groups in simple and higher conjugated aniline systems
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Systematic studies based on 1H NMR and 13C NMR indicated that the alkylthio group behaves as a weak electron-withdrawing group in a simple aniline system like 2-butylthioaniline, while the same alkylthio group clearly acted as a resonance electron-donating group in higher conjugated aniline trimer systems, like butylthio-substituted PDA (mono-PDA) and dibutylthio-substituted PDA (2,6-diPDA). The formation of 2,6-diPDA as the major byproduct during the preparation of mono-PDA from PDI and butane-1-thiol provided additional support for the resonance electron donating nature of the butylthio group in these aniline trimer systems. Furthermore, CV studies also clearly indicated that the redox potential E° (vs. SCE) of the aniline trimer systems decreased with the increase in the number of butylthio groups, further confirming the electron-donating nature of the butylthio group in these higher conjugated trimer systems. The Royal Society of Chemistry 2006.
- Han, Chien-Chung,Balakumar,Thirumalai,Chung, Ming-Tsu
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p. 3511 - 3516
(2008/09/17)
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- Nickel(0)/N-heterocyclic carbene complexes catalysed arylation of aromatic diamines
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Nickel complexes of N-heterocyclic carbenes were examined for effecting C-N coupling reactions between aromatic diamines and aryl chlorides of varying electron density. The Ni(0) ? 2IPr (IPr = N,N′-bis(2,6- diisopropylphenyl)imidazol-2-ylidene) complex associated to t-BuONa allowed N,N′-diarylation at 100 °C in 1,4-dioxane with excellent yields. Selective monoarylation of diamines could be performed in THF at 65 °C.
- Kuhl, Sébastien,Fort, Yves,Schneider, Rapha?l
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p. 6169 - 6177
(2007/10/03)
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- N-H bond dissociation energies in N,N′-diphenyl-1,4-phenylenediamine and its aminyl radical
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The N-H bond dissociation energy (DNH) in the 4-anilinodiphenylaminyl radical formed from N,N′-diphenyl-1,4- phenylenediamine was experimentally determined and calculated by the quantum-chemical method. The experimental DNH value was found from the enthalpy of the reaction of N,N′-diphenyl-1,4-benzoquinonediimine with 4-hydroxydiphenylamine taking into account the bond dissociation energies in 4-hydroxydiphenylamine and its aminyl and phenoxyl radicals, which were determined by the intersecting parabolas method from the kinetic data. The quantum-chemical calculations of DNH used several semiempirical methods by the MOPAC program and the ab initio and DFT methods by the GAUSSIAN 94/98 program. The DNH values, which were closest to the experimental values, were obtained by the B3LYP/6-31+G*method. The results of quantum-chemical calculations of the N-H and O-H bond dissociation energies in 4-hydroxydiphenylamine and its radicals are presented.
- Varlamov,Krisyuk
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p. 1609 - 1614
(2007/10/03)
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- Synthesis of thiol substituted oligoanilines for molecular device candidates
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The synthesis of thioacetate derivatized oligoanilines designed for molecular electronic device purposes is described. Reversible oxidation between the non-conductive leuco base and conductive emeraldine salt forms of these compounds may produce switching effects and device behavior. The targeted compounds contain a sulfur moiety as a means to connect the molecules to metallic electrodes.
- Flatt, Austen K.,Tour, James M.
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p. 6699 - 6702
(2007/10/03)
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- On attempted oxidative cyclisation of isomeric N,N'-diphenylphenylenediamines and their N,N'-dimethyl derivatives by palladium(II) acetate and UV light
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The cyclisation of N,N'-diphenyl-o-, m- and p-phenylenediamines and their N,N'-dimethyl derivatives by palladium(II) acetate and UV light separately led to both bis-cyclisation, furnishing indolocarbazoles, and mono-cyclisations with cleavage as well as retention of one substituent, producing substituted carbazoles.
- Chakrabarty,Batabyal,Khasnobis
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p. 3651 - 3668
(2007/10/03)
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- Easily transportable and meterable mixtures of aromatic oils and phenylenediamines having high stability in storage
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This invention relates to easily conveyable and easily meterable mixtures having high stability in storage, containing aromatic mineral oils and phenylenediamines, the content of phenylenediamines in the mixture being 1 to 99 wt. %. The mixtures of mineral oils and phenylenediamines according to the invention are used in the production of rubbers and rubber articles.
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- Compositions and methods for inhibiting vinyl aromatic monomer polymerization
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Methods and compositions are provided for inhibiting the polymerization of vinyl aromatic monomers under distillation conditions. The compositions comprise a combination of a phenylenediamine compound and a hydroxylamine compound.
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- REACTIONS OF N,N'-DIPHENYL-p-QUINONEDIIMINE WITH HYDROQUINONE, α-TOCOPHEROL, AND OTHER ANTIOXIDANTS
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Phenols (hydroquinone and α-tocopherol) and heterocyclic aminophenols (2,2,4-trimethyl-6-ethoxy-1,2-dihydroquinoline) reduce N,N'-diphenyl-p-quinonediimine (A) to the diamine.With difunctional hydrogen atom donors, the reaction rate is proportional to the concentrations of the reactants.The effective rate constants have been determined over a range of temperatures.In the reaction of A with α-tocopherol, plots of rate versus initial concentrations are nonlinear. 2,6-Di-tert-butyl-4-methylphenol and 2,2,4-trimethyl-6-ethoxy-1,2-dihydroquinoline do not react with A under the same conditions.Keywords: N,N'-diphenyl-p-quinonediimide, reduction kinetics, hydroquinone, 2,2,4-trimethyl-6-ethoxy-1,2-dihydroquinoline, 2,6-di-tert-butyl-4-methylphenol (ionol), α-tocopherol, oxidation potentials.
- Kasaikina, O. T.,Kartasheva, Z. S.,Mazaletskii, A. B.,Sakova, N. Yu.,Shmyreva, Zh. V.,Shikaliev, Kh. S.
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p. 329 - 332
(2007/10/02)
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- 2-Propanol derivatives as corrosion inhibitors
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New composition comprises a functional fluid in contact with ferrous metal and a corrosion inhibiting amount of at least one compound of formula (I) STR1 or a derivative thereof in which R1, R2 and R3 are, independently, hydrogen, a C1 -C15 straight or branched chain alkyl residue, a C5 -C12 cycloalkyl residue, a C6 -C15 aryl residue or C7 -C12 alkaryl residue, and R4 and R5 are, independently, hydrogen, 2-hydroxyethyl or 2-hydroxypropyl with the provisos that (a) R4 and R5 are not simultaneously hydrogen, (b) when R4 and R5 are each --CH2 --CH2 --OH, R1 and R2 are not simultaneously hydrogen and R3 is not a pentyl residue and (c) that polyalkylene and phenol or polycarboxylic ester co-additives are absent; as well as salts thereof. Some of the compounds of formula I are new.
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- Corrosion inhibiting composition
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A composition, in contact with a corrodable metal surface, which composition comprises: (a) an aqueous-based or oil-based system; and (b) as inhibitor for protecting the metal surface against corrosion, at least one compound having the formula I: STR1 as well as salts or partial esters thereof wherein: n is 0 or an integer ranging from 1 to 20, R is a straight or branched chain C4 -C30 alkyl group, optionally interrupted by one, two or three oxygen atoms or substituted by one, two or three hydroxy groups, a C5 -C12 cycloalkyl group, a C6 -C10 aryl group optionally substituted by one, two or three C1 -C12 alkyl groups, or a C7 -C13 aralkyl group which is optionally substituted by a hydroxyl group; R1 is H or a straight- or branched chain C1 -C4 alkyl group; R2 is H, a straight or branched chain C1 -C4 alkyl group or CO2 H; R3 is H, a straight or branched chain C1 -C4 alkyl group, --CH2 CO2 H or --CH2 CH2 CO2 H; R4 is H, a straight or branched chain C1 -C4 alkyl group or CO2 H; R5 is H, a straight or branched chain C1 -C4 alkyl group, CH2 CO2 H or CH2 CH2 CO2 H; provided that at least one group R4 must be CO2 H, with the provisio, that compositions comprising an oil-based system and a compound having the formula STR2 wherein R, R1 and R2 are hydrogen or alkyl radicals, having a total from 10 to 38 C-atoms, are excluded.
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- Triazole-organodithiophosphate reaction product additives for functional fluids
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New reaction products, useful as additives for functional fluids, are obtained by reacting, at elevated temperature, (A) a triazole having the formula IA or IB: STR1 wherein R7 is hydrogen or a C1 -C20 alkyl residue; R8 and R9 are the same or different and each is C1 -C20 alkyl, C3 -C20 alkenyl, C5 -C12 cycloalkyl, C7 -C13 aralkyl, C6 -C10 aryl or R8 and R9, together with the nitrogen atom to which they are attached, form a 5-, 6- or 7-membered heterocyclic residue or R8 and R9 is each a residue of formula: wherein X is O, S or N(R12), R12 is hydrogen or C1 -C20 alkyl, "alkylene" is a C1 -C12 alkylene residue and n is 0 or an integer from 1 to 6; R10 is hydrogen, C1 -C20 alkyl or C6 -C10 aryl or C7 -C18 alkyl phenyl; and R11 is hydrogen, C1 -C20 alkyl or a residue --CH2 NR8 R9 wherein R8 and R9 have their previous significance; with (B) an organodithiophosphate having the formula: STR2 in which R13 is a C1 -C20 alkyl or C7 -C18 alkyl phenyl or C7 -C13 aralkyl group, M is a metal ion of Group IA, IB, IIA, IIB, VB, VIB, VIIB or VIII of the Periodic System of Elements, and y is the valency of M.
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- Poly(p-phenyleneamineimine): Synthesis and Comparison to Polyaniline
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We present a complete account of results on the preparation of a polymer which could only be a poly(p-phenyleneamineimine) (PPAI) and which, by several criteria, has the same properties of polyaniline (PANI).We also present detailed results of comparative studies of not only PANI with PPAI but of PANI with phenyl-capped octaaniline (COA), a discrete length, fully characterized molecule.Finally, we present support for the hypothesis that acid doping of PANI involves the proton induced spin unpairing mechanism for protonated quinoneimine moieties.We conclude that magnetic and transport data are qualitatively consistent with that of a Fermi"glass" model and not with that of a metal.
- Wudl, F.,Angus, R. O.,Lu, F. L.,Allemand, P. M.,Vachon, D. J.,et al.
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p. 3677 - 3684
(2007/10/02)
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- Aromatic aryl amine polymers
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A polymer of the formula STR1 wherein Φ=phenyl or phenylene b=0, 1, 2 or 3 n=3 or greater.
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- Electron Spin Resonance Studies on the Reactive Character of Chlorine Dioxide (ClO2) Radical in Aqueous Solution
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The reactivities of the ClO2 radical towards some organic substrates were investigated in aqueous solution by use of a rapid-mixing flow technique coupled with electron spin resonance spectroscopy.The ClO2 radical could oxidize some aromatic amines to the corresponding cation radicals, whereas it could neither abstract hydrogen from saturated compounds such as methanol and ethanol nor add to unsaturated compounds having a double or triple bond.Keywords-chlorine dioxide; ClO2 radical; rapid-mixing flow technique; ESR; aromatic amine; cation radical; Wurster's salt
- Ozawa, Toshihiko,Kwan, Takao
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p. 1587 - 1589
(2007/10/02)
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- Process for making diarylamines
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An improved process for preparing diarylamines from alicyclic ketones, a primary aromatic amine, and a hydrogen acceptor, in the presence of a platinum metal catalyst and an acid promoter.
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- Para-aminophenol derivatives
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A process for the preparation of diaryl para-phenylenediamines from a crude para-aminophenol solution such as obtained by the catalytic hydrogenation of nitrobenzene in an aqueous acid reaction medium. The process comprises contacting the para-aminophenol containing acidic solution, after neutralization with ammonia, with an aromatic amine selected from the group consisting of aniline, mixed toluidines, ortho-toluidine, mixed xylidines, and mixtures thereof under conditions whereby the aromatic amine extracts the para-aminophenol from the crude feed solution and is separated therefrom. The separated solution comprised essentially of the aromatic amine extractant, para-aminophenol, and minor amounts of impurities is then contacted with an alkylation catalyst to produce the diaryl para-phenylenediamines.
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- REACTION OF SODIUM SALTS OF AROMATIC SULFONIC ACIDS WITH ALKALI-METAL ARYLIDES
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In the reaction of the sodium salts of benzenesulfonic acid, 1-naphthalenesulfonic acid, and 2-methyl-6-naphthalenesulfonic acid with alkali-metal arylides the sulfo groups are substituted by arylamino groups, and diphenylamine, N-phenyl-1-naphthylamine, N-(p-tolyl)-2-naphthylamine, 2-methyl-N-phenyl-6-naphthylamine, and dinaphthylamine are formed.In the reaction of disodium salts of aromatic disulfonic acids with sodium anilide substitution of the sulfo groups by arylamino groups gave N,N'-diphenyl-m-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, and N,N'-diphenyl-2,6-naphthylenediamine.
- Shein, S. M.,Rusov, V. P.,Sokolenko, V. I.
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p. 2014 - 2016
(2007/10/02)
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- Recovery of para-aminophenol
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An improved method for the recovery of para-aminophenol from crude solutions thereof such as obtained by the catalytic hydrogenation of nitrobenzene in an aqueous acid reaction medium. The method comprises neutralizing the cold, acidic solution containing the crude para-aminophenol whereby a very fine fluffy para-aminophenol precipitates. When an aromatic amine selected from the group consisting of aniline, mixed toluidines, ortho-toluidine, mixed xylidines, and mixtures thereof is admixed therewith an upper layer containing the para-aminophenol suspended in the aromatic amine forms when allowed to settle. A clear lower layer containing about 70 to 90% of the ammonium sulfate solution is separated and discarded. The upper layer which contains the aromatic amine and the para-aminophenol can be used as a source of para-aminophenol for producing para-aminophenol derivatives such as diaryl para-phenylenediamines.
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- Method for the production of vinyl norbornene
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A method for producing vinyl norbornene at a high yield preventing the formation of Diels-Alder reaction by-products which is characterized in that cyclopentadiene and butadiene are reacted in the presence of p-phenylenediamine compounds such as N-isopropyl-N'-phenyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine and the like.
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- Nickel stabilizers for synthetic polymers
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New complexes of nickel salts of hydroxybenzoic acids are stabilizers for polymers. The complexes are prepared by reacting a nickel benzoate with a corresponding alcohol.
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- Piperidine derivatives
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A composition comprising an organic material and, as stabiliser, a compound having the formula SPC1 And salts thereof, wherein R1 and R2 are the same or different and each is an alkyl residue having from 1 to 12 carbon atoms or R1 and R2, together with the carbon atom to which they are bound, form a cycloalkyl residue having from 5 to 12 carbon atoms in the ring, Y is O, hydrogen, a straight or branched alkyl residue having from 1 to 20 carbon atoms, an alkenyl or alkynyl residue having from 3 to 12 carbon atoms, an aralkyl residue having from 7 to 12 carbon atoms or a group having the formula EQU1 wherein R is hydrogen, or a methyl or phenyl residue and R3 is hydrogen or a straight- or branched chain alkyl residue having from 1 to 12 carbon atoms.
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