- Synthesis and properties of 4-[(E)-(4'-R-phenyl)diazenyl]phthalonitriles and cobalt phthalocyanines obtained therefrom
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The diazotization-azocoupling method has been utilized to prepare a series of previously unknown 4-[(E)-(4'-R-phenyl)diazenyl]phthalonitriles, which were further transformed into the corresponding cobalt phthalocyanines. The effect of the peripheral substitution of the phthalocyanine ligand on the spectral properties of the prepared compounds has been demonstrated.
- Tikhomirova,Gruzdeva,Shaposhnikov
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- Industrial-scale palladium-catalyzed coupling of aryl halides and amines - A personal account
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The palladium-catalyzed coupling of amines and aryl halides or aryl alcohol derivatives has matured from an exotic small-scale transformation into a very general, efficient and robust reaction during the last ten years. This article reports several applications of this method from an industrial vantage point, including ligand synthesis, synthesis of arylpiperazines, arylhydrazines and diarylamines. Much emphasis in placed on issues of scale-up and safety to underline the potential of C-N couplings as solutions for industrial-scale synthetic problems.
- Buchwald, Stephen L.,Mauger, Christelle,Mignani, Gerard,Scholz, Ulrich
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- Preparation of N-phenyl-p-phenylenediamine by coupling of aniline and nitrobenzene in KOH–poly(ethylene glycol) medium
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A novel protocol for efficient coupling of nitrobenzene and aniline in poly(ethylene glycol) medium in the presence of KOH giving diphenylamine derivatives has been developed, to enable the exclusion of the toxic tetramethylammonium hydroxide catalyst commonly used in the rubber antidegradant industry.
- Babkin, Alexander V.,Asachenko, Andrey F.,Uborsky, Dmitry V.,Kononovich, Dmitry S.,Izmer, Vyatcheslav V.,Kudakina, Vera A.,Shnaider, Viktoriya A.,Shevchenko, Nikolay E.,Voskoboynikov, Alexander Z.
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- Surface-Enhanced Raman Spectroscopy as a Probe of Electroorganic Reaction Pathways. 2. Ring-Coupling Mechanisms during Aniline Oxidation
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The adsorbed ring-coupling products formed during aniline electrooxidation at gold-aqueous interfaces have been identified by means of real-time surface-enhanced Raman-spectroscopy (SERS) in conjunction with linear sweep voltammetry.In the absence of solution species, the electrooxidation of irreversibly adsorbed aniline yields predominantly adsorbed benzidine.In the presence of solution aniline, however, the "head-to-tail" dimer N-phenyl-1,4-phenylenediamine (PPDA) as well as benzidine is formed at the interface, the proportion of the former adsorbate increasing toward higher pH and larger aniline concentrations.A distinction between these interfacial reaction products can readily be made from the characteristic and intense SER spectra of the two-electron oxidation products formed from PPDA and benzidine.Markedly different ring-coupling product distributions were formed in solution (i.e., within the diffusion layer) as deduced voltammetrically, PPDA predominating except in strong acidic media.Possible reasons for these observed differences are discussed.In alkaline media, azobenzene is observed to be the major ring-coupling product in both adsorbed and solution-phase environments.
- Gao, Ping,Gosztola, David,Weaver, Michael J.
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- 2,6-Bis(diphenylphosphino)pyridine: A simple ligand showing high performance in palladium-catalyzed CN coupling reactions
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The use of commercially available 2,6-bis(diphenylphosphino)pyridine as a ligand in conjunction with K2CO3, DMAc and TBAB is an effective method for the palladium-catalyzed CN coupling of a variety of aryl halides with anilines, N-heterocyclic aromatic amines, and a cyclic secondary amine. The reactions proceed in good to excellent yield (up to 98%) while the loading of Pd(OAc)2 was as low as 0.025 mol %.
- Nadri, Shirin,Rafiee, Ezzat,Jamali, Sirous,Joshaghani, Mohammad
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- A New Route to 4-Aminodiphenylamine via Nucleophilic Aromatic Substitution for Hydrogen: Reaction of Aniline and Azobenzene
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A new example of nucleophilic aromatic substitution for hydrogen is described which encompasses reacting aniline and azobenzene (1) in the presence of base under aerobic conditions to generate 4-(phenylazo)diphenylamine (2) in high yield.Monitoring the time course of the reaction under anaerobic conditions revealed that hydrazobenzene (9) was formed as an intermediate in the reaction in equal molar amounts as 2.However, under aerobic conditions 9 was shown not to persist in the reaction mixture.The kinetic effect of isotopic substitution on this reaction was probed by competition experiments utilizing equal molar mixtures azobenzene-d10 and undeuterated material which gave a kH/kD of 4.6 +/- 0.1.It was concluded from these studies that azobenzene was functioning as both the electrophile and oxidant in this reaction.Catalytic hydrogenation of 2 generates 4-aminodiphenylamine (4-ADPA) (10) and aniline.These reactions form the basis of a novel synthetic route to 4-ADPA which does not utilize halogenated intermediates or reagents and ultimately relies on O2 as the terminal oxidant in the system.
- Stern, Michael K.,Cheng, Brian K.,Hileman, Frederick D.,Allman, James M.
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- Gold(I)-mediated rearrangement of 1,2-diphenylhydrazine to semidines
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Reaction of 1,2-diphenylhydrazine with the gold oxo complex [(PPh3Au)3(μ-O)]BF4 gives a mixture of [(Ph3PAu)3(μ-N-1,4-C6H 4-NHPh)]BF4 (1; 82%) and [(Ph3PAu)3(μ-N-1,2-C6H 4-NHPh)]BF4 (2; 18%) in CH2-Cl2 at ambient temperature, A crossover experiment using a 1:1 mixture of 1,2-diphenylhydrazine and 1,2-diphenylhydrazine-d10 indicates that the rearrangement process is intramolecular.
- Xia, Aibing,James, Alan J.,Sharp, Paul R.
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- Reduction of 4-nitrosodiphenylamine with sodium hydroxy- and aminoalkanesulfinates
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The kinetics of reduction of 4-nitrosodiphenylamine with sodium alkanesulfinates were studied, and the reaction mechanism was suggested.
- Polenov,Egorova,Ryazantseva
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- Heterogeneous Catalytic Transfer Hydrogenation of 4-Nitrodiphenylamine to p-Phenylenediamines
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p-Phenylenediamine analogues have been prepared from 4-nitrodophenylamine (1) by catalytic transfer hydrogenation in one stage; the process can be extended to the general condensation of a nitro compound with an alcohol (with Raney nickel as catalyst) or a ketone (with palladium as catalyst).
- Banerjee, Ankur A.,Mukesh, Doble
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- Superoxide-Promoted Oxidation Reactions of Aniline and N-Methylaniline in Dimethyl Sulfoxide
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The chemistry of superoxide was investigated in reference to its reactions with primary and secondary aromatic amines.Two aromatic amines (aniline and N-methylaniline) reacted extensively in aprotic solutions containing potassium superoxide.In the case of aniline, trans-azobenzene and 4-nitrodiphenylamine were the major products, with smaller amounts of 4-aminodiphenylamine, 4-nitrosodiphenylamine, and p-(phenylazo)diphenylamine also being produced.With N-methylaniline, both oxidation and demethylation occurred, leading to the isolation of N-phenylformamide, aniline,and smaller amounts of azobenzene and 4-nitrodiphenylamine.Both superoxide and hydrogen peroxide alone were unable to convert either 4-aminodiphenylamine to its nitro and nitroso derivatives or N-phenylformamide to aniline.Solutions containing potassium tert-butoxide in place of superoxide produced the same products and oxygen was required for the reaction.Taken together, these results indicated that primary and secondary reducing aromatic amines are readily ionized by superoxide in aprotic solutions and then oxidized in a process involving molecular oxygen, leading to products whose structures suggest that processes such as radical recombination, N-oxidation, and N-demethylation have taken place.
- Stuehr, Dennis J.,Marletta, Michael A.
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- EPR and pulsed ENDOR study of intermediates from reactions of aromatic azides with group 13 metal trichlorides
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The reactions of group 13 metal trichlorides with aromatic azides were examined by CW EPR and pulsed ENDOR spectroscopies. Complex EPR spectra were obtained from reactions of aluminium, gallium and indium trichlorides with phenyl azides containing a variety of substituents. Analysis of the spectra showed that 4-methoxy-, 3-methoxy- and 2-methoxyphenyl azides all gave 'dimer' radical cations [ArNHC6H4NH2]+ and trimers [ArNHC6H4NHC6H4NH 2]+ followed by polymers. 4-Azidobenzonitrile, with its electron-withdrawing substituent, did not react. In general the aromatic azides appeared to react most rapidly with AlCl3 but this reagent tended to generate much polymer. InCl3 was the least reactive group 13 halide. DFT computations of the radical cations provided corroborating evidence and suggested that the unpaired electrons were accommodated in extensive π-delocalised orbitals. A mechanism to account for the reductive conversion of aromatic azides to the corresponding anilines and thence to the dimers and trimers is proposed.
- Bencivenni, Giorgio,Cesari, Riccardo,Nanni, Daniele,El Mkam, Hassane,Walton, John C.
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- Chitosan nanoparticles functionalized poly-2-hydroxyaniline supported CuO nanoparticles: An efficient heterogeneous and recyclable nanocatalyst for N-arylation of amines with phenylboronic acid at ambient temperature
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The present study aims to prepare an effective and eco-friendly nanocatalyst for the Chan–Lam coupling reaction of phenylboronic acid and amine in aerobic conditions. For this purpose, chitosan was extracted from shrimp shells waste by demineralization, deproteinization, and deacetylation processes and then converted to chitosan nanoparticles (CSN) by the ionic gelation with tripolyphosphate anions. Afterward, poly-2-hydroxyaniline (P2-HA) was grafted to chitosan nanoparticles (NPs) to employ as the support for CuO NPs. Characterization of the nanocatalyst was done using Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), mapping, energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The CuO NPs were identified in the spherical shape with an average size of 17 nm. The prepared nanocatalyst exhibited excellent catalytic performance with a high turnover number (TON) and turnover frequency (TOF) for the Chan–Lam coupling reaction of phenyl boronic acid and amines with different electronic properties. The prepared catalyst could be readily recovered and reused for at least five runs without any noticeable change in structure and catalytic performance. Chitosan (CS) was prepared via demineralization, deproteinization, and deacetylation of shrimp shell and chitosan nanoparticles (CSN) were prepared via ionic gelation process. Polymerization of 2-HA on the CSN surface was done to increase functional groups and create active sites for CuO NPs attachments. CuO NPs-P2-HA-CSN nanocomposite has been shown high efficiently for the Chan–Lam coupling reaction.
- Seyedi, Neda,Zahedifar, Mahboobeh
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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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- Electrochemical polymerization of aniline investigated using on-line electrochemistry/electrospray mass spectrometry
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A thin-layer electrochemical flow cell coupled on-line with electrospray mass spectrometry (EC/ES-MS) was used to investigate the soluble products from the controlled-potential anodic polymerization of aniline in H2O and H2O/CH3O H (1/1 v/v) with ammonium acetate and acetic acid or ammonium hydroxide as electrolytes (pH 4, 6.5, or 9). At a working electrode (glassy carbon) potential of 1.0 V versus Ag/AgCl, singly protonated aniline oligomers containing as many as 10 aniline units (10-mer) were observed in the ES mass spectra when the polymerization in H2O/CH3OH at pH 4 was carried out. The abundance of the higher n-mers decreased at higher solution pH and in 100% H2O at pH 4. Most of the oligomers were observed in more than one redox state ranging from fully oxidized (all imine nitrogens) to fully reduced (all amine nitrogens). The number of different redox states observed for the n-mers increased with increasing n. The structures of the reduced (m/z 185) and oxidized (m/z 183) aniline dimer ions (head-to-tail, tail-to- tail, or head-to-head) produced from the polymerization of aniline at pH 4, 6.5, and 9 in H2O/CH3OH were revealed to vary as a function of pH by comparison of their tandem mass spectrometry product ion spectra with the product ion spectra of the dimer standards. EC/ES-MS potential scan experiments, in which the working electrode current and major n-mer ions for n = 2, 3, and 4 were monitored as a function of electrode potential, were used to probe the growth mechanism to higher aniline oligomers. Under the conditions used, the controlled-current electrolytic process inherent to the operation of the ES ion source did not significantly influence the formation or nature of the oligomers observed. Beyond the current application, the results presented here serve to demonstrate the utility of EC/ES-MS as a tool in identifying the initial products of electropolymerization and in studying the products of electrode reactions in general.
- Deng, Haiteng,Van Berkel, Gary J.
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- CoII immobilized on an aminated magnetic metal-organic framework catalyzed C-N and C-S bond forming reactions: A journey for the mild and efficient synthesis of arylamines and arylsulfides
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In this work, we report a simple and versatile method for the modification of a metal-organic framework (NH2-MIL53(Al)) in a step-wise manner. To characterize the synthesized nanostructured catalyst, a variety of spectroscopic and microscopic techniques including FT-IR, XRD, BET, TEM, FE-SEM, EDX, EDX-mapping, TGA, XPS, VSM, ICP-OES and CHN have been employed. Fe3O4@AMCA-MIL53(Al)-NH2-CoII NPs, which benefit from small nanocrystalline size (10-30 nm, according to the XRD and TEM data) in combination with the coexistence of magnetic nanoparticles, a metal-organic framework, and cobalt species, were found to be an excellent environment catalyst to promote the C-N and C-S cross coupling reactions. A wide range of functional substrates including electron-withdrawing and electron-donating aryl halides underwent the coupling reaction with aromatic/heteroaromatic/benzylic and aliphatic amines and sulfides. The results demonstrated that the yields of the target products were good to excellent and the catalyst can be recycled for at least seven recycling runs without a discernible decrease in its catalytic activity. Furthermore, the heterogeneity studies (such as hot filtration and poisoning tests) efficiently confirmed that the as-synthesized nanostructured catalyst is heterogeneous and completely stable under the reaction conditions. We hope that our study inspires more interest in designing novel catalysts based on using low-cost metal ions (such as cobalt) in the field of cross coupling reactions.
- Mohammadinezhad, Arezou,Akhlaghinia, Batool
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- Kinetics of the p-aminodiphenylamine radical in organic solution: An electrochemical and electron spin resonance study
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In studying the reaction mechanism of anodic aniline oxidation the dimer p-aminodiphenylamine (ADPA) was found to be the main intermediate product in acidic solution. It is oxidized in both the free amine and the protonated form. The cyclic voltammograms have been simulated by taking into account an electrochemical reaction of both the protonated and the nonprotonated forms. Thus, it was also found that the ADPA concentration is determined by the protonation equilibrium. The oxidation product N-phenylquinone diimine (PQDI) undergoes a symproportionation reaction with ADPA forming the ADPA?+ cation radical. The equilibrium constant for this reaction of PQDI in dimethyl sulfoxide was determined and found to be independent of the concentration of the protons in solution. The ADPA?+ cation radical decay can be described by a rate equation based on a second-order reaction for the radical dimerization and a pre-equilibrium for the radical formation by symproportionation. The reaction mechanisms of the anodic oxidation of p-aminodiphenylamine and its chemical follow-up reactions are given.
- Petr,Dunsch
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- Cu(OAc)2-porphyrins as an efficient catalytic system for base-free, nature mimicking Chan–Lam coupling in water
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The use of porphyrins as ligands in organic synthesis reveals the natural process, because these are the constituent motifs of catalysts in many bio-organic reactions. This article presents the synthesis of two N-pincer tetradentate porphyrins; tetrasodium meso-tetra(p-sulfonatophenyl)phorphyrin (H2TSTpSPP) and meso-tetra(m-carboxyphenyl)porphyrin (H2TmCPP), and study on their aptness for Cu-catalyzed C–N coupling reactions of arylboronic acids and amines (Chan–Lam coupling reaction) in water under external base free conditions. The porphyrins and Chan–Lam coupling products were well characterized by their spectral analysis. The high product yields, application of nature-inspired conditions, large extent of substrates, ease of making and handling the ligands, avoidance of base, and use of water as reaction media are the attractive attributes of this finding.
- Venkateswarlu, Katta,Rao, Kanusu Umamaheswara
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- Para -Selective copper-catalyzed C(sp2)-H amidation/dimerization of anilides via a radical pathway
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Copper-catalyzed amidation/dimerization of anilides via regioselective C(sp2)-H functionalization is achieved. The para-selective amidation is accomplished on the anilide aromatic ring via a radical pathway leading to C-N bond formation in the presence of ammonium persulfate as a radical source/oxidant for the copper catalyst. The developed protocol tolerates a wide range of anilide substrates. The regioselectivity is confirmed by single-crystal X-ray studies.
- Viveki, Amol B.,Garad, Dnyaneshwar N.,Gonnade, Rajesh G.,Mhaske, Santosh B.
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p. 1565 - 1568
(2020/02/13)
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- Substituted anilino-benzothiazole-2-thioketone compound as well as preparation method and application thereof
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The invention discloses a substituted anilino-benzothiazole-2-thioketone compound and a preparation method thereof. In addition, the invention also relates to an application of the compound in rubberproducts. The substituted anilino-benzothiazole-2-thioketone compound disclosed by the invention not only can promote rubber vulcanization, but also can prolong the service life of the rubber products.
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- Direct conversion of phenols into primary anilines with hydrazine catalyzed by palladium
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Primary anilines are essential building blocks to synthesize various pharmaceuticals, agrochemicals, pigments, electronic materials, and others. To date, the syntheses of primary anilines mostly rely on the reduction of nitroarenes or the transition-metal-catalyzed Ullmann, Buchwald-Hartwig and Chan-Lam cross-coupling reactions with ammonia, in which non-renewable petroleum-based chemicals are typically used as feedstocks via multiple step syntheses. A long-standing scientific challenge is to synthesize various primary anilines directly from renewable sources. Herein, we report a general method to directly convert a broad range of phenols into the corresponding primary anilines with the cheap and widely available hydrazine as both amine and hydride sources with simple Pd/C as the catalyst.
- Qiu, Zihang,Lv, Leiyang,Li, Jianbin,Li, Chen-Chen,Li, Chao-Jun
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p. 4775 - 4781
(2019/05/16)
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- One-pot propagation of (Hetero)Arylamines: Modular synthesis of diverse Amino-di(hetero)arylamines
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Formal propagation of (hetero)arylamine is achieved via a one-pot Buchwald–Hartwig C–N cross-coupling and nitro reduction sequence, enabling a rapid modular synthesis of diverse amino-di(hetero)arylamines from (hetero)arylamines and halogenated nitrobenzenes. Various functionalized aromatic amines with different electronic and steric environments can be efficiently prolongated to formally incorporate another arylamino fragments. This approach has been successfully applied in the synthesis of more than forty amino-di(hetero)arylamines. The applicability of this method has also been demonstrated in the synthesis of oligoanilines and the tyrosine-kinase inhibitor Imatinib.
- Liang, Xueting,Xu, Liang,Li, Cuihua,Jia, Xin,Wei, Yu
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p. 721 - 731
(2019/01/08)
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- Synthesis of Di(hetero)arylamines from Nitrosoarenes and Boronic Acids: A General, Mild, and Transition-Metal-Free Coupling
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The synthesis of di(hetero)arylamines by a transition-metal-free cross-coupling between nitrosoarenes and boronic acids is reported. The procedure is experimentally simple, fast, mild, and scalable and has a wide functional group tolerance, including carbonyls, nitro, halogens, free OH and NH groups. It also permits the synthesis of sterically hindered compounds.
- Roscales, Silvia,Csák?, Aurelio G.
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supporting information
p. 1667 - 1671
(2018/03/23)
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- Method for continuously preparing p-aminodiphenylamine
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The invention provides a method for preparing p-aminodiphenylamine through continuous catalysis. According to the method, 4-nitrodiphenylamine and 4-nitrosodiphenylamine are used as raw materials andsubjected to continuous reduction in the presence of an organic solvent under the catalysis of a supported catalyst so as to obtain p-aminodiphenylamine. The method of the invention solves the problems of environmental pollution, low catalyst activity, difficult catalyst recovery and high labor intensity in the prior art.
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Paragraph 0017; 0018; 0019; 0020; 0021; 0022
(2018/11/03)
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- Preparation method for 4-aminodiphenylamine
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The invention provides a preparation method for 4-aminodiphenylamine, which includes the following steps: A) a condensation reaction: performing the condensation reaction to aniline and nitrobenzene under the effect of a catalyst system to obtain an intermediate mixture, wherein the catalyst system comprises an alkaline ionic solution and tetraalkyl ammonium hydroxide; B) separation to the catalyst system: adding water to the intermediate mixture, and allowing the mixture to stand for layering the mixture to obtain an upper intermediate-organic phase and a lower catalyst-water phase; and C) hydrogenation reaction: hydrogenating the upper intermediate-organic phase to prepare the 4-aminodiphenylamine. The preparation method solves a technical problem of introduction of impurities when the catalyst tetraalkyl ammonium hydroxide is heated and decomposed during the hydrogenation reduction step, but also increases the recycle rate of the catalyst in the condensation step, reduces use amount of a hydrogenation solvent in the hydrogenation step and improves selectivity of a hydrogenation catalyst in the hydrogenation step by means of separation to the catalyst tetraalkyl ammonium hydroxide before the hydrogenation step.
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Paragraph 0054; 0055
(2016/10/31)
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- CoPc/Cu(OAc)2-catalyzed N-arylation of amines with arylhydrazines leading to N-aryl amines
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The N-arylation of amines with arylhydrazines has been developed, achieving the selective cross-coupling of aryl radicals with amines to form N-aryl amines. The reaction uses air as an oxidant, CoPc and Cu(OAc)2as catalysts. The reaction proceeds under mild conditions in air through a relay process, arylhydrazines are oxidized to aryldiazenes by CoPc, further oxidized to aryl radicals by air (O2), which are trapped by Cu(OAc)2–amine complex, followed by reduction–elimination reaction to form N-aryl amines. Arylamines and arylhydrazines give the highest yields, but N-aryl-N-alkylamines and N-alkylamines can be used as well.
- Sun, Wang-Bin,Zhang, Pei-Zhi,Jiang, Tao,Li, Cheng-Kun,An, Li-Tao,Shoberu, Adedamola,Zou, Jian-Ping
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p. 6477 - 6483
(2016/09/23)
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- A method for preparing aromatic amine derivative
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The invention discloses a preparation method of a diarylamine ramification. The preparation method comprises the following steps: dissolving a phenylamine ramification, a phenylhydrazine ramification, a metal phthalocyanine ramification and a copper salt into a solvent, and reacting at -10 to 40 DEG C to obtain the diarylamine ramification. According to the preparation method, the phenylamine ramification and the phenylhydrazine ramification are taken as starting materials, so that raw materials are easy to obtain and plenty in variety; a product obtained by utilizing the method is plenty in type, can not only be directly used, but also be used for other further reactions; and no additive is required to be added. The preparation method disclosed by the invention has the advantages of short synthetic route, moderation in reaction condition, simple reaction operation and post-processing process, high yield and suitability for large-scale production.
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Paragraph 0086-0089
(2016/10/08)
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- A 4-aminodiphenylamine catalytic hydrogenation of the apparatus and process for the production of
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The invention relates to a device and process for producing 4-aminodiphenylamine by catalytic hydrogenation. The 4-aminodiphenylamine is prepared from materials by catalytic hydrogenation in a continuous production device consisting of a highly efficient tubular reactor and corresponding equipment without participation of a solvent under a fully closed state via reasonable process steps in the presence of a relatively inexpensive and easily available Raney nickel catalyst by selecting a highly efficient gas, liquid, solid catalytic hydrogenation tubular reactor. According to the device and process disclosed by the invention, the consumption of the Raney nickel catalyst is less than 0.1%, the conversion rate can reach 100%, the selectivity is 99.5% or more and the yield is above 99.8%.
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Paragraph 0035-0036; 0038-0039
(2017/03/22)
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- PROCESS FOR THE PREPARATION OF 4-AMINODIPHENYLAMINE PRECURSORS
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Process for the preparation of 4-aminodiphenylamine precursors by reacting aniline and nitrobenzene in the presence of water and a base, with controlled amount of water with respect to the base, characterised in that the mole ratio of water to the dosed base, obtained after extraction of organic impurities by an aromatic solvent of an aqueous phase from hydrogenation of a condensation mixture, is between 3.99 and 3:1 at the start of the coupling reaction, and between 0.40 and 0.59:1 at the end of the coupling reaction, and the end of the coupling reaction is indicated by full conversion of nitrobenzene or by achieving the maximum content 2 wt. % of the initial amount of nitrobenzene in the reaction mixture. The ingredients are continuously fed into reactor cascades in the required ratio to the condensation process, the mole ratio of aniline to nitrobenzene is between 1 :1 and 10:1, and hydrogenation of the condensation product in the presence of a hydrogenation catalyst and added water is followed by separation of the hydrogenation catalyst, and an organic phase, containing 4-aminodiphenylamine, is separated from the aqueous phase, containing the released base.
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Page/Page column 5; 6
(2015/07/07)
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- IMPROVED PROCESS FOR PREPARING 4-AMINODIPHENYLAMINE
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A process for preparing 4-aminodiphenylamine (4-ADPA) comprising steps of coupling of aniline with nitrobenzene in presence of a suitable base, e.g. tetramethylammonium hydroxide (TMAH), hydrogenation of the coupling mass, phase separation, hydrogenation of azobenzene in the separated organic mass and fractional distillation for 4-ADPA recovery. An improvement in 4-ADPA recovery and a lowering of tar formation are obtained due to azobenzene reduction prior to 4-ADPA isolation. Also a gain in volume productivity of 4-ADPA is obtained by suitably altering the batch cycle time of the coupling reaction.
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Page/Page column 20
(2013/09/26)
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- SYNTHESIS SYSTEM, RUBBER CHEMICAL SUBSTANCE FOR TIRES, SYNTHETIC RUBBER FOR TIRES, AND PNEUMATIC TIRE
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The present invention provides a synthesis system that can synthesize aniline and/or styrene efficiently, a synthesis system that can synthesize butadiene (1,3-butadiene) efficiently, a rubber chemical for a tire which is synthesized from the aniline obtained by the synthesis system, a synthetic rubber for a tire which is synthesized from the styrene and/or butadiene obtained by the synthesis systems, and a pneumatic tire produced using the rubber chemical for a tire and/or the synthetic rubber for a tire. The present invention relates to a synthesis system for synthesizing aniline and/or styrene from an alcohol having two or more carbon atoms via an aromatic compound.
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- AN EFFICIENT CONTINUOUS PROCESS FOR MANUFACTURING OF 4-AMINODIPHENYLAMINE FROM ANILINE AND NITROBENZENE
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An efficient continuous manufacturing process for 4-aminodiphenylamine by coupling aniline with nitrobenzene in the presence of tetramethylammonium hydroxide (TMAH) as a base, using flow reactors wherein base decomposition is considerably reduced by optimizing base quantity, process conditions and process equipment. Accordingly, in brief summary, one embodiment of the present invention is a process which comprises one or more of the steps of reacting aniline and nitrobenzene in the presence of water and TMAH as a base, in a continuous manner by feeding the reactants to a series of continuous flow reactors, while continuously distilling off an aniline-water mixture under, reduced pressure such that the water to total base molar ratio is less than 0.6:1 at the flow reactors outlet, and the water to unbound TMAH molar ratio is about 4: 1 in the reaction product.
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Page/Page column 20-21
(2013/11/05)
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- EPR and ENDOR spectroscopic study of the reactions of aromatic azides with gallium trichloride
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The reactions of gallium trichloride with phenyl and deuterio-phenyl azides, as well as with 4-methoxyphenyl azide and deuterium isotopomers, were examined by product analysis, CW EPR spectroscopy and pulsed ENDOR spectroscopy. The products included the corresponding anilines together with 4-aminodiphenylamine type dimers, and polyanilines. Complex CW EPR spectra of the radical cations of the dimers [ArNHC6H4NH 2]+ and trimers [ArNHC6H4NHC 6H4NH2]+ were obtained. These EPR spectra were analysed with the help of data from the deuterium-substituted analogues as well as the pulse Davies ENDOR spectra. DFT computations of the radical cations provided corroborating evidence and suggested the unpaired electrons were accommodated in extensive π-delocalised orbitals. A mechanism to account for the reductive conversion of aromatic azides to the corresponding anilines and thence to the dimers and trimers is proposed.
- Bencivenni, Giorgio,Cesari, Riccardo,Nanni, Daniele,El Mkami, Hassane,Walton, John C.
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supporting information; experimental part
p. 5097 - 5104
(2010/12/24)
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- NOVEL PIPERAZINE DERIVATIVES AS INHIBITORS OF STEAROYL-CoA DESATURASE
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The present invention relates to piperazine derivatives that act as inhibitors of stearoyl-CoA desaturase. The invention also relates to methods of preparing the compounds, compositions containing the compounds, and to methods of treatment using the compounds.
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Page/Page column 28
(2009/10/01)
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- 3-HYDROXYISOTHIAZOLE-4-CARBOXAMIDINE DERIVATIVES AS CHK2 INHIBITORS
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This invention provides compounds of Formula (I), which are inhibitors of Chk2 and are useful as a radiation protection agents in anticancer radiotherapy. A method of modulating Chk2 in vitro includes treating a substrate with Chk2 in the presence of compounds of formula I. A method of making a compound of formula I includes: a) forming a biaryl amine having an amino (NH2) group; b) converting the amino group to an isothiocyanate group; c) adding a cyanoacetamide to said isothiocyanate group to form a thioamide adduct; d) cyclizing said thioamide adduct to form an isothiazole having a cyano group; and e) adding an amine to said cyano group to form a carboxamidine group.
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Page/Page column 11-12
(2009/01/23)
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- METHOD FOR PREPARING 4-AMINODIPHENYLAMINE
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4-aminodiphenylamine is prepared by reacting carbanilide and nitrobenzene in an adequate solvent, which may be nitrobenzene, in the presence of an appropriate organic base, which may be tetramethylammonium hydroxide, alone or in mixture with an inorganic base and subsequently reducing the reaction product in the presence of an appropriate catalyst and hydrogen gas. The subsequent reduction may be carried out on the reaction mixture before the reaction mixture is subjected to separation.
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Page/Page column 5
(2008/06/13)
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- METHOD FOR PREPARING 4-AMINODIPHENYLAMINE
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The present invention relates to a method for preparing 4-aminodiphenylamine comprising the steps of reacting carbanilide and nitrobenzene in an adequate solvent in the presence of an appropriate organic base or a mixture of an organic base and an inorganic base and subsequently reducing the reaction product, or a 4-aminodiphenylamine intermediate, without separation from the reaction mixture, in the presence of an appropriate catalyst and hydrogen gas. Because the method of the present invention uses carbanilide as starting material, which reacts directly with nitrobenzene with high reactivity and selectivity, generation of by-products such as phenazine and 2-nitrodiphenylamine can be reduced and the 4-aminodiphenylamine intermediate can be prepared with good selectivity and production yield. Also, because a recyclable organic base is used, amount of wasted material can be minimized and 4-aminodiphenylamine, or the final product, can be prepared efficiently, without the separation of 4-aminodiphenylamine intermediate for the subsequent reduction process. In addition, in comparison with conventional preparation methods of 4-aminodiphenylamine, generation of harmful wastes can be significantly reduced and environment-damaging corrosive materials are not generated.
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Page/Page column 9
(2008/06/13)
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- Process for preparing 4-aminodiphenylamine
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The present invention discloses a process for preparing 4-aminodiphenylamine, which process uses nitrobenzene and aniline as raw materials, a complex base catalyst as condensation catalyst and a powdery composite catalyst as hydrogenation catalyst, and comprises five process stages: condensation; separation I; hydrogenation; separation II; and refining. The process can be continuously carried out. By selecting a complex base catalyst to catalyze the condensation reaction and separating it prior to the hydrogenation, the problem that the complex base catalysts thermally decompose in the hydrogenation reaction is avoided, the selectable range of hydrogenation catalysts is largely enlarged so that it is possible to select cheaper hydrogenation catalyst, and the selection of production process and equipment is easier and further industrialization is easier. The complex base catalysts used in the present invention are inexpensive and have higher catalytic activity. The process can be carried out at mild conditions and can adapt to broad range of water content, by-product is less and conversion and selectivity are higher. The operational strength is low, no corrosive liquid is produced, and environment pollution is reduced. The purity of 4-aminodiphenylamine prepared can exceed 99 wt.-%, and the yield in the industrial production process can be over 95%.
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Page/Page column 13
(2008/06/13)
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- 1,3-Dihydroxybenzene derivatives and colorants containing said compounds
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1,3-Dihydroxybenzene derivatives of general formula (I) or (Ia) or physiologically tolerated, water-soluble thereof wherein R′1 denotes substituted pyridyl group, a pyrimidyl group, a group of formula (IIa) or (IIIa) and the dyeing agents for keratin fibers containing these compounds.
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- One step hair coloring compositions using salts
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A hair coloring composition comprising the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an amino phenol, a naphthol, a polyhydric phenol, a catechol and mixtures thereof; wherein the composition comprising one or more oxidative hair coloring agents further comprises al least one water soluble carbonate releasing salts; and optionally a water soluble ammonium salt, is described.
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- PROCESS FOR PREPARING ORTHO SUBSTITUTED PHENYLAMINES
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A process is disclosed for preparing ortho substituted phenylamines comprising contacting phenylhydroxylamine, optionally substituted with at least one inert substituent, with a nucleophilic reagent in the presence of a manganese oxide at a temperature between about 10°C and about 170°C and a pressure from subatmospheric to superatmospheric such that an ortho substituted phenylamine, optionally correspondingly substituted with at least one inert substituent, is predominantly formed.
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- Process for the preparation of aminodiphenylamines
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Die Erfindung betrifft ein Verfahren zur Herstellung von Aminodiphenylaminen, insbesondere von 4-Aminodiphenylamin (4-ADPA), durch Umsetzung von Nitrohalogenbenzolen mit Anilinen in Gegenwart einer Base sowie eines Kupfer-Phosphor-Komplexes und anschlie?ender Hydrierung der intermedi?r gebildeten Nitrodiphenylaminen.
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- THE METHOD FOR PREPARING 4-NITRODIPHENYLAMINE AND 4-NITROSODIPHENYLAMINE FROM CARBANILIDE
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This invention relates to a process for preparing 4-nitrodiphenylamine and 4-nitrosodiphenylamine to be used for 4-aminodiphenylamine as an intermediate of antiozonant, wherein carbanilide is reacted with nitrobenzene in the presence of an appropriate base, while simultaneously adding aniline to the mixture so as to regenerate some amounts of carbanilide as a starting material. According to this invention, 4-nitrodiphenylamine and 4-nitrosodiphenylamine can be prepared in a higher selectivity and conversion rate via a continuous reaction by recycling carbanilide, a starting material, while adding a certain amount of aniline during the process. Further, the amount of waste water can be significantly reduced compared to the conventional method without any corrosive materials harmful to the environment.
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- Transition metal complexes as dye forming catalysts in hair coloring compositions
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A hair coloring composition comprising a first composition which comprises: (a) a dye forming transition metal salt or complex; which is first applied to the hair; and a second composition which comprises the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an aminophenol, a polyhydric phenol a catechol and mixtures thereof.
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- Method of preparation of 4-aminodiphenylamine
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A method of preparing 4-aminodiphylamine through an intermediate preparation of 4-nitrodiphenylamine and/or 4-nitrosodiphenylamine and/or their salts by reaction of aniline with nitobenzene in a liquid medium at a temperature of 50 to 130° C., under normal or reduced pressure, in an inert atmosphere or in the presence of air oxygen, with subsequent hydrogenation of an intermediate of 4-nitrodiphenlyamine and/or nitrosodiphenylamine and side products, and by isolation of 4-aminodiphenylamine and the side products of unconverted raw materials
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- Method of preparation of 4-aminodiphenylamine
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A method of preparing 4-aminodiphylamine through an intermediate preparation of 4-nitrodiphenylamine and/or 4-nitrosodiphenylamine and/or their salts by reaction of aniline with nitobenzene in a liquid medium at a temperature of 50 to 130° C., under normal or reduced pressure, in an inert atmosphere or in the presence of air oxygen, with subsequent hydrogenation of an intermediate of 4-nitrodiphenylamine and/or nitrosodiphenylamine and side products, and by isolation of 4-aminodiphenylamine and the side products of unconverted raw materials.
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Page column 13
(2008/06/13)
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- Process for producing aminodiphenylamines
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The present invention relates to the production of aminodiphenyl-amines resulting in good yields and high purity levels when aromatic amines are reacted with nitrohalobenzenes in the presence of a palladium catalyst and a base and the product thus obtained is subsequently hydrogenated with hydrogen.
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- Preparation of substituted aromatic amines
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A method for producing aromatic amines such as N-phenyl-p-phenylenediamine is disclosed wherein an amine substituted aromatic such as aniline is oxidized with oxygen or hydrogen peroxide in the presence of a preferred trisodium pentacyano ferrate(II) complex containing various water soluble ligands, such as ammonia, mono alkyl amine, dialkyl amines, and trialkyl amines. The complex is subsequently catalytically reduced by hydrogenation using certain heterogeneous metal catalysts to yield the desired aromatic amine.
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- Process for dyeing keratinous fibers with aminoindoles and oxidation dye precursors at basic Ph's and dyeing agents
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The invention relates to a process for dyeing keratinous fibres, which consists in applying to these fibres a composition containing, in a suitable medium for dyeing, at least one coupler of formula: STR1 where R1 denotes hydrogen or alkyl, R2 and R3 denote hydrogen, alkyl, COOR' where R' is alkyl or hydrogen, at least one of the groups R2 and R3 denoting hydrogen, R4 denotes hydrogen, alkyl, hydroxyalkyl, polyhydroxyalkyl or aminoalkyl, Z1 and Z2 denote hydrogen, alkyl, hydroxyl, halogen, alkoxy, at least one of the groups Z1 and Z2 is other than hydrogen at least one oxidation dye precursor, at least one oxidizing agent, the pH of the composition applied to the fibres being higher than 7.
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- Preparation of substituted aromatic amines
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A method for producing aromatic amines such as N-phenyl-p-phenylenediamine is disclosed wherein an amine substituted aromatic such as aniline is oxidized with oxygen or hydrogen peroxide in the presence of trisodium pentacyano ferrate(II) complexes containing various water soluble ligands, such as ammonia, mono alkyl amine, dialkyl amines, and trialkyl amines. The complex is subsequently catalytically reduced by hydrogenation using certain heterogeneous metal catalysts to yield the desired aromatic amine.
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- Methods for dyeing keratinous fibers with compositions which contain aminoindole couplers, oxidation dye precursors, and oxidizing agents at acid pHs
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A method for dyeing keratin fibers, wherein a composition is applied to said fibers which contains, in a suitable dyeing medium, at least one coupler having formula (I) STR1 wherein R1 is hydrogen or alkyl; R2 and R3 are hydrogen, alkyl, COOR', where R' is alkyl or hydrogen; R4 is hydrogen, hydroxyalkyl, alkyl, polyhydroxyalkyl or acetyl or aminoalkyl wherein the amine may be mono- or disubstituted by alkyl; Z1 and Z2 are hydrogen, alkyl, hydroxy, halogen, alkoxy or a salt thereof; at least one precursor of an oxidation hair dye; and at least one oxidizing agent, the pH of the composition applied to the fibers being less than 7.
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- Process for preparing para-phenylenediamine derivatives
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An improvement in a process for the preparation of a p-aminodiarylamine by reduction of the corresponding nitroso or nitro compound with hydrogen in a hydrogenator in the presence of a catalyst is disclosed. The invention includes equipping the hydrogenator with filtration means capable of separating the p-aminodiarylamine product from the catalyst, whereby the p-aminodiarylamine product can be removed from the hydrogenator while the catalyst is retained therein, thereby permitting the reaction to be run semicontinuously or continuously.
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- 3-substituted para-aminophenols
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The invention concerns the use of a 3-substituted para-aminophenol as an oxidation dye precursor for dyeing keratinous fibres, in particular human hair. The 3-substituted para-aminophenol has formula: STR1 where R1 represents alkyl, alkenyl, mono- or polyhydroxyalkyl, nitrile, cyanoalkyl, halogenoalkyl, aminoalkyl or alkoxyalkyl and R2 represents hydrogen, alkyl or mono- or polyhydroxyalkyl, provided that when R2 is hydrogen R1 is not methyl or trifluoromethyl, and to addition salts thereof with an acid. The invention also concerns dye compositions containing compound (I). The invention further concerns novel 3-substituted para-aminophenols.
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- The photoreactivity of p-Chloroaniline
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p-Chloroaniline (pCA) shows the highest photoreactivity among all isomers of haloanilines. For the elucidation of complex mechanism of pCA photolysis the identification of final products was performed, and the influence of the medium on absorption, fluorescence and products formation was studied. Benzidine was identified besides aniline among the secondary photoproducts. This fact suggests the formation of 4-iminocyclohexa-2,5-dienylidene as transient species.
- Szczepanik,Latowski
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p. 807 - 815
(2007/10/03)
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- Process for preparing substituted aromatic azo compounds
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A process for preparing substituted aromatic azo compounds is provided which comprises contacting a nucleophilic compound and an azo containing compound in the presence of a suitable solvent system, and reacting the nucleophilic compound and the azo containing compound in the presence of a suitable base and a controlled amount of protic material at a temperature of about 10° C. to about 150° C. in a confined reaction zone wherein the molar ratio of protic material to base is 0:1 to about 5:1.
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