- Method for synthesizing 2, 5-dichloroaniline by kettle-type continuous hydrogenation
-
The invention provides a method for synthesizing 2, 5-dichloroaniline by kettle-type continuous hydrogenation. The method involves a feeding pump, a preheater, a reactor, a gas-liquid separator and anextraction pump, the feeding pump, the preheater, the reactor, the gas-liquid separator and the extraction pump are sequentially connected in series, and a plurality of hydrogen distribution pipes are arranged in the reactor, a plurality of through holes are formed in the side surface of the hydrogen distribution pipes, and a catalyst is arranged in the hydrogen distribution pipes; the method forsynthesizing 2, 5-dichloroaniline through kettle-type continuous hydrogenation comprises the following steps of: inputting a 2, 5-dichloronitrobenzene solution into the reactor through the feeding pump, inputting hydrogen into the reactor, adsorbing the hydrogen through the catalyst, and then reacting the hydrogen with the 2, 5-dichloronitrobenzene solution to generate 2, 5-dichloroaniline; by adopting the catalyst with high nitro-reduction activity, byproducts are few, and efficient conversion of the raw materials can be realized only at a reaction temperature of 50-80DEG C. By adopting themethod to continuously react for 720 hours, the raw material conversion rate is greater than 95%, and the product selectivity is greater than 95%.
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-
Paragraph 0024-0033
(2021/03/13)
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- Fabrication of magnetically separable ruthenium nanoparticles decorated on channelled silica microspheres: Efficient catalysts for chemoselective hydrogenation of nitroarenes
-
Fe3O4-SiO2microspheres were synthesized by a three-step synthetic procedure involving silica coating, surface capping, and surface modification. These magnetic mesoporous microspheres were employed as sorbents for the incorporation of ultrasmall Ru nanoparticles (2-5 nm) followed by thermal aggregation of the microspheres for achieving better heterogeneity and low leaching. The Ru decorated Fe3O4-SiO2microspheres (Ru@Fe3O4-CSM) were applied as chemoselective catalysts to convert more than 20 substituted nitroarenes to corresponding amines with good-to-excellent conversion (77-99%) and selectivity (70-100%) under mild conditions; the catalyst can be magnetically recovered within a frame of 90s (recovery time-lapse) and reused up to 5 times without significant decrease in activity or selectivity. Magnetic hysteresis studies were performed to elucidate the magnetic behavior of the ruthenium decorated materials.
- Das, Manash R.,Das, Pankaj,Kalita, Gauravjyoti D.
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p. 13483 - 13496
(2021/10/12)
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- A mild and selective Cu(II) salts-catalyzed reduction of nitro, azo, azoxy, N-aryl hydroxylamine, nitroso, acid halide, ester, and azide compounds using hydrogen surrogacy of sodium borohydride
-
The first mild, in situ, single-pot, high-yielding well-screened copper (II) salt-based catalyst system utilizing the hydrogen surrogacy of sodium borohydride for selective hydrogenation of a broad range of nitro substrates into the corresponding amine under habitancy of water or methanol like green solvents have been described. Moreover, this catalytic system can also activate various functional groups for hydride reduction within prompted time, with low catalyst-loading, without any requirement of high pressure or molecular hydrogen supply. Notably, this system explores a great potential to substitute expensive traditional hydrogenation methodologies and thus offers a greener and simple hydrogenative strategy in the field of organic synthesis.
- Kalola, Anirudhdha G.,Prasad, Pratibha,Mokariya, Jaydeep A.,Patel, Manish P.
-
supporting information
p. 3565 - 3589
(2021/10/12)
-
- Commercially Available CuO Catalyzed Hydrogenation of Nitroarenes Using Ammonia Borane as a Hydrogen Source
-
Tandem ammonia borane dehydrogenation and nitroarenes hydrogenation has been reported as a novel strategy for the preparation of aromatic amines. However, the practical application of this strategy is subjected to the high-cost and tedious preparation of supported noble metal nanocatalysts. The commercially available CuO powder is herein demonstrated to be a robust catalyst for hydrogenation of nitroarenes using ammonia borane as a hydrogen source under mild conditions. Numerous amines (even sterically hindered, halogenated, and diamines) could be obtained through this method. This monometallic catalyst is characteristic of support-free, excellent chemoselectivity, low-cost, and high recyclability, which will favor its future utilization in preparative reduction chemistry. Mechanistic studies are also carried out to clarify that diazene and azoxybenzene are key intermediates of this heterogeneous reduction.
- Du, Jialei,Chen, Jie,Xia, Hehuan,Zhao, Yiwei,Wang, Fang,Liu, Hong,Zhou, Weijia,Wang, Bin
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p. 2426 - 2430
(2020/03/30)
-
- A new process to prepare 3,6-dichloro-2-hydroxybenzoic acid, the penultimate intermediate in the synthesis of herbicide dicamba
-
Glyphosate [N-(phosphonomethyl)glycine] is a broad spectrum, post-emergent herbicide that is among the most widely used agrochemicals globally. Over the past 30 years, there has been a development of glyphosate-resistant weeds, which pose a significant challenge to growers and crop scientists, resulting in lower crop yields and increased costs. 3,6-Dichloro-2-methoxybenzoic acid (dicamba) is the active ingredient in XtendiMax a standalone herbicide developed by Bayer Crop Science to control broadleaf weeds, including glyphosate-resistant species. 3,6-Dichloro-2-hydroxybenzoic acid (3,6-DCSA) is the penultimate intermediate in the synthesis of dicamba. Existing dicamba manufacturing routes utilize a high temperature, high pressure Kolbe-Schmitt carboxylation to prepare 3,6-DCSA. Described in this Letter is a new, non-Kolbe-Schmitt process to prepare 3,6-DCSA from salicylic acid in four chemical steps.
- Walker, Daniel P.,Harris, G. Davis,Carroll, Jeffery N.,Boehm, Terri L.,McReynolds, Matthew D.,Struble, Justin R.,van Herpt, Jochem,van Zwieten, Don,Koeller, Kevin J.,Bore, Mangesh
-
p. 1032 - 1036
(2019/03/17)
-
- Catalytic hydrogenation process of chlorine-containing nitro aromatic compound
-
The invention discloses a catalytic hydrogenation process of a chlorine-containing nitro aromatic compound. The specific process comprises the following steps: adding a chlorine-containing nitrobenzene, water and an anti-dechlorination agent into a reactor, carrying out mixing by stirring, then adding a catalyst and a self-prepared cocatalyst, introducing nitrogen into the reactor for 5-10 min toreplace air in the reactor, then introducing hydrogen until the pressure is 18-26 kg, carrying out a reaction at 55-75 DEG C for 1-3 hours, carrying out cooling to room temperature after the reactionis finished, and detecting the content of the target product in the obtained product. The process conditions are mild, the effect of the reaction substrate on the catalyst is small, the catalytic activity is high, and the yield of the product is high.
- -
-
Paragraph 0024; 0025; 0026; 0027
(2018/11/27)
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- Preparation method of 2,5-dichloroaniline
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The invention provides a preparation method of 2,5-dichloroaniline, and belongs to the field of compound preparation. Under the effects of oxidizing agents, aminating agents, metal complex catalysts and cocatalysts, 1,4-dichlorobenzene is used as raw materials; one from water, methanol, acetonitrile, acetic acid and ethyl alcohol or a composition of more than one in water, methanol, acetonitrile, acetic acid and ethyl alcohol is used as a solvent; reaction is carried out at the reaction temperature being 15 to 95 DEG C for 1 to 96h to obtain 2,5-dichloroaniline. The method provided by the invention has the advantages that the catalyst system has high oxidative amination reaction efficiency and high yield; the reaction conditions are relatively mild; the side reaction is little; products can be conveniently separated; the reaction time is greatly shortened; the preparation method can be popularized to large-scale industrial production.
- -
-
Paragraph 0022; 0024-0076
(2017/08/29)
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- Method for synthesizing 2,5-dichloroaniline by micro-channel reactor
-
The invention provides a method for synthesizing 2,5-dichloroaniline by a micro-channel reactor. A nitratlon reaction and a catalytic hydrogenation reaction are performed by using the micro-channel reactor. The method comprises the following steps of nitratlon reaction: raw materials of nitro-p-dichlorobenzene are dissolved into an organic solvent, and are preheated; concentrated nitric acid and concentrated sulfuric acid are mixed and are preheated; the materials enter a reaction module group to take a reaction after the preheating; and an intermediate product of 2,5-Dichloronitrobenzene is obtained after the refining; and catalytic hydrogenation reaction: the 2,5-Dichloronitrobenzene is dissolved into a solvent; Pd-loaded active carbon catalysts are added; dechlorination inhibitors are added, and then, preheating is performed; after the materials are preheated, hydrogen gas enters the reaction module group to take a reaction; and post-treatment is performed to obtain the 2,5-dichloroaniline. The method provided by the invention has the advantages that the mixing effect is good; the temperature and material proportion control is precise; the reaction yield and the product purity are improved; the reaction is safe and stable; the time is short; no amplification effect exists; and wide application prospects are realized in industrial production.
- -
-
Paragraph 0044; 0049; 0055; 0056; 0057; 0063; 0064
(2017/08/28)
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- Distinctive size effects of Pt nanoparticles immobilized on Fe3O4@PPy used as an efficient recyclable catalyst for benzylic alcohol aerobic oxidation and hydrogenation reduction of nitroaromatics
-
Fe3O4@PPy composite microspheres have been synthesized using Fe3O4 microspheres as a chemical template in an ultrasonic treatment process. Pt nanoparticles (NPs) were immobilized on Fe3O4@PPy by using ethylene glycol (EG) and NaBH4 as reducing agents. The information on the morphologies, sizes, and dispersion of Pt NPs of the as-prepared catalysts was verified by TEM, XRD, FTIR and XPS. As expected, the chemical reduction methods remarkably affected the size of Pt NPs (~2.5 nm and ~5.5 nm) and the prepared catalysts exhibited high catalytic activities as well as awesome stabilities for aerobic oxidation of benzylic alcohols and hydrogenation reduction of nitroaromatics. It was highlighted that size effects for the catalytic properties of the two reactions were found to be quite different. Fe3O4@PPy-Pt (2.5 nm) afforded a higher conversion for benzylic alcohol aerobic oxidation, while the selectivities toward benzaldehyde over these two catalysts were similar. However, they showed almost the same catalytic performance for hydrogenation reduction of a majority of nitroaromatics. What is more, Fe3O4@PPy-Pt (5.5 nm) gave better activities than several nitroaromatics, which were relatively difficult to be hydrotreated under the same conditions. In addition, the EG reduced Fe3O4@PPy-Pt catalyst exhibited slightly poorer stability than the NaBH4 reduced Fe3O4@PPy-Pt catalyst in the recycle tests, which might be due to the agglomeration of small Pt NPs.
- Long, Yu,Yuan, Bing,Niu, Jianrui,Tong, Xin,Ma, Jiantai
-
p. 1179 - 1185
(2015/02/19)
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- Facile protocol for reduction of nitroarenes using magnetically recoverable CoM0.2Fe1.8O4 (M = Co, Ni, Cu and Zn) ferrite nanocatalysts
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Transition metal doped cobalt ferrite (CoM0.2Fe1.8O4 (M = Co, Ni, Cu, Zn)) nanoparticles were fabricated using the sol-gel methodology. The obtained ferrite nanoparticles were annealed at 400 °C and characterized using Fourier transform infra-red spectroscopy (FT-IR), X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), vibrating sample magnetometry (VSM) and energy dispersive X-ray (EDX) and scanning transmission electron microscopy (STEM). In the FT-IR spectra two bands in the range 1000-400 cm-1 were observed corresponding to the M-O bond in the tetrahedral and octahedral sites. XRD patterns confirmed the formation of a cubic spinel structure with a Fd3m space-group. HR-TEM analysis revealed a quasi-spherical shape with particle sizes in the range 20-30 nm for all the synthesized ferrite nanoparticles. The lattice inter-planar distances of 0.29, 0.25, 0.21 and 0.16 nm obtained from HR-TEM corresponding to the (2 2 0), (3 1 1), (4 0 0) and (5 1 1) lattice planes respectively were in complete agreement with the XRD data. The EDX-STEM confirmed the elemental composition as per the desired stoichiometric ratio. The catalytic efficiency of the synthesized ferrite samples was explored for the reduction of nitrophenols. Cu substituted cobalt ferrite nanoparticles (CoCu0.2Fe1.8O4) possessed excellent catalytic activity while CoM0.2Fe1.8O4 (M = Co, Ni and Zn) were inactive for the same. The substrate scope of the developed protocol was also evaluated for the reduction of various CH3-, NH2-, Br-, Cl- etc. substituted nitroaromatic compounds.
- Goyal, Ankita,Kapoor, Surbhi,Samuel, Pankaj,Kumar, Vinod,Singhal, Sonal
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p. 51347 - 51363
(2015/06/25)
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- Chemoselective hydrogenation of halonitroaromatics over platinum on carbon as catalyst in supercritical carbon dioxide
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The chemoselective hydrogenation of 2-chloronitrobenzene to 2-chloroaniline over platinum on carbon (Pt/C) as catalyst in supercritical carbon dioxide (scCO2) was investigated. In the scCO2 phase, undesired dehalogenation was significantly suppressed to yield 2-chloroaniline in 99.7% selectively. The utilization of scCO2 resulted in an about two-fold increase in the rate of the reaction compared to the solvent-free conditions. Visual inspection of phase behaviour of the reaction mixture revealed that the formation of a single supercritical phase including substrate, hydrogen, and products, is the crucial factor for the facile hydrogenation of nitro groups. In situ diffuse reflectance FT-IR spectroscopy revealed that carbon monoxide generated in situ by the reverse water-gas shift reaction (CO2+H 2→CO+H2O) poisoned selectively platinum active sites that promoted undesired side reactions including dehalogenation and hydrogenation of aromatic rings, resulting in the excellent product selectivity in scCO2. The untouched active sites efficiently catalyzed the nitro group hydrogenation in scCO2, thereby realizing the highly chemoselective hydrogenation to haloanilines. The present chemoselective hydrogenation is applicable to other chlorinated nitrobenzenes to give the desired products in 100% conversion and with over 99% selectivity.
- Ichikawa, Shinichiro,Seki, Tsunetake,Ikariya, Takao
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supporting information
p. 2643 - 2652
(2014/09/30)
-
- First application of core-shell Ag@Ni magnetic nanocatalyst for transfer hydrogenation reactions of aromatic nitro and carbonyl compounds
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A magnetically separable core-shell Ag@Ni nanocatalyst was prepared by a simple one-pot synthetic route using oleylamine both as solvent and reducing agent and triphenylphosphine as surfactant. The synthesized nanoparticles were characterized by several techniques such as X-ray diffraction pattern (XRD), high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED) pattern, and energy dispersive X-ray spectroscopy (EDS). The core-shell Ag@Ni nanocatalyst was found to have very excellent activity for the transfer hydrogenation reactions of aromatic nitro and carbonyl compounds under mild conditions using isopropyl alcohol as hydrogen donor. Excellent chemoselectivity and regioselectivity for the nitro group reduction was demonstrated. The Royal Society of Chemistry 2013.
- Gawande, Manoj B.,Guo, Huizhang,Rathi, Anuj K.,Branco, Paula S.,Chen, Yuanzhi,Varma, Rajender S.,Peng, Dong-Liang
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p. 1050 - 1054
(2013/03/13)
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- Perovskite-type ferromagnetic BiFeO3 nanopowder: A new magnetically recoverable heterogeneous nanocatalyst for efficient and selective transfer hydrogenation of aromatic nitro compounds into aromatic amines under microwave heating
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Perovskite-type ferromagnetic BiFeO3 nanopowder was readily synthesized via thermal decomposition of Bi[Fe(CN)6].5H2O complex and characterized using thermal analysis (TGA/DSC), X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), magnetic measurement and Brunauer-Emmett- Teller (BET) specific surface area measurements. The magnetic measurements show a ferromagnetic behavior for the BiFeO3 nanoparticles at room temperature. This nanosized ferromagnetic oxide with an average particle size of approximately 20 nm and a specific surface area of 48.5 m2/g was used as a new magnetically recoverable heterogeneous nanocatalyst for the highly efficient and selective reduction of aromatic nitro compounds into their corresponding amines by using propan-2-ol as the hydrogen donor under microwave irradiation. This method is regio- and chemoselective, clean, inexpensive and compatible with the substrates having hydrogenlyzable or reducible functional groups. As compared with conventional heating, this method is very fast and suitable for the large-scale preparation of different substituted anilines as well as other arylamines. The catalyst can also be reused without loss of activity. Iranian Chemical Society 2012.
- Farhadi,Rashidi
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p. 1021 - 1031
(2013/02/23)
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- Regio- and chemoselective reduction of nitroarenes and carbonyl compounds over recyclable magnetic ferrite-nickel nanoparticles (Fe3O 4-Ni) by using glycerol as a hydrogen source
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Reduction by magnetic nano-Fe3O4-Ni: A facile, simple and environmentally friendly hydrogen-transfer reaction that takes place over recyclable ferrite-nickel magnetic nanoparticles (Fe3O 4-Ni) by using glycerol as hydrogen source allows aromatic amines and alcohols to be synthesized from the precursor nitroarenes and carbonyl compounds (see figure). Copyright
- Gawande, Manoj B.,Rathi, Anuj K.,Branco, Paula S.,Nogueira, Isabel D.,Velhinho, Alexandre,Shrikhande, Janhavi J.,Indulkar, Utkarsha U.,Jayaram, Radha V.,Ghumman, C. Amjad A.,Bundaleski, Nenad,Teodoro, Orlando M. N. D.
-
supporting information
p. 12628 - 12632
(2012/11/07)
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- A new class of heterogeneous platinum catalysts for the chemoselective hydrogenation of nitroarenes
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A new series of nanostructured platinum catalysts able to catalyze the selective reduction of nitroarenes has been developed. The materials, made of organosilica physically doped with nanostructured platinum(0), are stable and efficient. Reactions in general proceed with high yield and often go to completion, while the catalysts can be reused in further reaction runs. This establishes a new class of relevant solid catalysts for synthetic organic chemistry named SiliaCat Platinum-Hydrogel.
- Pandarus, Valerica,Ciriminna, Rosaria,Beland, Francois,Pagliaro, Mario
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scheme or table
p. 1306 - 1316
(2011/06/25)
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- Perovskite-type LaFeO3 nanoparticles prepared by thermal decomposition of the La[Fe(CN)6]·5H2O complex: A new reusable catalyst for rapid and efficient reduction of aromatic nitro compounds to arylamines with propan-2-ol under microwave irradiation
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Perovskite-type LaFeO3 nanoparticles were readily synthesized via thermal decomposition of the La[Fe(CN)6]·5H2O complex and characterized by using thermal analysis (TGA), X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and BET specific surface area measurement. This nanosized perovskite-type oxide with an average particle size of 35 nm and a specific surface area 38.5 m2/g was used as a new reusable heterogeneous catalyst for highly efficient and selective reduction of aromatic nitro compounds into their corresponding amines by using propan-2-ol as the hydrogen donor under microwave irradiation. This method is regio- and chemoselective, clean, inexpensive and compatible with the substrates having hydrogenlysable or reducible functional groups. As compared with conventional heating, this method is very fast and suitable for large scale preparation of different substituted anilines as well as other arylamines. The catalyst can also be reused without observable loss of its activity.
- Farhadi, Saeid,Siadatnasab, Firouzeh
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experimental part
p. 108 - 116
(2011/05/19)
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- Microwave-assisted rapid and efficient reduction of aromatic nitro compounds to amines with propan-2-ol over Nanosized perovskite-type SmFeO 3 powder as a new recyclable heterogeneous catalyst
-
Nanosized perovskite-type SmFeO3 powder, prepared through the thermal decomposition of Sm[Fe(CN)6].4H2O with an average particle diameter of 28 nm and a specific surface area of 42 m2 g-1, was used as a recyclable heterogeneous catalyst for the efficient and selective reduction of aromatic nitro compounds into the corresponding amines by using propan-2-ol as a hydrogen donor (reducing agent) and KOH as a promoter under microwave irradiation. This highly regio-and chemoselective catalytic method is fast, clean, inexpensive, high yielding and also compatible with the substrates containing easily reducible functional groups. In addition, the nanosized SmFeO3 catalyst can be reused without loss of activity.
- Farhadi, Saeid,Siadatnasab, Firouzeh,Kazem, Maryam
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experimental part
p. 104 - 108
(2011/06/27)
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- NiO nanoparticles prepared via thermal decomposition of the bis(dimethylglyoximato)nickel(II) complex: A novel reusable heterogeneous catalyst for fast and efficient microwave-assisted reduction of nitroarenes with ethanol
-
NiO nanoparticles with an average size of 12 nm and a high specific surface area of 88.5 m2/g were easily prepared via the thermal decomposition of the complex Ni(dmgH)2 and were characterized by TGA, XRD, FT-IR, TEM and BET surface area measurement. This nanosized transition metal oxide was used as a new heterogeneous catalyst for the reduction of nitroarenes under microwave irradiation. The efficient and selective reduction of aromatic nitro compounds into their corresponding amines was observed by using ethanol as a hydrogen donor (reducing agent) and KOH as a promoter under microwave irradiation. This highly regio-and chemoselective method is fast, simple, inexpensive, high yielding, clean and compatible with several sensitive functionalities, such as halogens,-OH,-OCH3,-CHO,-COCH 3,-COOH,-COOEt,-CONH2,-CN,-CHCH2 and-NHCOCH3. This method is suitable for the large scale preparation of different substituted anilines as well as other arylamines. In addition, the catalytic activity of nanosized NiO is higher than that of the bulk sample.
- Farhadi, Saeid,Kazem, Maryam,Siadatnasab, Firouzeh
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scheme or table
p. 606 - 613
(2011/04/16)
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- PRODRUG AND FLUOREGENIC COMPOSITIONS AND METHODS FOR USING THE SAME
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Methods and compositions for treating disease caused by increased iron levels are disclosed Fluoregenic compounds and methods of using the same are also described.
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Page/Page column 63
(2010/04/03)
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- An efficient method for aryl nitro reduction and cleavage of azo compounds using iron powder/calcium chloride
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A novel, efficient Fe/CaCl2 system is revealed for the reduction of nitroarenes and reductive cleavage of azo compounds by catalytic transfer hydrogenation (CTH). The selective reduction of nitro compounds in the presence of sensitive functional groups including halides, carbonyl, hydroxyl, aldehyde, methyl, methoxy, acetyl, nitrile, and ester substituents with an excellent yields is reported. The simple experimental procedure and easy purification make the protocol advantageous
- Chandrappa,Vinaya,Ramakrishnappa,Rangappa
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experimental part
p. 3019 - 3022
(2011/03/17)
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- Highly selective hydrogenation of aromatic chloronitro compounds to aromatic chloroamines with ionic-liquid-like copolymer stabilized platinum nanocatalysts in ionic liquids
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Platinum nanoparticles (PtNPs stabilized by an ionic-liquid-like-copolymer (IP) immobilized in various ionic liquids (ILs)) effectively catalyze the selective hydrogenation of aromatic chloronitro compounds to aromatic chloroamines, a reaction of considerable commercial significance. The preparation of 2,4-dichloro-3-aminophenol (DAP) has been primarily studied due to its important industrial applications. DAP is usually prepared from 2,4-dichloro-3-nitrophenol (DNP) by reduction with hydrogen using Ni- or Pt-based catalysts. Compared to reactions in molecular (organic) solvents, the ILs system provides superior selectivity with functionalized ILs containing an alcohol group demonstrating the best recyclability, and ultimately achieving a turnover number of 2025 which is 750 fold higher than Raney nickel catalyst. A universal catalyst-ionic liquid system for the conversion of aromatic chloronitro compounds to aromatic chloroamines was also established. TEM, XPS, IR spectroscopy were used to characterize the morphology of the nanocatalysts allowing their structure to be correlated to their activity.
- Yuan, Xiao,Yan, Ning,Xiao, Chaoxian,Li, Changning,Fei, Zhaofu,Cai, Zhipeng,Kou, Yuan,Dyson, Paul J.
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experimental part
p. 228 - 233
(2011/03/17)
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- Easy copper-catalyzed synthesis of primary aromatic amines by coupling aromatic boronic acids with aqueous ammonia at room temperature
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(Chemical Equation Presented) A reaction without the added extras: Aromatic boronic acids have been coupled using inexpensive aqueous ammonia to give primary aromatic amines under copper catalysis. This simple and highly efficient approach can be carried
- Rao, Honghua,Fu, Hua,Jiang, Yuyang,Zhao, Yufen
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supporting information; experimental part
p. 1114 - 1116
(2009/06/20)
-
- Discovery of pyrano[3,4-b]indoles as potent and selective HCV NS5B polymerase inhibitors
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A novel series of HCV NS5B RNA-dependent RNA polymerase inhibitors containing a pyrano-[3,4-b]indole scaffold is described leading to the discovery of compound 16, a highly potent and selective inhibitor that is active in the replicon system.
- Gopalsamy, Ariamala,Lim, Kitae,Ciszewski, Gregory,Park, Kaapjoo,Ellingboe, John W.,Bloom, Jonathan,Insaf, Shabana,Upeslacis, Janis,Mansour, Tarek S.,Krishnamurthy, Girija,Damarla, Murthy,Pyatski, Yelena,Ho, Douglas,Howe, Anita Y. M.,Orlowski, Mark,Feld, Boris,O'Connell, John
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p. 6603 - 6608
(2007/10/03)
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- Electrochemical synthesis of 2,5-dichloroaniline
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A procedure was proposed for electrochemical reduction of 2,5-dichloronitrobenzene to 2,5-dichloroaniline in aqueous-ethanolic solution of sulfuric acid. The procedure for preparing 2,5-dichloroanilinium sulfate was optimized. The influence exerted by the cathode material, nature and amount of the organic solvent, sulfuric acid concentration, and electrolysis temperature on the yield and quality of the target product was discussed.
- Islamgulova,Tomilov,Akhmerova,Gil'mkhanova,Sapozhnikov
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p. 1076 - 1078
(2007/10/03)
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- Novel ZnX2-modulated Pd/C and Pt/C catalysts for chemoselective hydrogenation and hydrogenolysis of halogen-substituted nitroarenes, alkenes, benzyl ethers, and aromatic ketones
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Novel ZnX2-modulated Pd/C and Pt/C catalysts were developed to chemoselectively hydrogenate halogen-substituted nitroarenes, alkenes, benzyl ethers, and aromatic ketones.
- Wu, George,Huang, Mingsheng,Richards, Monique,Poirier, Marc,Wen, Xin,Draper, Richard W.
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p. 1657 - 1660
(2007/10/03)
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- Pharmacologically active pyridine derivatives and processes for the preparation thereof
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N-phenyl-2-pyrimidineamine derivatives of formula I STR1 wherein the substituents are as defined in claim 1 and the derivatives of formula I can be used, for example, in the treatment of tumour diseases.
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- Pigment compositions for solvent and water-based ink systems and the methods for producing them
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This invention is an azo pigment composition containing a water insoluble metal salt of a water soluble polymer; a method of preparing said composition and ink compositions prepared from said azo pigment compositions.
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-
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- Azo pigment compositions and process for their preparation
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This invention is that of an azo pigment composition containing about 1 to 10 percent by weight of a nonionic alkyl polyglycoside dispersing agent. The polyglycosides useful in the invention have the general formulae: wherein: M is an oxygen, sulfur, nitrogen phosphorous or silicon atom; n is an integer from 8 to 18, preferably 8 to 11 and X represents the number average degree of polymerization having a numerical value from about 1 to about 2. These azo pigment compositions are prepared by conducting the azo pigment coupling reaction in the presence of said alkyl polyglycoside. The resulting pigment exhibit superior application properties in water based ink systems.
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-
-
- Magnetic susceptibilities of organic compounds: Part V - Influence of substituents on diamagnetic susceptibilities of disubstituted and trisubstituted benzenes
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The magnetic susceptibilities of a number of triads of isomeric disubstituted benzenes have been determined, choosing the compounds in such a way that the substituents are present in the following combinations: (i) two electron-releasing substituents, (ii) a halogeno and an electron-releasing substituent, (iii) a halogeno and an electron-attracting substituent, and (iv) two halogeno substituents.The data show that for types (i), (ii) and (iv), the ortho isomers have the highest magnetic susceptibilities, the susceptibilities decreasing in the order: ortho > meta > para; for type (iii), the meta-isomers have the highest susceptibilities, the susceptibilities decreasing in the order: meta > para > ortho.The diamagnetic susceptibilities of some isomeric trisubstituted benzenes have also been determined and the data reveal that the susceptibility is the highest where the crowding of substituents is the highest (1,2,3-isomer) and lowest where the substituents are staggered and least crowded (1,3,5-isomer).Another observation made in the case of trisubstituted benzene is the applicability of a principle of additivity of their diamagnetic susceptibilities.
- Baliah, V.,Jeyanthy, J. Judith Diana
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p. 472 - 476
(2007/10/02)
-
- Catalysts for alkoxylation reactions
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Catalysts producing a sharply peaked alkoxylation distribution during the alkoxylation of organic materials comprise mixtures of BF3 and metal alkyls or metal alkoxides, SiF4 and metal alkyls or metal alkoxides, or mixtures of these catalysts.
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-
-
- Methods of alkoxylation
-
Catalysts comprising mixtures of HF and metal alkoxides and mixed metal alkoxides produce a sharply peaked alkoxylation distribution during the alkoxylation of organic materials.
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-
- Catalysts for alkoxylation reactions
-
Catalysts and a method of using said catalysts for the alkoxylation of a variety of materials is disclosed. Catalysts so described produce alkoxylates having a very sharp alkoxylate distribution. The catalysts are supported and unsupported dialkoxy and dialkyl metal fluorides and halides and alkyl metal difluorides and dihalides.
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-
- The Reactions of Superoxide Ion with Arylhydrazines
-
Arylhydrazines react with potassium superoxide to give a variety of products, most of which are derived from interaction of aryl radicals with the solvent.Phenylhydrazine in toluene gives three isomeric metylbiphenyls, diphenylmethane and bibenzyl.In pyridine, the products identified were 2-, 3-, and 4-phenylpyridine.A more complex range of products was obtained from substituted phenylhydrazines.Products are consistent with a process in which superoxide ion abstracts hydrogen atoms from the hydrazines giving radical intermediates, including aryl radicals, which react with the solvents.
- Crank, George,Gately, Garry E.,Makin, Mohammad I. H.
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p. 2499 - 2507
(2007/10/02)
-
- Hydrogenation of halogen-substituted aromatic nitro compounds
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This invention relates to the hydrogenation of halogen-substituted aromatic nitro compounds and in particular provides a novel catalyst for use in such processes. In more detail a catalyst suitable for use in the hydrogenation of halogen-substituted aromatic nitro compounds substantially without simultaneous dehalogenation comprises one or more metals from the group consisting of platinum, palladium, rhodium, iridium, ruthenium and osmium supported on or impregnated into a carrier material comprising carbon activated with phosphoric acid or a salt thereof.
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- Novel Reactions: Part I - Facile Synthesis of Substituted ortho-Chloranilines from Nitrobenzene Derivatives
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N-Substituted benzo and acetohydroxamic acids (5), prepared from N-arylhydroxylamines and benzoyl or acetyl chloride, react readily with thionyl chloride at low temperature to give ortho-chloroanilide derivatives (6) in good yield.The latter (6) on hydrolysis give ortho-chloroanilines (10).Since the N-arylhydroxylamines are obtained from nitroarenes by partial reduction, the overall reaction amounts to the preparation of 10 from nitroarenes.
- Ayyangar, N. R.,Kalkote, U. R.,Nikrad, P. V.
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p. 872 - 877
(2007/10/02)
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- A High Current Density Electrosynthesis of Amines from Nitro Compounds Using Metal Powders as Intermediates
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Copper, iron, tin and zinc powders may each be formed in very good yield in acidic aqueous solution by electrolysis at high current density (0.5 A cm-2) of a solution of their metal salts (0.4 - 1.0 M) in an appropriate electrolyte.It is further shown that a range of nitro compounds may be reduced to the corresponding amines by electrolysis at 0.5 A cm-2 of an emulsion of the nitro compound, or its solution in an inert solvent, with the aqueous medium for deposition of the metal powder (typical ratio of water to organic 4:1).Tin and zinc are the best metals for this reaction when the organic and currenr yields can exceed 90percent.
- Gunawardena, Neelakanthie Ekanayake,Pletcher, Derek
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p. 549 - 554
(2007/10/02)
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- Process for the preparation of chlorine-substituted aromatic amines
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An improved process for the preparation of a chlorinated aromatic amine by reaction of a chlorinated aromatic nitro compound of the formula STR1 wherein R1 and R2 are identical or different and denote hydrogen or chlorine with hydrogen in the presence of a hydrogenation catalyst under pressure at an elevated temperature in the presence of a solvent and a minor amount of a basic compound, the improvement residing in employing ammonia as the basic compound.
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- Water-soluble trisazo 8-amino-naphthol-1 dyes
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Very effective direct dyeing of cotton and other hydroxyl- or nitrogen-containing fibers is effected with water-soluble triasazo dyes having the formula: where A is a radical of a diazoconstituent and A3 is a radical of a coupling constituent STR1 and A1 or A2 or both can have their azo linkages reversed. These dyes are very fast particularly to washing and to perspiration, and are so effective with cotton that dye baths for such use are rapidly exhausted and the disposal of used bath is less of a problem.
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- Process for the preparation of O-aminothiophenols
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Preparation and isolation in substance of ortho-aminothiphenols by the reduction of ortho-chloronitrobenzenes with hydrogensulfides or sulfides, subsequent neutralization in the presence of sulfites, hydrogensulfites or disulfites, separation and following purification of the crude products. The ortho-aminothiophenols are obtained in very good yields and with a high degree of purity. Oxydation to the disulfide compound is avoided by the processes of the invention.
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- Azo pigments derived from 2-hydroxy-3-carboxynaphthalene containing a substituted or unsubstituted phthalimide
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Azo pigments derived from 2-hydroxy-3-carboxy-naphthalene and containing a substituted or unsubstituted phthalimide radical. The majority give red colorations and due to their excellent fastness properties are particularly valuable for use in surface coatings and resins.
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