- Synthesis method of 4-nitrosodiphenylamine
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The invention relates to a synthesis method of p-nitrosodiphenylamine, in particular to a new process for preparing p-nitrosodiphenylamine by reacting N-carbanilide with nitrobenzene in the presence of proper alkali and a solvent. According to the invention, N-carbanilide with excellent reactivity and selectivity is adopted to react with nitrobenzene, and cheap alkali metal, alkaline earth metal and a polar organic solvent are adopted. And the method has the advantages of simple process, no by-product, high yield, no corrosive wastewater and environmental pollution reduction. And no chlorine-containing wastewater is generated, so that factors for corroding equipment can be eliminated.
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Paragraph 0009; 0010
(2021/04/26)
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- Preparation method of 4-nitrodiphenylamine and 4-nitrosodiphenylamine
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The invention provides a preparation method of 4-nitrodiphenylamine and 4-nitrosodiphenylamine. The preparation method comprises the following steps: (1) dissolving anhydride and/or aromatic dibasic acid as well as aniline into an organic solvent and performing ammonolysis or acylation reaction; and (2) adding nitrobenzene and a catalyst into the solution obtained in the step (1) and performing condensation reaction to generate the 4-nitrodiphenylamine and the 4-nitrosodiphenylamine. A reaction product of the aniline and the anhydride and/or the aromatic dibasic acid is used for replacing theaniline to react with the nitrobenzene, so on one hand, the steric hindrance of the reaction product and nitrobenzene ortho-reaction is increased and generation of ortho-reaction byproducts is effectively inhibited; and on the other hand, the protective effect on amino is achieved and the side reaction that two molecule aniline are condense to generate azobenzene is avoided, so that the yield of the target product is increased and energy consumption in the separation and purification link is reduced. Furthermore, the cost of the raw materials such as the anhydride and the aromatic dibasic acidis low, and the method is suitable for industrialized production.
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Paragraph 0049-0090
(2019/02/04)
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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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p. 555 - 557
(2016/11/29)
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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
(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
(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 19; 20
(2013/09/26)
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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 28-29
(2013/11/05)
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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 8-9
(2008/06/13)
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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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- 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 9-10
(2008/06/13)
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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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- Process for preparing 4-aminodiphenylamine intermediates
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The invention is directed to a method of producing one or more 4-aminodiphenylamine intermediates comprising the steps: a. bringing an aniline or aniline derivative and nitrobenzene into reactive contact; and b. reacting the aniline and nitrobenzene in a confined zone at a suitable time and temperature, in the presence of a mixture comprising a strong organic base, or equivalent thereof, and an oxidant comprising hydrogen peroxide in an amount of from about 0.01 to about 0.60 moles of hydrogen peroxide to moles of nitrobenzene.
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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 12-13
(2008/06/13)
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- Process for producing 4-Nitrosodiphenylamines or their salts
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Disclosed is a process for producing a 4-nitrosodiphenylamine of the formula (2) STR1 wherein R1 and R2 independently represent hydrogen atom, methyl group, ethyl group, cyclohexyl group, methoxy group, ethoxy group or chlorine or bromine atom, or a salt thereof, comprising treating a diphenylamine represented by the formula (1) STR2 wherein R1 and R2 are as defined above with (i) a mixture of nitrogen oxides, (ii) a hydrogen halide and (iii) an aliphatic alcohol, wherein the atomic ratio of oxygen to nitrogen of the mixture of nitrogen oxides is more than 1.0 and less than 2.0. This process produces 4-nitrosodiphenylamine of the formula (2) or a salt thereof conveniently and effectively, and is industrially advantageous.
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- Method of preparing 4-aminodiphenylamine
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A method of producing 4-ADPA is disclosed wherein aniline or substituted aniline derivatives and nitrobenzene are reacted under suitable conditions to produce 4-nitrodiphenylamine or substituted derivatives thereof and/or 4-nitrosodiphenylamine or substituted derivatives thereof and/or their salts, either or both of which are subsequently reduced to produce 4-ADPA or substituted derivatives thereof. The 4-ADPA or substituted derivatives thereof can be reductively alkylated to produce p-phenylenediamine products or substituted derivatives thereof which are useful as antiozonants. A second embodiment of the invention is the tetrasubstituted ammonium salts or alkyl substituted diammonium salts of 4-nitrodiphenylamine, 4-nitrosodiphenylamine and the substituted derivatives thereof wherein each substituent of the tetrasubstituted ammonium ion is independently selected from the group consisting of alkyl, aryl and arylalkyl groups and each alkyl substituent of the alkyl substituted diammonium salt is independently selected.
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- Method of preparing 4-aminodiphenylamine
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A method of producing 4-ADPA is disclosed wherein aniline and nitrobenzene are reacted under suitable conditions to produce 4-nitrodiphenylamine and/or 4-nitrosodiphenylamine and/or their salts, either or both of which are subsequently reduced to produce 4-ADPA. The 4-ADPA can be reductively alkylated to produce p-phenylenediamine products which are useful as antiozonants.
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- A NOVEL REACTION OF ACETANILIDE WITH NITROBENZENE IN DMSO - AN UNUSUAL SOLVENT ASSISTED REGIOSELECTIVE AROMATIC NUCLEOPHILIC SUBSTITUTION
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The reaction of acetanilide (1) with nitrobenzene (2) in the presence of a base in DMSO yielded p-nitrosodiphenylamine (3) as the major product.This unusual regioselective formation of the deoxygenated product 3 has been rationalized in terms of solvent effects exerted by DMSO.
- Ayyangar, N. R.,Naik, S. N.,Srinivasan, K. V.
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p. 3217 - 3220
(2007/10/02)
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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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p. 694 - 696
(2007/10/02)
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- Process for the preparation of p-nitrosodiphenylamine
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A process is disclosed for the preparation of p-nitrosodiphenylamine hydrochloride comprising reacting diphenylamine, C5 -C10 alkyl nitrite and anhydrous HCl in the presence of a C5 -C10 aliphatic alcohol and essentially in the absence of an aromatic solvent.
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- Preparation of p-nitrosodiphenylamine
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A process for preparing p-nitrosodiphenylamine hydrochloride is provided from N-nitrosodiphenylamine and hydrogen chloride. The product is prepared in the absence of an aromatic solvent and using a solvent consisting essentially of aliphatic C5 -C10 alcohol.
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- Preparation of p-aminodiphenylamines
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A method of preparing p-aminodiphenylamines from diphenylamines is described whereby neither the N-nitrosodiphenylamine or the p-nitrosodiphenylamine need be isolated. The method rests on the discovery that alkali metal salts of p-nitrosodiphenylamines are soluble in non-aqueous organic solvent systems consisting of certain aromatic hydrocarbons and saturated aliphatic alcohols, and that such salts can be readily hydrogenated in their non-aqueous solution to the corresponding p-aminodiphenylamine.
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- Process for the preparation of 4-nitroso-diphenyl-amine
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A process for the preparation of 4-nitroso-diphenylamine by rearranging N-nitroso-diphenylamine according to Fischer-Hepp to o-dichlorobenzene, under the effect of alcoholic hydrochloric acid and working up the suspension of the 4-nitroso-diphenylamine-hydrochloride.
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- Method for producing 4-nitrosodiphenylamine
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A method for producing 4-nitrosodiphenylamine, consisting in diphenylamine nitrozation with nitrites of alkali metals or ammonium nitrite in the presence of an acid and an organic solvent nonmiscible with water; said nitrozation being carried out under stirring with a speed determined by Reynolds number not below, 8-10×103 or in the presence of polymers of methacrylic acid esters in an amount of 0.01-0.02% of the reaction mixture weight under stirring with a speed determined by Reynolds number equal to 4-5×103 ; this is followed by rearrangement of the resultant N-nitrosodiphenylamine with anhydrous hydrogen chloride in an inert gas atmosphere in the presence of an alkyl 4-aminodiphenylamine in an amount of 0.5-1% of the N-nitrosodiphenylamine weight, with subsequent neutralization of the formed 4-nitrosodiphenylamine hydrochloride and isolation of the desired product. The method described above makes it possible to increase the product yield at the nitrozation stage by a factor of 5-6 and to raise the yield of the desired product up to 99% in terms of the converted N-nitrosodiphenylamine. 4-Nitrosodiphenylamine produced serves as an intermediate in the synthesis of antioxidants for rubbers and plastics, in the synthesis of dyestuffs, and is also used as a component in a number of antioxidant compositions.
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- Process for the production of 4-nitroso-diphenylamine
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Object of the invention is a process for the production of 4-nitroso diphenylamine wherein N-nitroso diphenylamine is rearranged in the presence of an alcoholic hydrogen chloride solution by selecting the reaction conditions in such a way that the hydrochloride of 4-nitroso diphenylamine remains dissolved in the reaction medium. In this way spontaneous, uncontrollable decompositions do not occur.
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