- Synthesis of 2-methyl-4-methoxydiphenylamine by palladium catalyzed C-N coupling - High synthetic versatility by use of a flexible catalytic system
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The synthetic versatility of the Buchwald-Hartwig Amination is demonstrated by the synthesis of the industrially important intermediate 2-methyl-4-methoxydiphenylamine. Using four routes differing in the choice of the starting materials, the diarylamine could be synthesized in excellent yields, however, each reaction required a different combination of ligand, base and solvent. This new approach is compared to established industrial routes.
- Scholz, Ulrich,Schlummer, Bj?rn
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- A terphenyl phosphine as a highly efficient ligand for palladium-catalysed amination of aryl halides with 1° anilines
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A terphenyl phosphine ligand (2,6-bis(2,4,6-triisopropylphenyl)phenyl-dicyclohexylphosphine, TXPhos) and its supported palladium complex [(TXPhos)(allyl)PdCl] have been developed and the catalyst system is highly efficient in amination of aryl halides with 1° anilines, especially effective for densely functionalized substrates including both partners possessing ortho-ester, acetyl, nitrile and nitro groups. With the TXPhos-supported catalyst system, many partner combinations have been unprecedentedly realized and the base scope has been even extended to KOAc, which is even the best choice in the amination of 2-nitrochlorobenzene.
- Shi, Ji-cheng,Zhang, Lixue,Zhou, Fabin
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p. 238 - 243
(2021/09/07)
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- Preparation method and application of 2-methyl-4-methoxydiphenylamine
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The invention relates to the field of preparation of diphenylamine, in particular to a preparation method and application of 2-methyl-4-methoxydiphenylamine, and the preparation method of the 2-methyl-4-methoxydiphenylamine comprises the following steps: (1) in a solvent, reacting 2-methyl-4-methoxyaniline with halogenated benzoic acid in the presence of a catalyst and an acid-binding agent to obtain a condensation product, wherein the acid-binding agent is selected from one or more of carbonate, phosphate and hydroxide of alkali metal; (2) acidifying the condensation product, and conducting filtering, washing and drying to obtain a product 1; and (3) decarboxylating the product 1, and conducting purifying to obtain the product 1. The preparation method of the 2-methyl-4-methoxydiphenylamine is convenient to operate, short in time and suitable for large-scale production, and the production efficiency is greatly improved.
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Paragraph 0070-0098
(2021/06/23)
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- Preparation method of secondary aromatic amine
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The invention provides a method for preparing secondary aromatic amine by performing a palladium-catalyzed C-N coupling reaction on (pseudo)aryl halide and (pseudo)heterocyclic aryl halide and primary(heterocyclic)aromatic amine. The method is characterized in that an alkali for promoting the reaction is an alkali metal carboxylate or an alkali metal bicarbonate.
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Paragraph 0024
(2021/03/31)
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- Synthesis method of DPA
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The invention discloses a synthesis method of DPA. The method comprises the following steps: (1) adding methanol, o-nitrotoluene, a catalyst, concentrated sulfuric acid, distilled water into an autoclave, performing heating with stirring to 50 DEG C, evacuating air and then introducing hydrogen, controlling a pressure in the autoclave to 0.1 MPa, carrying out a reaction for 5 h, then performing suction filtration, distilling a filtrate to remove methanol, diluting a residual solution by adding water and then adjusting pH to be neutral with ammonia water, performing extracting with toluene, washing an organic phase with a dilute sodium hydroxide solution, and performing reduced pressure distillation on the organic phase to obtain 4-methoxy-2-methylaniline; and (2) adding 4-methoxy-2-methylaniline, phenol naphthalene, cyclohexanone, and the catalyst into an autoclave, replacing air with nitrogen, performing heating to 250 DEG C, controlling a pressure in the autoclave to 1 Mpa, performing cooling to room temperature after a reaction is completed, filtering a reaction solution, and performing reduced pressure distillation on a filtrate and collecting various fractions, wherein a latter fraction is DPA. The raw materials are cheap and easy to obtain, the operation is simple, the yield is high, the energy consumption is low, and the method has practical value and economic value, andis suitable for enterprise production.
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Paragraph 0007
(2020/01/25)
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- Synthetic method of -4- 2- methyl-methoxyl diphenylamine (by machine translation)
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After the reaction is finished, the 2 - organic phase is extracted with DMF toluene, concentrated, vacuum-dried (1) to obtain the intermediate product, (2) and the obtained intermediate product is evaporated and decarboxylated in a methanol system 10~20min 2 - 6~10h 2 . To the synthesis method, the reaction conversion efficiency and selectivity are improved, the raw material conversion rate is improved, the produced process wastewater is less, and the production cost is low. (by machine translation)
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Paragraph 0022-0035
(2019/11/29)
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- Ligand recyclable type method for synthesizing 2-methyl-4-methoxydiphenylamine by catalyzing through copper
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The invention provides a ligand recyclable type method for synthesizing 2-methyl-4-methoxydiphenylamine by catalyzing through copper. The method takes 2-methyl-4-methoxyaniline and bromobenzene as rawmaterials, an alcohol type compound as a solvent, the copper or a compound of the copper as a catalyst and PSL with a structural formula shown as a formula (I) as a ligand, and the components are subjected to C-N coupling reaction under an alkaline condition at 25 to 120 DEG C, so as to generate the 2-methyl-4-methoxydiphenylamine. The method for synthesizing the 2-methyl-4-methoxydiphenylamine,provided by the invention, has the advantages that reaction conditions are moderate; the green solvent is utilized and is small in environmental pollution; the yield is high, a product is simple to separate and purify and the PSL is easy to recycle; the activity is basically not changed after the ligand is repeatedly used for a plurality of times. The formula (I) is shown in the description.
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Paragraph 0028; 0108-0109
(2018/07/30)
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- An Effective Heterogeneous Copper Catalyst System for C-N Coupling and Its Application in the Preparation of 2-Methyl-4-methoxydiphenylamine (MMDPA)
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A ligand-recyclable, environmentally benign heterogeneous catalyst system composed of CuI and polystyrene-supported N (-(4-(aminomethyl)naphthalen-1-yl)- N (-phenyl-1 H -pyrrole-2-carbohydrazide (PSAP) has been established for Ullmann type C-N coupling based on the homogeneous catalyst system N ′, N ′-diphenyl-1 H -pyrrole-2-carbohydrazide/CuI. This heterogeneous catalyst system maintained the catalytic effectiveness of the homogeneous catalyst. A variety of functionalized aryl bromides can be efficiently aminated with aryl amines and aliphatic amines with high selectivity for amines over alcohols. Moreover, a practical application of this catalyst system to promote the reaction of commercially available 4-methoxy-2-methylaniline and bromobenzene in 10 mmol scale, provided 2-methyl-4-methoxydiphenylamine (MMDPA) with 93% yield with the merit of the approach being simple operation for work-up and purification.
- Yi, Zhou,Huang, Manna,Wan, Yiqian,Zhu, Xinhai
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p. 3911 - 3920
(2018/09/29)
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- Preparation method of diphenylamine
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The invention relates to a preparation method of diphenylamine, and concretely relates to a preparation method of 2-methyl-4-methoxydiphenylamine. The method comprises the following steps: reacting an initial reaction substance 2-methyl-4-methoxyaniline with halogenated benzoic acid to obtain a carboxyl group-containing diphenylamine compound, and carrying out acidification, decarboxylation and purification to obtain the 2-methyl-4-methoxydiphenylamine.
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Paragraph 0034; 0037; 0040-0042
(2017/10/12)
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- A diphenylamine or nucleus method for preparing substituted derivatives
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The invention discloses a preparation method of a diphenylamine or a nucleus-substituted derivative thereof. The method comprises the following steps: in an aprotic polar solvent, performing reaction on an N-acylation aniline or a nucleus-substituted derivative thereof and alkali to form corresponding salts; performing reaction on the salts and a halogeno benzene or a nucleus-substituted derivative thereof to prepare the N-acylation aniline or a nucleus-substituted derivative thereof; and then, preparing the diphenylamine or a nucleus-substituted derivative thereof through de-acylation reaction in the presence of sodium alkoxide. The method has the beneficial effects that three-step reaction of salifying, condensation and de-acylation in one kettle is sequentially carried out, and a separation and purification process of an intermediate product is eliminated, so that the method is short in processes, short in production cycle and high in yield of products.
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Paragraph 0102-0104; 0108-0116; 0129-0131
(2020/05/05)
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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 0176-0179
(2016/10/08)
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- Process for manufacturing diphenylamines
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The invention teaches novel process steps for the rapid high yield manufacture of diphenylamines of the formula wherein R1 is selected from hydrogen, alkyl, and aryl; wherein each R2 and R3 is the same or different and each is independently selected from hydrogen, alkyl, alkoxy, aralkyl, dialkylamino, alkylarylamino and substituted or unsubstituted aryl, the substituents on aryl being each independently selected from alkyl (C1-C8), alkoxy (C1-C8), aroxy, aralkoxy and halogen; wherein n and m are each independently an integer from 1 to 5. Diphenylamines are key intermediates for the production of leuco dyes used in pressure-sensitive and heat-sensitive imaging systems. The process in at least one embodiment comprises reacting at elevated temperature an aryl halide with an aromatic amine in an organic solvent and aqueous alkaline solution and optionally in some embodiments, phase-transfer agent, followed by addition of catalytic amounts of bis[tri(t-butylphosphine)]palladium at a suitable temperature to rapidly form diphenylamine.
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Page/Page column 7
(2008/06/13)
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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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- Process for preparing diphenylamines
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A process is described for preparing diphenylamines of the formula STR1 by oxybromination of a phenol ether compound using elemental bromine in the presence of hydrogen peroxide and of a catalyst to give a brominated phenol ether compound which is subsequently reacted with a formanilide compound to give the compound of the formula (1). The oxybromination reaction is a regioselective, environmentally friendly and cost-efffective method of preparing brominated aromatic compounds. The diphenylamines of the formula (1) are industrially useful intermediates for the production, for example of dyes, and in particular of color formers of the fluoran type for pressure- or heat-sensitive recording systems.
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- Process for producing diphenylamines or N,N'-diphenyl-phenylenediamines
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Diphenylamines or N,N'-diphenyl-phenylenediamines can be obtained by heat-reacting an aniline or a phenylenediamine with preferably an excess of a phenol in an amount of 4 to 20 moles per mole of the aniline or phenylenediamine in the presence of a hydrogen transfer catalyst and a cyclohexanone corresponding to said phenol. The excess phenol used in the reaction undergoes reduction in the reaction system to form a cyclohexanone, which in turn reacts with the aniline or phenylenediamine to form a Schiff base and is thus consumed. The Schiff base forms the intended product by means of a dehydrogenation reaction, and the hydrogen evolved at this time reduces the phenol to form a cyclohexanone. The phenol present in excess thus becomes in the system a solvent, a starting material for the cyclohexanone, and an acceptor of the hydrogen that forms as a by-product at the time of formation of the intended product. Hence, it becomes possible to obtain the intended product at a high selectivity from the anilines and phenylenediamines. The process of this invention is an advantageous process for the industrial production of especially the nuclearly substituted diphenylamines.
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- Recording material
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The present invention discloses novel fluoran compound useful as the lactone electron donative color-forming agents having the general formula: STR1 wherein, R1, R2 and R4 are respectively hydrogen, methyl or ethyl groups; R3 is hydrogen or a methyl group; and R5 is a phenyl group or a phenyl group substituted with from one to five methyl groups. The compound of the invention is soluble in aromatic solvents as well as in aromatic-aliphatic mixed solvents and also has excellent light fastness after developing color.
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