- Method for preparing biphenyldianhydride isomer by ultrasonic-assisted catalytic coupling
-
The invention discloses a method for preparing biphenyldianhydride isomers through ultrasonic-assisted catalytic coupling. The main contents include a mixture of a nickel salt catalyst and zinc as a reducing agent, 2-THF used as a solvent, an aryl (or methyl) N - chloronaphthalimide and -4 - propyl (or isopropyl) N - chlorodifluoroimide, under -3 - by means of an ultrasonic-assisted catalytic coupling reaction 60 - 100 °C 0.5 - 3 hours. The separation and purification of the three biphenyltetracarboxylic acid isomers are realized by using different solubility parameters, and the biphenyldianhydride isomer pure product is finally obtained. The invention is characterized in that a simple method for separating the three biphenyltetracarboxylic acid isomers is established, the problem of difficulty in separation of the three biphenyl dianhydride mixtures is solved, and 3,4 - biphenyl dianhydride ’ with an asymmetric structure is obtained at lower cost.
- -
-
-
- Method for preparing biphenyldianhydride through microwave-assisted catalytic coupling
-
The invention discloses a method for preparing biphenyldianhydride through microwave-assisted catalytic coupling. In a green solvent 2 - methyltetrahydrofuran (2-THF) system, under microwave irradiation, under microwave irradiation, under a temperature 60 - 95 °C condition, the reaction time is over 20-60 minutes to prepare a biphenyl derivative, and after hydrolysis and dehydration, biphenyldianhydride is obtained. The present invention is characterized in that an organometallic complex is formed by using a halogenated monomer having a complexing action, and zinc halide generated by the reaction with the reaction. It is avoided that its deposition on the reducing agent metal surface results in a reduction in its reducing ability. Compared with the traditional method for preparing the same biphenyl dianhydride, the method is high in reaction speed, the reducing agent is close to the quantitative reaction, and the cost is lower.
- -
-
-
- Method for preparing biphenyl dianhydride by coupling halogenated phthalimide monomer based on metal coordination
-
The invention discloses a method for preparing biphenyl dianhydride by coupling halogenated phthalimide monomers based on metal coordination. The method mainly comprises the following steps: by taking halogenated phthalimide with complexing coordination capacity as a raw material, zinc or magnesium as a reducing agent and nickel salt as a catalyst, carrying out coupling reaction in an aprotic solvent system to generate a biphenyl derivative, and hydrolyzing and dehydrating to obtain anhydride. A halogenated monomer with a coordination effect and a by-product zinc halide generated by a reaction form an organic metal complex, and the organic metal complex is dissolved in a reaction system and is prevented from being deposited on the surface of a reducing agent metal to cause reduction of the reducing capacity of the reducing agent metal. Compared with the traditional similar preparation reaction of biphenyl dianhydride, the reducing agent is close to quantitative reaction and is more suitable for industrialization.
- -
-
Paragraph 0015; 0027-0029; 0033-0035; 0036-0038
(2021/11/03)
-
- Method for preparing and separating and purifying biphenyl derivatives through catalytic coupling
-
The invention discloses a method for preparing and separating and purifying biphenyl derivatives by catalytic coupling, which mainly comprises the following steps: taking zinc as a reducing agent, carrying out cross-coupling to generate 3 - and 4 - biphenyldianhydrides in an aprotic solvent system and carrying out cross-coupling reaction under the ultrasonic-assisted catalysis to separate the prepared terphenyl derivatives. 3 3 ’ - 4 ’ - 4 ’ - The invention discloses a method for 3 preparing and 4 separating and purifying biphenyl derivatives by using zinc as a reducing agent 3 4 ’ . 3,3 ’ - And 4, 4 ’ - biphenyl derivatives, which are hydrolyzed and dehydrated to obtain three biphenyldianhydride isomer pure products respectively.
- -
-
Paragraph 0009; 0026; 0029; 0031; 0033; 0034; 0037
(2021/10/11)
-
- Preparation and separation method of biphenyldianhydride isomer
-
The method mainly comprises the following steps: taking nickel salt as a catalyst, coupling with zinc as a reducing agent, coupling with an aliphatic 3 - chloronaphthalimide and an aryl 4 - chlorosuccinimide mixture as a raw material to generate a biphenyl dianhydride derivative, and separating by using different solubility parameters and obtaining 3 and 4 ’ - respectively. 3,3 ’ - And 4, 4 ’ - biphenyl derivatives are hydrolyzed and dehydrated to obtain three biphenyldianhydride isomers, and the patent application is characterized in that a simple method for separating the three biphenyltetracarboxylic dianhydride intermediate is established.
- -
-
Paragraph 0024; 0027; 0028; 0031
(2021/10/05)
-
- Preparation method of 3, 3', 4, 4'-biphenyltetracarboxylic dianhydride
-
The invention discloses a preparation method of 3, 3', 4, 4'-biphenyltetracarboxylic dianhydride. The method includes the reactions of: (1) chlorination reaction: taking phthalic anhydride as the rawmaterial, adding a mixed solution of sodium hypochlorite aqueous solution and sodium hydroxide aqueous solution dropwise, carrying out chlorination reaction, and adjusting the pH value to generate 4-chlorophthalic acid monosodium salt; (2) coupling and hydrolysis: carrying out coupling reaction and hydrolysis reaction on the 4-chlorophthalic acid monosodium salt in the presence of a catalyst and acocatalyst under an alkaline condition to generate 3, 3', 4, 4'-biphenyltetracarboxylic acid sodium salt, wherein the catalyst is a palladium-carbon catalyst or a nickel-palladium-carbon catalyst, and the cocatalyst is hydroxylamine sulfate or hydroxylamine hydrochloride; and (3) acidification into 3, 3', 4, 4'-biphenyltetracarboxylic acid, and then drying and dehydration, thus obtaining 3, 3', 4, 4'-biphenyltetracarboxylic dianhydride. The method provided by the invention adopts phthalic anhydride as the raw material for reaction with sodium hypochlorite to synthesize 3, 3', 4, 4'-biphenyltetracarboxylic dianhydride, is low in production cost, avoids the use of potassium permanganate oxidation, simplifies the production process, and has small pollution, and high yield.
- -
-
-
- Synthesis method of 3,3',4,4'-biphenyltetracarboxylic anhydride
-
The invention discloses a synthesis method of 3,3',4,4'-biphenyltetracarboxylic anhydride, and belongs to the field of chemical synthesis. The synthesis method comprises the following steps: adding 4-bromo-o-xylene into magnesium powder and iodine (simple substance) to obtain a reactant; heating the reactant and 4-chloro-o-xylene to carry out reactions in the presence of nickel acetylacetone taken as the catalyst to obtain 3,3',4,4'-tetramethyl diphenyl, oxidizing and acidifying 3,3',4,4'-tetramethyl diphenyl to obtain 3,3',4,4'-biphenyltetracarboxylic acid, and finally carrying out high temperature dehydration to obtain 3,3',4,4'-biphenyltetracarboxylic anhydride.
- -
-
-
- Preparation method for biphenyltetracarboxylic dianhydride mixture
-
The invention relates to a preparation method for a biphenyltetracarboxylic dianhydride mixture. The preparation method comprises the following steps: with phthalic acid as a starting raw material, carrying out an electrophilic substitution reaction so as to produce a phthalic acid derivative; then subjecting the derivative to esterification so as to produce phthalate; further catalyzing phthalate and carrying out a coupling reaction so as to produce a biphenyl tetraformate mixture; and finally, successively carrying out saponification and acidification so as to produce the product biphenyltetracarboxylic dianhydride mixture. The method provided by the invention uses cheap and easily phthalic acid as the starting raw material and is a novel low-cost easily-operatable environment-friendly production method for biphenyltetracarboxylic dianhydride; moreover, isomeric compounds of all the biphenyltetracarboxylic dianhydride are synthesized at one time in the invention, so efficiency is improved and the cost is reduced.
- -
-
Paragraph 0030; 0031
(2016/10/09)
-
- METHOD FOR PRODUCING CARBOXYLIC ACID ANHYDRIDE, METHOD FOR PRODUCING CARBOXYLIC IMIDE, AND METHOD FOR MANUFACTURING ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER
-
A method for producing a carboxylic acid anhydride includes heating a composition containing a specific compound in a solvent to yield the carboxylic acid anhydride. The solvent is an aprotic polar solvent having a boiling point of 50° C. or more.
- -
-
Paragraph 0117
(2017/01/19)
-
- METHOD FOR PRODUCING MULTISUBSTITUTED BIPHENYL COMPOUND AND SOLID CATALYST TO BE USED THEREIN
-
A method for producing a multisubstituted biphenyl compound is represented by the following formula (2), including a step of coupling a substituted benzene compound represented by the following formula (1) in the presence of a solid catalyst with gold immobilized onto a support.
- -
-
Paragraph 0198
(2015/12/23)
-
- 3,4-DIALKYLBIPHENYLDICARBOXYLIC ACID COMPOUND, 3,4-DICARBOALKOXYBIPHENYL-3', 4'-DICARBOXYLIC ACID AND CORRESPONDING ACID ANHYDRIDES, AND PROCESSES FOR PRODUCING THESE COMPOUNDS
-
The present invention relates to the 3,4-Dicarboalkoxybiphenyl-3′,4′-dicarboxylic acid (including the corresponding acid anhydride) represented by the general formula (1): wherein R11 and R12 each represents an alkyl group having 1 to 4 carbon atoms, and n represents the number of waters of hydration that is 0 or 1.
- -
-
-
- Biphenyltetracarboxylic acid dianhydride and process for producing the same, and polyimide formed from the same and process for producing the same
-
To provide a process for producing BPDA whereby high productivity is attained while high purity is maintained. A process for producing biphenyltetracarboxylic acid dianhydride, which comprises heating biphenyltetracarboxylic acid to produce biphenyltetracarboxylic acid dianhydride, characterized in that the heating is carried out at a pressure of from 1×102 Pa to 1.1×105 Pa to a maximum temperature in a range of from 210° C. to 250° C. in such a manner that the temperature rising rate is higher than 50° C./hr for a period of at least ? of the time for the temperature rise from 60° C. to 210° C., and the temperature is maintained to be from 150° C. to 250° C. for from 0.5 to 10 hours.
- -
-
Page/Page column 13-14
(2010/12/29)
-
- Functionalized Photoreactive Compounds
-
The present invention concerns functionalized photoreactive compounds of formula (I), that are particularly useful in materials for the alignment of liquid crystals. Due to the adjunction of an electron withdrawing group to specific molecular systems bearing an unsaturation directly attached to two unsaturated ring systems, exceptionally high photosensitivities, excellent alignment properties as well as good mechanical robustness could be achieved in materials comprising said functionalized photoreactive compounds of the invention.
- -
-
-
- High-purity biphenyltetracarboxylic dianhydride and process for producing the same
-
There is provided biphenyltetracarboxylic dianhydride containing biphenyltetracarboxylic monoanhydride in an amount of not more than 0.4%. By using the biphenyltetracarboxylic dianhydride as a raw material, it is possible to produce polyimide or polyamic acid having an increased molecular weight.
- -
-
-
- Vapor-phase oxidation and oxidative ammonolysis of some methyl derivatives of biphenyl
-
Main pathways arc established of catalytic oxidative transformations of 3,4-di- and 3,3',4,4'-tetramethylbiphenyls in vapor phase. The possibility is analyzed of obtaining the corresponding anhydrides, imides, and nitriles of biphenylcarboxylic acids in yields of up to 59-69%.
- Shapovalov,Koshel',Sembaev,Postnova,Koshel'
-
p. 1386 - 1390
(2007/10/03)
-
- O-substituted N-hydroxy hindered amine stabilizers
-
Hindered amines based on various 2,2,6,6-tetraalkylated nitrogen-containing heterocyclic moieties wherein the hindered nitrogen atom on the ring is substituted with OR1 substituents and the 4-position of the ring is substituted with a variety of groups, are effective as light stabilizers in diverse substrate systems.
- -
-
-
- Palladium-Catalyzed Reductive Coupling of Aromatic Acid Dichlorides with Disilanes
-
Electron-deficient aromatic acid-chlorides are converted to biphenyl compounds by palladium-catalyzed reaction with disilanes.
- Krafft, Terry E.,Rich, Jonathan D.,McDermott, Philip J.
-
p. 5430 - 5432
(2007/10/02)
-
- Method for preparing biaryl compounds
-
An improved method for making biaryl compounds is disclosed, in which an aromatic acid halide having at least one strong electron-withdrawing group attached to or within the aromatic ring is reacted with at least one polysilane in the presence of an effective amount of a transition metal catalyst.
- -
-
-
- Process for producing biphenyltetracarboxylic dianhydrides
-
A process for separating and purifying biphenyltetracarboxylic dianhdride isomers from a mixture of these isomers by fractional crystallization in aliphatic acid anhydrides or acetone. The isomeric mixture is obtained by heating biphenyltetracarboxylic acids, optionally in the presence of an aliphatic acid anhydride. The biphenyltetracarboxylic acids are obtained by oxidizing coupling dimers of o-xylene or by hydrolyzing coupling dimers of dimethyl phthalate.
- -
-
-