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47 results about "1,2-Dichlorobenzene" patented technology

1,2-Dichlorobenzene, or orthodichlorobenzene (ODCB), is an organic compound with the formula C₆H₄Cl₂. This colourless liquid is poorly soluble in water but miscible with most organic solvents. It is a derivative of benzene, consisting of two adjacent chlorine atoms.

Method for preparing chlorobenzene, p-dichlorobenzene and o-dichlorobenzene in benzene chlorination

The invention discloses a method for preparing chlorobenzene, p-dichlorobenzene and o-dichlorobenzene in benzene chlorination, and relates to a preparation method of chemical raw materials. The method comprises the following steps: continuously introducing dry benzene and chlorine with a high activity and high p-dichlorobenzene selectivity catalyst into an outer circulation reactor, wherein the benzene and chlorine need sufficient retaining time, reacting at a set temperature to prepare p-dichlorobenzene, obtain o-dichlorobenzene at the same time and co-produce chlorobenzene, preparing dichlorobenzene by using the outer circulation reactor and taking the benzene and the chlorine as raw materials and metal sulfide as a catalyst, at the same time co-producing chlorobenzene, forming circulation of the materials through the introduced nitrogen and generated hydrogen chloride as power so as to obtain good stirring for prompting mixing, diffusion, heat conduction and mass transfer of the reactants. The method is rapid in reaction speed, high in capacity, large in ratio of p-dichlorobenzene and o-dichlorobenzene, free of polychlorobenzene byproduct, and high in flexibility and operation flexibility as the ratio of the chlorobenzene to the dichlorobenzene in a product can be adjusted according to demands.
Owner:LIAONING FANGDA ENG DESIGN CO LTD

Method for producing 2,4-dichloroacetophenone by using solid waste chlorobenzene tar as raw material

The invention discloses a method for producing 2,4-dichloroacetophenone by using solid waste chlorobenzene tar as a raw material. The method mainly comprises the following steps of: extracting m-dichlorobenzene from the solid waste chlorobenzene tar, and then performing five steps of acylation, washing, distillation, crystallization and packing in the 2,4-dichloroacetophenone production process. The method is characterized in that: the acylation reaction comprises that: the m-dichlorobenzene and acetyl chloride undergo the acylation reaction under the action of anhydrous aluminum trichloride, the dripping temperature of the acetyl chloride is kept between 50 and 60 DEG C during reaction, the temperature is gradually raised to between 90 and 95 DEG C after the dripping is finished, and reflux stirring reaction is performed for about 4 hours to obtain the 2,4-dichloroacetophenone. The method has the advantages that: the m-dichlorobenzene is reclaimed from the solid waste chlorobenzene tar during production, and the reclaimed m-dichlorobenzene is used as the raw material for producing the 2,4-dichloroacetophenone, so by the method, the 2,4-dichloroacetophenone is produced by using the m-dichlorobenzene as the raw material while extra worries of m-dichlorobenzene and o-dichlorobenzene production enterprises are solved, the supply and demand pressure of chlorobenzene markets is relieved and extended products are further developed and utilized.
Owner:JIANGSU LONGCHANG CHEM

Aqueous-phase synthesis method of chlorpyrifos by using trichloro-acetic chloride as initial material

The invention discloses an aqueous-phase synthesis method of chlorpyrifos by using trichloro-acetic chloride as an initial material. The method comprises steps of: reacting trichloro-acetic chloride, acrylonitrile, orthodichlorobenzene and a compound catalyst to obtain a 3,5,6-Trichloropyridin-2-ol sodium crude product; adding the 3,5,6-Trichloropyridin-2-ol sodium crude product into a reaction kettle with water, a catalyst and alkali, heating for reflux for 3 h, standing to separate out a solvent, and cooling, crystallizing and filtering an aqueous-phase to obtain the 3,5,6-Trichloropyridin-2-ol sodium; and adding water into the reaction kettle, adding a dispersing agent, 3,5,6-Trichloropyridin-2-ol sodium, ethyl chloride and a catalyst with stirring, reacting, cooling, crystallizing, washing and conducting suction filtration to obtain a chlorpyrifos active compound product. The invention employs trichloro-acetic chloride as the initial material to produce high-purity 3,5,6-Trichloropyridin-2-ol sodium, which is used directly as a raw material for the synthesis of chlorpyrifos. The sodium alkoxide produced by the method does not require refining, purifying or drying; water is used as the medium; and reaction materials are added at once for synthesis of chlorpyrifos. The method has advantages of simpleness, easy operation, environmental protection, energy saving, increased product yield, and improved product purity.
Owner:JIANGSU QIHENG AGRI & CHEM TECHCO

Method for preparing maleimide stop end type polyimide resin

The invention relates to a method for preparing maleimide stop end type polyimide resin, comprising the following steps: diamine, maleic anhydride and tetracarboxylic dianhydride are sequentially added to a polar solvent according to a molar ratio of (n+1):2:n to have the solid content of 25 plus or minus 1 percent (gram/milliliter) and then stirred for 8-24 hours at room temperature under the protection of nitrogen to generate intermediate polyamide acid, then a dehydrating agent acetic anhydride, a dehydrating catalytic agent triethylamine and the polar solvent are added into the intermediate polyamide acid so that the solid content is reduced to 15 percent (gram/milliliter) and then chemical imidization for 4-6 hours is conducted under the temperature of 30 DEG C-80 DEG C, then reaction liquid is poured into anhydrous ethanol which is stirred at high speed to obtain deposits, and the deposits are sequentially and sufficiently washed by the anhydrous ethanol and anhydrous ether and then dried in vacuum so as to obtain the maleimide stop end type maleimide polyimide resin, or heat dehydration cyclizing is conducted on the generated intermediate polyamide acid under the action of entrainer ortho-dichlorobenzene and chlorobenzene or methylbenzene to obtain outcomes of the maleimide stop end type maleimide polyimide resin.
Owner:华烁电子材料(武汉)有限公司

Method for preparing dichlorobenzene and trichlorobenzene and increasing para-ortho ratio

The invention provides a method for preparing dichlorobenzene and trichlorobenzene and increasing the para-ortho ratio, and is characterized in that a chlorination reaction takes benzene or chlorobenzene as a raw material; a continuous chlorination reaction is carried out in the presence of a main catalyst and an auxiliary agent, through a ring type continuous chlorination reactor or a multi-stage series-connection kettle type reactor and under the conditions of the reaction temperature of 50-120 DEG C and the reaction pressure of -0.05-0.5 MPa; and a reaction liquid passes through a membrane filtration system, the main catalyst remains in the reactor for reaction, a dichlorobenzene clear liquid after filtration is subjected to light component removal, rectification and crystallization to obtain dichlorobenzene, orthodichlorobenzene, 1,2,3-trichlorobenzene and 1,2,4-trichlorobenzene finished products. Compared with a conventional dichlorobenzene preparation process, the method has the dichlorobenzene para-ortho ratio greatly increased to 8.5 and the trichlorobenzene para-ortho ratio greatly increased to 13.6, and has the advantages of low use cost of the catalyst auxiliary agent, continuous production realization, good product selectivity and the like.
Owner:JIANGSU YANGNONG CHEM GROUP +2

Method and specially used apparatus for ortho-dichlorobenzene continuous mononitration reaction

InactiveCN107417536APrecise control of reaction parametersOvercome problems such as uneven local concentrationProcess control/regulationChemical/physical/physico-chemical stationary reactorsNitrationMetering pump
The invention discloses a method and specially used apparatus for ortho-dichlorobenzene continuous mononitration reaction. The method is characterized in that raw materials are added into an ortho-dichlorobenzene metering tank; a nitrating agent A is added into a nitrating agent A metering tank; the raw materials and the nitrating agent A are separately input into a first mixer synchronously through a first metering pump and a second metering pump; a reaction is performed at a temperature of 100-200 DEG C for 15-50 min; a reaction solution A enters a first liquid separation device; after liquid separation, an organic phase A enters a second mixer and an inorganic phase A enters a waste acid receiving device; a nitrating agent B stored in a nitrating agent B metering tank is added into the second mixer through a third metering pump; a nitration reaction is performed in a second tube reactor at a temperature of 10-100 DEG C; a reaction solution B enters a second liquid separation device; after liquid separation, an inorganic phase B enters the waste acid receiving device and an organic phase B enters a product postprocessing device for obtaining a mononitration product. The concentration of sulfuric acid used in the preparation method provided by the invention is low, the raw material conversion is complete, the yield of the final product is high, multi-nitro by-products are less, and the safety is higher, so that the preparation method and the apparatus are suitable for industrialized production.
Owner:ZHEJIANG UNIV OF TECH

Method for synthesizing and preparing o-phenylenediamine from orthodichlorobenzene

The invention relates to a method for synthesizing and preparing o-phenylenediamine from orthodichlorobenzene. The method for synthesizing and preparing o-phenylenediamine from orthodichlorobenzene comprises the following steps: putting orthodichlorobenzene, a copper catalyst and a ligand into an autoclave according to a molar ratio of 1:(0.25-5%):(0.25-5%), and then adding liquid ammonia or ammonia water into the autoclave, wherein the molar ratio of the added liquid ammonia or ammonia water to orthodichlorobenzene is (2-20):1; reacting for 2-36 hours while the reaction temperature is controlled to be 20-300 DEG C and the reaction pressure is controlled to be 1-10MPa; and finally, discharging while the inner temperature is controlled to be 90-100 DEG C, transferring into a distillation still, and carrying out vacuum distillation, so that white o-phenylenediamine is obtained. The method for synthesizing and preparing o-phenylenediamine from orthodichlorobenzene has the advantages that orthodichlorobenzene is taken as a raw material, direct amination is carried out to obtain o-phenylenediamine, a high power-supply ligand is adopted for improving the activity of the copper catalyst, the reaction difficulty is reduced, reaction conditions are mild, the reaction efficiency and reaction yield are obviously improved, and thus the method is applicable to industrial production.
Owner:江阴市华亚化工有限公司
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