60 results about "P-chlorotoluene" patented technology

The present invention relates to a catalyst for preparation of p-chlorobenzaldehyde through liquid phase catalytic oxidation. The catalyst is a compound catalyst, which is formed by loading an element provided with catalytic activity on a carrier of aluminum oxide. Active componentS of the catalyst of the present invention are cobalt and manganese, which are loaded on the carrier of the aluminum oxide. The molar ratio of cobalt and manganese is 0.1-5. In addition, the active components of the present invention can also comprise nickel, copper, iron, cerium, lanthanum, magnesium or zirconium and bromine, besides cobalt and manganese. The catalyst of the present invention is applied the reaction course for preparation of p-chlorobenzaldehyde, and is characterized by the simple technique, the high p-chlorobenzaldehyde reaction yield ratio, the low reaction temperature, the simple catalyst separation, and so on.

The invention discloses a separation method of p-chlorotoluene and o-chlorotoluene. A bis-diethoxy column [n] arene crystal material is utilized to adsorb and separate a p-chlorotoluene and o-chlorotoluene mixture, and the chemical structural formula of the bis-diethoxy column [n] arene crystal material is as shown in the specification, wherein n is 5 or 6. The separation method has simple separation process operation and low equipment requirement. No rectification operation is required in the separation process, the energy consumption is low, the energy is saved, and the production cost of the p-chlorotoluene is reduced. The crystal material used has high stability, and can be recycled, and the separation effect cannot be reduced.

The invention relates to a process for preparing 2, 4-dichlorotoluene by using p-chlorotoluene, chlorine as raw material for synthesizing 2, 4-dichlorotoluene through catalyzed chloridization, which comprises the steps of synthesizing, alkaline cleaning, rectifying, the synthesizing reaction temperature is between 35-45 deg. C, the alkaline cleaning agent for washing synthetic reaction product in the alkaline cleaning step is sodium carbonate crystal containing crystal water. The invention increases the yield of 2, 4-dichlorotoluene and improves the chlorine distribution status during reaction.

The invention discloses a method for preparing p-chlorobenzaldehyde, which comprises the following steps: reacting p-chlorotoluene with chlorine in the presence of an initiator under the irradiation of a mercury lamp at the chlorination temperature of 90-140 DEG C to obtain a p-chlorobenzyl chloride/p-trichlorotoluene mixture; and while controlling the average chlorination degree at 1.4-1.6, carrying out catalytic hydrolysis in a 3-6 wt% nitric acid solution for 6-12 hours to obtain the p-chlorobenzaldehyde. By using the method disclosed by the invention, the next hydrolysis step can be directly carried out without separating the intermediate; and thus, the method is simple in technique and can easily implement industrialized production.

The invention provides a novel method for preparing o-chlorotoluene through chlorinating toluene. The technical scheme is as follows: the method comprises the steps of taking a mixture of elemental iodine and iron powder as a catalyst under dark conditions, adding the catalyst into a toluene solution, slowly introducing chlorine gas, controlling the temperature of a whole chlorination process to be 40-50 DEG C, and controlling an introduced chlorine gas volume so as to enable the toluene conversion ratio to be not lower than about 99%. According to the method, after the catalyst is applied to toluene chlorination, the percent content of o-chlorotoluene in a product is increased effectively, the content ratio of o-chlorotoluene to p-chlorotoluene reaches 2.0, the content of m-chlorotoluene is lower than 0.2%, and the total content of poly-chlorotoluene is lower than 5.0%.

The invention belongs to the field of water treatment technologies, relating to a preparation method of a carbon based nano-iron alloy water treatment material by utilizing carbon based nano-iron alloy to activate hypochlorous acid and hypochlorite, and generate chlorine radical and hydroxyl radical to remove p-chlorotoluene. The preparation method comprises the following steps: 1) an activation process of granular active carbon; the granular active carbon is activated by adopting a boiling water activation method; 2) nano-iron alloy is loaded in the activated granular active carbon; inorganic iron salt and activated active carbon are mixed according to the iron-carbon mass ratio of (1:1) to (1:5), nickel chloride or palladium acetate is mixed with the inorganic iron salt, and the molar ratio of the nickel chloride or the palladium acetate to iron in ferric salt is (1:5) to (1:10), then iron alloy is produced by being reduced by adopting a potassium borohydride liquid phase method and is loaded on the granular active carbon. The material obtained by the invention has less secondary pollution in a water treatment process, good treatment effect, and is liable to be realized.

The invention discloses a preparation method for 2-cyano-4'-methylbiphenyl. The invention adopts the following technical scheme: the preparation method comprises the following steps: taking p-chlorotoluene as a raw material for Grignard reaction with magnesium powder in a solvent in the absence of water under nitrogen protection, and coupling a reaction product with chlorobenzonitrile under the catalytic effect of a nickel-manganese composite catalyst to prepare 2-cyano-4'-methylbiphenyl. A Ni (II)/Mn (II) composite catalyst is added into a 2-cyano-4'-methylbiphenyl synthesis reaction system, so that the reaction activity is enhanced and the reaction selectivity is improved; the catalyst is lower in price and easy to recover, so that the postprocessing difficulty is lowered and the production cost is reduced; a recrystallization method is adopted in postprocessing and refining processes, so that the product purity is further improved, a white product is obtained, and the industrialization operation is more convenient.

The invention belongs to the field of chemical industry and relates to a mixed chlorotoluene MVR (mechanical vapor recompression) rectification system and method. The system herein comprises a primarycolumn, an ortho-column, a para-column, evaporators, a cooler, a gas-liquid separation tank, a vapor compressor, reboilers and the like. The system is characterized in that continuous rectification via the primary column, ortho-column and para-column by means of rectification is carried out; mixed chlorotoluene mother liquor that is preheated is processed via the primary column to obtain crude o-chlorotoluene and p-chlorotoluene; the crude o-chlorotoluene and p-chlorotoluene are fed respectively into the ortho-column and the para-column for continued rectification; o-chlorotoluene with purityof higher than 98% is acquired from the top of the ortho-column; p-chlorotoluene with purity of higher than 92% is acquired from the bottom of the ortho-column; distillates from the three columns aresubjected to heat exchanging with liquid water in respective top evaporators; the liquid water absorbs heat and evaporates into water vapor; the water vapor is separated and purified by the gas-liquid separation tank before the resultant is heated and pressurized in the vapor compressor; the pressurized material enters the reboilers at the bottoms of the three columns to release latent heat to heat part of the bottom distillates. The system and method herein have the advantages of high separation efficiency, low energy consumption, low operation cost and the like.

The invention relates to a method for preparing p-chlorobenzaldehyde through continuous oxidization of p-chlorotoluene and belongs to the technical field of organic synthesis processes. The method is a process technology for preparing p-chlorobenzaldehyde by continuously oxidizing p-chlorotoluene in a tubular reactor with a p-chlorotoluene compound as a raw material, one or more metal ion complexes of cobalt, molybdenum and bromine as a catalyst, hydrogen peroxide as an oxidizing agent and acetic acid as a solvent. The method has mild conditions and takes short time, the utilization rate of the raw material is high, effective control in the reaction process can be realized, safe, stable and continuous operation is realized, and the production efficiency is high.

The invention discloses an automatic temperature control reaction kettle for synthesizing p-chlorotoluene. The reaction kettle comprises a lower-part stirring paddle, an upper-part stirring paddle, astirring shaft, a water drainage valve, a circulating water valve, a water pump, a controller 1, a heating water tank, an air inlet pipe, an electric valve, a water inlet pipe, a water outlet pipe, afirst water inlet valve, a second water inlet valve, a chlorine gas inlet, a gas distributor, a material inlet pipe, a liquid raw material inlet, a coil water inlet, a gas outlet, a safety valve, a coil water outlet, a motor, a motor reducer, a coil, a liquid outlet, a temperature sensing device, a reaction kettle body, a sealing cover, a sealing ring, a mounting mouth, a jacket, a jacket water inlet, a jacket water outlet, a hot water valve, a cold water valve, a cold water inlet pipe and a controller 2. An automatic temperature control device including the jacket and the coil is adopted by the reaction kettle, so that the problems of too low selectivity caused by excessively high reaction temperature and a too-low conversion rate caused by excessively low reaction temperature are solved,and meanwhile full contact of reactants are achieved through adoption of the two stirring paddles and the gas distributor.

The present invention provides a method for preparing biphenyl 4,4'-dicarboxylic acid, and belongs to the technical field of organic synthesis. The method comprises: adopting p-chlorotoluene as a raw material, adding a metal magnesium, a catalyst and a ligand, and synthesizing 4,4'-dimethylbiphenyl through a one-pot method; and introducing oxygen to the 4,4'-dimethylbiphenyl to carry out oxidation, adding a certain amount of the catalyst, adopting acetic acid as a solvent, heating, evaporating the solvent after completing the reaction, and carrying out water washing and drying to obtain the biphenyl 4,4'-dicarboxylic acid. According to the present invention, the p-chlorotoluene is adopted as the starting material, the solvent-free one-pot method is adopted to synthesize the 4,4'-dimethylbiphenyl so as to provide advantages of low cost, high yield, simple operation and easy purification; free radical oxidation of oxygen molecules is adopted in oxidation of aromatic hydrocarbon alkyl into aromatic carboxylic acid, such that reaction conditions are relatively mild, and corrosion on the equipment is reduced; and the method is suitable for industrial production.

The invention discloses a method for selectively preparing o-chlorotoluene, which is characterized in that a mixture of iron powder and a dibenzothiophene compound is used as a combined catalyst, and chlorine is introduced into toluene under a dark condition to obtain o-chlorotoluene. The temperature in the chlorination process is controlled to be 30-50 DEG C, and the conversion rate of toluene is 98-100% by controlling the chlorine introduction amount. The chlorination liquid obtained after the catalyst is applied to toluene chlorination takes o-chlorotoluene as a main product, the percentage content of o-chlorotoluene is effectively increased, the highest content of o-chlorotoluene reaches 68.50%, the content of m-chlorotoluene is smaller than 0.15%, the content of total dichlorotoluene is smaller than 2.21%, and the mass ratio of o-chlorotoluene to p-chlorotoluene reaches 2.28.

The invention discloses a method and a device for continuously producing sartan biphenyl. The method comprises the following steps: carrying out continuous Grignard reaction on p-bromotoluene or p-chlorotoluene by adopting a fixed bed reactor; carrying out continuous coupling reaction on the obtained Grignard reagent and o-chlorobenzonitrile in a fixed bed reactor with a solid supported catalyst;finally, preparing the sartan biphenyl. Materials are added and output in a continuous manner in the whole reaction process after the production is started; the solid supported catalyst is spherical silica gel supported monoatomic Mn (0) and Zn (0) catalyst. The invention has the characteristics of continuous and stable production, timely transmission of reaction heat, no temperature runaway and deflagration problems, high reaction safety, reduction of reaction byproducts, and high product yield and efficiency.

The invention discloses a preparation method of parachlorobenzoyl chloride. The method includes the steps of: (1) chlorination: adding the raw material p-chlorotoluene into a reaction kettle, performing stirring, adding triethanolamine into the reaction kettle, and conducting stirring for 30min, adding thionyl chloride, conducting stirring for 10min, then slowing raising the temperature, adding azodiisobutyronitrile, introducing chlorine gas for reaction to obtain 4-chlorobenzotrichloride; (2) hydrolysis: adding the4-chlorobenzotrichloride obtained in step (1) into a hydrolysis kettle, adding the catalyst ferric trichloride, adding water dropwise to obtain a parachlorobenzoyl chloride crude product; and (3) distillation: distilling the parachlorobenzoyl chloride crude product to obtain the product. Specifically, the p-chlorotoluene is 30000-40000 parts, and triethanolamine is 1-10 parts. P-chlorotoluene is adopted as the raw material for chlorination by chlorine gas to obtain 4-chlorobenzotrichloride, and then hydrolysis and distillation are carried out so as to obtain the product. Firstly triethanolamine is utilized to remove the influence of iron ions, then thionyl chloride is utilized to remove the moisture influence, the chlorination reaction time is short, the reaction by-product is few, and the yield is high.