49 results about "Benzene synthesis" patented technology

The invention relates to a preparation method of a shape-selective catalyst used for a p-dialkyl benzene synthesis process, and relates to the technical field of preparation of a high-performance catalyst for an alkylation process. The preparation method comprises the steps of: weighing a metal nitrate, adding to absolute ethanol at a mass ratio of metal nitrate to absolute ethanol being 1:10 for completely dissolving, then adding a complex ligand at a molar ratio of the complex ligand to metal ions in the metal nitrate being (1:1)-(3:1), uniformly stirring, adding a microporous molecular sieve at a mass ratio of the metal ions in the metal nitrate to the microporous molecular sieve being (1:100)-(1:10), uniformly stirring, standing at room temperature for 24h, drying in a 60 DEG C water bath, then transferring to an oven, drying at 120 DEG C for 6h, baking in a muffle furnace, heating to 550 DEG C at a speed of 10 DEG C / min, and maintaining the temperature for 6h to obtain the required shape-selective catalyst. The preparation method is simple and low in cost; and the obtained shape-selective catalyst has high shape selective performance.

The invention relates to a combined nitrification method for synthesizing nitrobenzene and a combined device of a micro-reactor and a stirring reactor. During the synthesis, benzene and mixed acid of nitric acid and sulfuric acid are taken as initial materials, are conveyed to two inlets of the micro-reactor through a metering pump respectively, are premixed in micro-channels, and perform partialnitration reaction at the same time; and a first-stage nitration product with high dispersion state is produced at an outlet of the micro-reactor. The first-stage nitration product continuously flowsinto a stirred tank nitration reactor to continue to react. The method and the device perform continuous operation under the condition of the mixed acid with high water content and have safe process,the conversion rate of the benzene is 99.85 percent (mol), and the selectivity of a product, namely the nitrobenzene is 99.8 percent (mol).

The invention discloses an industrial production method of 1, 4-dibromo-2, 5-diiodobenzene, which belongs to the technical field of organic synthesis. The method comprises the step of carrying out iodination reaction at 68-72 DEG C under the action of trifluoroacetic acid and N-iodosuccinimide by using 1, 4-dibromobenzene as a raw material to obtain 1, 4-dibromo-2, 5-diiodobenzene. Compared with the existing 1, 4-dibromo-2, 5-diiodobenzene synthesis method, the method has the advantages that the use of concentrated sulfuric acid is avoided, the synthesis condition is mild, the operation is simple, the process is safe, and the industrial production is convenient.

The invention relates to a 1, 4-bis(chloromethyl)benzene synthesis technology and belongs to the technical field of organic chemical synthesis. The technology comprises that under LED light source irradiation, p-xylene and chlorine undergo a reaction in the presence of an ionic liquid catalyst to produce a 1, 4-bis(chloromethyl)benzene reaction solution, the 1, 4-bis(chloromethyl)benzene reaction solution is cooled and separated so that a 1, 4-bis(chloromethyl)benzene crude product is obtained, and the 1, 4-bis(chloromethyl)benzene crude product is subjected to vacuum rectification so that 1, 4-bis(chloromethyl)benzene is obtained. The 1, 4-bis(chloromethyl)benzene has a melting point of 98-101 DEG C and purity of 99% or more. The 1, 4-bis(chloromethyl)benzene synthesis technology is free of any solvent, guarantees high product purity, has the characteristics of high conversion rate, fast reaction rate and low cost and is suitable for industrial production.

The invention relates to a cyclohexylbenzene synthesis catalyst and a preparation method thereof, and a method for one-step synthesis of cyclohexylbenzene through benzene hydroalkylation. In the priorart, the yield of the by-product cyclohexane is high and the yield of the main product cyclohexylbenzene is low in the reaction due to the catalyst. A purpose of the present invention is mainly to solve the technical problems in the prior art. The technical scheme of the present invention is that the cyclohexylbenzene synthesis catalyst is used, and comprises a carrier and an active component supported on the carrier, the active component comprises a noble metal and manganese, the noble metal comprises at least one selected from iridium and palladium, and the carrier is selected from a hydrogen-type zeolite molecular sieve. The obtained catalyst can be used for one-step preparation of cyclohexylbenzene through benzene hydroalkylation.

The invention discloses a preparation method for a catalyst for catalytically oxidizing methylbenzene to compound benzaldehyde. The preparation method comprises the following steps: (1) dissolving melamine and urea in water and adopting a hydrothermal method and ultrasonic cooling for treating, thereby acquiring a precursor; (2) calcining the precursor under high temperature, thereby acquiring anultrathin N-doped nanosheet porous graphite phase carbon nitride material; (3) adopting a dipping method for loading a transition element oxide on the graphite phase carbon nitride material acquired in the step (2), thereby acquiring the catalyst. The transition element oxide loaded ultrathin N-doped nanosheet porous graphite phase carbon nitride catalyst prepared according to the invention is subjected to ultrasound-assisted hydro-thermal treatment, so that the agglomeration of nanosheet is restrained, the nanosheet distribution is uniform and the specific area is obviously increased, and meanwhile, more nitrogen vacant sites are generated by N doping, so that more reaction active sites are supplied for selective catalytic oxidation.

The invention relates to a method for preparing high-purity 2, 2'-dihydroxybiphenyl by taking dibenzofuran distillate as a raw material and belongs to the technical field of synthesis of 2, 2'-dihydroxybiphenyl. According to the method, dibenzofuran distillate (dibenzofuran content of 70-90%) extracted from wash oil is adopted as a raw material, and solid alkali sodium hydroxide, potassium hydroxide or a mixture thereof is adopted as an auxiliary material; the raw material reacts with the solid alkali sodium hydroxide, potassium hydroxide or the mixture thereof according to a feeding ratio of1: (0.5-2). The method comprises the following steps of: adding the dibenzofuran distillate into an alkali fusion reaction kettle; performing heating to 100-140 DEG C; adding the solid alkali, and performing slow heating; and distilling and extracting light components in the heating process. Compared with products obtained by other preparation processes of 2, 2'-dihydroxybiphenyl, a product obtained by the process of the invention is purer and does not contain salt impurities, so that the purity of the product is greatly improved; a large number of raw materials are saved, resource waste is avoided; a novel material processed by using the 2, 2'-dihydroxybiphenyl is better in using effect, and the forming effect of the produced novel material is better.

The invention provides a high-selectivity phenol synthesis method by benzoyl oxide. The method has the advantages of high selectivity, small energy consumption, and pollution free. The preparation method includes the steps of taking and dissolving cadmium salt and tungstate in amine solution; after evenly stirring and adjusting pH value, performing hydro-thermal treatment, centrifugation, filtering, washing, drying and other steps to obtain cadmium trngstate; taking and dissolving bismuth salt and tungstate in alcoholic solution; stirring and mixing evenly, and adding the prepared cadmium trngstate; then performing crystallization, cooling, filtering, separation, drying and other steps, and preparing the cadmium trngstate-bismuth tungstate composite photocatalyst; taking and dispersing the cadmium trngstate-bismuth tungstate composite photocatalyst in the solvent and reaction fluid; charging oxygen and lighting to obtain phenol. By controlling the mole ratio of bismuth and cadmium in the catalyst, the conversion rate of benzene is improved, and the selectivity of prepared phenol is more than 99%.

The invention relates to a catalyst for cyclohexylbenzene synthesis, and a preparation method thereof, and a method for one-step synthesis of cyclohexylbenzene through benzene hydroalkylation. In theprior art, the yield of the by-product cyclohexane is high and the yield of the main product cyclohexylbenzene is low in the reaction due to the catalyst. A purpose of the present invention is mainlyto solve the technical problems in the prior art. The technical scheme of the present invention is that the catalyst for cyclohexylbenzene synthesis is used, and comprises a carrier and an active component supported on the carrier, the active component comprises a noble metal and nickel, the noble metal comprises at least one selected from platinum and rhodium, and the carrier is selected from a hydrogen-type zeolite molecular sieve. The obtained catalyst can be used for one-step preparation of cyclohexylbenzene through benzene hydroalkylation.

The invention discloses a production process for synthesizing 3,5-Dibromonitrobenzene, relating to the technical field of chemical engineering. The production process comprises the steps of performing bromination reaction to obtain crude 2,6-dibromo-4-nitrobenzene; then, preparing nitride precipitates from crude 2,6-dibromo-4-nitrobenzene which is taken as a raw material, alcohol and benzene, and carrying out elimination reaction. The production process disclosed by the invention has the beneficial effects that the preparation is convenient, simple, environment-friendly and pollution-free, materials are easily available, the equipment investment is a little, the purity is high, the production process is convenient to operate, and prepared 3,5-dibromonitrobenzene is good in use effect and is safe and reliable.

The invention discloses a preparation method of 1-(β-D-glucopyranosyl)-4-methyl-3-[5-(4-fluorophenyl)-2-thienylmethyl]benzene. The method has the advantages of short route, no need for low temperature, solid starting materials and intermediates, convenient purification and good stereoselectivity.

The invention provides a synthesis method of tert-amylbenzene with controllable isomer content. The synthesis method comprises the following steps: 1) carrying out a substitution reaction on tert-amylalcohol and haloid acid to obtain a halopentane intermediate; 2) carrying out a Friedel-Crafts alkylation reaction on the halopentane intermediate and benzene under the catalysis of a Lewis acid to obtain tert-amylbenzene; wherein the Lewis acid is one of ZnCl2 and FeCl3 or a mixture of the ZnCl2 and the FeCl3; the temperature of the Friedel-Crafts alkylation reaction is -10 to 40 DEG C; the vacuum degree is absolute pressure of 2-75kPa; and the reaction time is 0.5-4 h. According to the synthesis method, by setting reasonable reaction steps, controlling reaction conditions, selecting a proper catalyst and the like, the isomerization ratio is reduced, and the tert-amyl product with high yield and high selectivity is obtained.

The invention discloses a method for synthesizing 4-hydroxymethyl-biphenyl, belonging to the field of organic synthesis. The method comprises the steps of enabling biphenyl, which is taken as a raw material, to react with NXS to generate 4-halogenated biphenyl; then, enabling the generated 4-halogenated biphenyl to react with magnesium metal in presence of chlorinated n-butane so as to generate aGrignard reagent; then, enabling the generated Grignard reagent to react with XCH2OR, and carrying out acidic hydrolysis to obtain the 4-hydroxymethyl-biphenyl. The method has the advantages of beingeasy in obtaining of raw material, low in cost and mild in conditions, thus having a process amplification prospect.

The invention provides a method for synthesizing 1-benzyloxy-2-[2-(3-methoxyphenyl)vinyl]benzene. The method comprises the following steps: making diphenylmethoxyphosphine react with m-methoxybenzyl chloride at 55-60 DEG C to obtain m-methoxybenzyldiphenylphosphine oxide; adding a solvent and a basifier into the m-methoxybenzyldiphenylphosphine oxide; and keeping reactions at room temperature to obtain 1-benzyloxy-2-[2-(3-methoxyphenyl)vinyl]benzene. The synthesis preparation method is simple, mild in reaction and easy to implement.

The invention relates to a catalyst for synthesis of cyclohexylbenzene, a preparation method thereof and a method of one-step synthesis of cyclohexylbenzene through hydroalkylation of benzene. The catalyst mainly solves the technical problems that yield of by-product cyclohexane is high and yield of main product cyclohexylbenzene is low in a reaction caused by a catalyst in the prior art. The catalyst for synthesis of cyclohexylbenzene comprises a carrier and the following active components: (1) 0.5-20g / L of Pd; and (2) 0-40g / L of at least one of lanthanoid elements, wherein the carrier is hydrogen-type zeolite molecular sieves. By employing the technical scheme, better effect is obtained, and the catalyst can be used to the one-step method of preparing cyclohexylbenzene through the hydroalkylation of benzene.