386results about "Nitro compound preparation" patented technology

The invention relates to the technical field of nitrobenzene production, in particular to a method for preparing nitrobenzene by adopting a microreactor under a low-acid condition, the method for preparing nitrobenzene comprises the following steps: introducing a nitrating agent and raw material benzene into the microreactor for nitration reaction to obtain nitrobenzene, the microreactor is provided with at least four reaction modules which are connected in series, a nitrating agent and raw material benzene are fed into the first reaction module, and concentrated sulfuric acid is supplemented into at least one reaction module in other reaction modules except the first reaction module in the nitration reaction process; the effective concentration of sulfuric acid in the nitrating agent is not higher than 77%. The method for preparing nitrobenzene solves the production problems that benzene in a micro-reaction system is poor in reaction stability, incomplete in conversion and large in residual quantity in a low-acid environment, dinitration is affected, and the yield of waste acid is large. Finally, a mechanical application process of the dinitration waste acid and the acidic benzene is realized, the production process is safe and reliable, the operation flexibility is high, and the stability is high.

The invention provides a plate-type micro-channel reactor and a method for nitrifying trifluoromethoxybenzene by using the plate-type micro-channel reactor, and belongs to the technical field of organic synthesis. The plate type microchannel reactor comprises a first heat exchange plate, a reaction plate and a second heat exchange plate, the reaction plate is positioned between the first heat exchange plate and the second heat exchange plate; a feeding channel, a first shunting section, a first mixing section, a second shunting mixing section, a third shunting mixing section, a fourth shunting mixing section and a discharging channel which are connected in sequence are arranged on the reaction plate; and the feeding channel comprises a first feeding channel and a second feeding channel. According to the method, trifluoromethoxybenzene is taken as a raw material and is subjected to nitration reaction by using plate type micro-channel reactors connected in series, so that high-selectivity continuous nitration of trifluoromethoxybenzene is realized, the nitration reaction can be completed within 5 minutes, and the contents of byproduct meta-position and dinitrate can be controlled to be lower than 0.05% and 0.5% respectively.

The invention belongs to the field of organic chemical synthesis, and relates to a method for continuously synthesizing 1-nitroanthraquinone. A microreactor continuous flow circulation system is adopted, the raw material anthraquinone is prepared into slurry, and the slurry reacts with concentrated sulfuric acid with a set feeding flow in the continuous flow circulation system to realize continuous nitration of anthraquinone. The process for continuously synthesizing the 1-nitroanthraquinone by using the method is simple, the time is greatly shortened compared with that of a kettle type process, the requirement on equipment temperature control is lower, the solid slurry can continuously flow in the pipeline without blocking the pipeline, the reaction operability is improved, the product selectivity is good, and the raw material conversion rate is high. The microreactor continuous flow circulation system adopted by the invention has better mass and heat transfer efficiency, the reaction temperature control is more accurate, the explosion risk is reduced, and the operation process is safer.

The invention belongs to the technical field of energetic materials, and discloses a multi-nitro 1-bromine-3-fluoro-5-toluene energetic compound and a preparation method of the multi-nitro 1-bromine-3-fluoro-5-toluene energetic compound. According to the invention, 1-bromine-3-fluoro-5-toluene is taken as a raw material, the multi-nitro 1-bromine-3-fluoro-5-toluene energetic compound is prepared through a direct nitration reaction, the density of the compound is 1.80-2.03 g / cm < 3 >, the melting point is 50-108 DEG C, and the compound has the characteristics of high density, high energy, simple synthesis and the like, and is suitable for energetic plasticizers and casting carrier explosives.

The invention discloses a synthesis method of 2, 4, 5-trifluorophenylacetic acid, which comprises the following steps: by taking cheap and easily available o-chloronitrobenzene as a raw material, reacting with sodium nitrate in a sulfuric acid and trifluoroacetic acid system, separating generated 2, 4-dinitrochlorobenzene through melt crystallization, and continuing to synthesize 2, 4-dinitrochlorobenzene in methyl chloroacetate to obtain 2, 4, 5-trifluorophenylacetic acid. The method comprises the following steps: carrying out indirect aromatic nucleophilic substitution reaction on 2, 4-dinitrophenylacetic acid under the condition of sodium hydride to generate 5-chloro-2, 4-dinitrophenylacetic acid methyl ester, separating, carrying out fluorination reaction on the 5-chloro-2, 4-dinitrophenylacetic acid methyl ester and potassium fluoride under the action of a phase transfer catalyst, carrying out rectification separation to obtain 2, 4, 5-trifluorophenylacetic acid, and carrying out hydrolytic acidification on the 2, 4, 5-trifluorophenylacetic acid in a sodium hydroxide aqueous solution to obtain 2, 4, 5-trifluorophenylacetic acid. And the process route is safer, more environment-friendly, more efficient and lower in cost.

The invention discloses a synthetic method of 2-chloro-4-fluoro-5-nitrobenzoic acid. The synthetic method comprises the following steps: preparing a mixed acid of nitric acid and sulfuric acid; the method comprises the following steps: mixing 2-chloro-4-fluorotrichlorotoluene and mixed acid to carry out nitration reaction, heating the reaction system without separation after the nitration reaction is finished to carry out hydrolysis reaction, and obtaining the 2-chloro-4-fluoro-5-nitrobenzoic acid by a one-pot method. The synthesis method is high in conversion rate, good in yield, low in cost, simple in process, convenient to operate, free of separation and purification of intermediate products in the midway and easy to realize industrial production.

The invention discloses a diphenylpropane derivative and a preparation method and application thereof.The diphenylpropane derivative contains phenolic hydroxyl groups and amino groups, integrates the advantages of amino anti-aging agents and phenolic anti-aging agents, has high thermo-oxidative aging resistance and photo-oxidative aging resistance, can improve other properties of the anti-aging agents, and has a good application prospect. And compared with amine anti-aging agents, pollution is reduced, and the anti-aging agent is efficient, multifunctional, environment-friendly and low in pollution.

The invention discloses a continuous kettle type nitromethane production process, and relates to the technical field of basic chemical raw material synthesis and flow chemical reaction process control, which comprises the following steps: quantitatively and continuously pumping a temperature-regulated sodium nitrite mixed solution into a raw material mixer in a closed-loop automatic control mode through a variable-frequency feeding pump matched with a mass flow meter; synchronously, quantitatively and continuously pumping dimethyl sulfate into the raw material mixer in a closed-loop automatic control manner by matching a feeding pump with a stop valve and a mass flow meter, and uniformly mixing the two raw materials in the raw material mixer according to the stoichiometric molar ratio of the dimethyl sulfate to the sodium nitrite, according to the tandem type segmented design, each reaction kettle can be subjected to customized temperature field control and heat transfer design specially aiming at the special thermodynamic and dynamic requirements of the reaction stage where the reaction kettle is located, the heat transfer efficiency of the whole system is greatly improved, and due to the fact that reaction heat is taken away timely and accurately, the heat transfer efficiency is greatly improved. And a by-product generation path induced by local abnormal high temperature is effectively restrained.

The utility model relates to the technical field of reactors, in particular to a continuous multiphase reactor for anthraquinone nitration reaction, which comprises a reactor shell with a reaction cavity, a plurality of partition plates are arranged in the reactor, and the partition plates sequentially divide the reaction cavity into a first reaction area, a second reaction area, a settling area and a separation area from top to bottom. A valve is mounted on the partition plate; a first feeding hole for anthracene to pass through, a second feeding hole for sulfuric acid to pass through, a third feeding hole for nitric acid to pass through and a water inlet for a water solution to pass through are formed in the shell, and a first reaction zone, a second reaction zone, a settling zone and a separation zone are arranged in the shell of the reactor; the production of nitroquinone can be completed in one reactor, the integration degree is improved, the occupied space of equipment is reduced, and material circulation is avoided, so that the production efficiency is improved.

The utility model belongs to the technical field of nitration machines, and discloses a reactor internal structure for continuous nitration of dinitrotoluene, which comprises a heat exchange cylinder body which is a main body structure of a heat exchange device and is internally provided with a guide cylinder, and the guide cylinder is fixed between an upper tube plate and a lower tube plate and placed in the center of a stirring container. And the interior of the machine is divided into a stirring area with a stirrer and a circulating area which cannot be directly stirred by the stirrer. The baffle is arranged in the guide cylinder, so that the stirring strength can be increased by about 25%, and the reaction speed can be increased. The length of the baffle is consistent with that of the guide cylinder, but the baffle is not arranged at the stirring blade, a radial baffle is additionally arranged above the guide cylinder and below the liquid level, the radial baffle is connected with the machine wall to reduce the vortex of the liquid, and the baffle is welded with the baffle of the guide cylinder. The baffle plates are arranged in the heat exchange barrel and used for supporting the heat exchange tubes, relieving the stress condition of the heat exchange tubes, preventing fluid flowing from causing vibration of the heat exchange tubes, prolonging the length of a medium flow channel and improving the heat transfer efficiency.

The invention discloses a method for catalyzing carbon-hydrogen bond hydroxyl nitration of an aromatic compound by iron, which comprises the following steps: in a solvent, by taking nitrite as a nitro source, hydrogen peroxide as an oxidizing agent, iron as a catalyst and amino acid and derivatives thereof as ligands, catalyzing the aromatic ring of the aromatic compound to carry out carbon-hydrogen bond hydroxyl nitration reaction; the hydroxyl and nitro disubstituted aromatic compound is generated. According to the method, the hydroxyl and nitro disubstituted aromatic compound can be synthesized in one step, and the steps are simple and convenient; the used catalyst and oxidant are wide in source and low in cost; reaction conditions are mild, and selectivity is high; the nitro source is low in toxicity and high in safety; the functional group compatibility of the substrate is good, and the application range of the substrate is wide; the drug molecules and the drug molecule derivatives can be compatible, so that the hydroxyl nitration reaction of the aromatic compound is realized. According to the method disclosed by the invention, under optimized reaction conditions, the yield of the separated target product can reach 84%.

The invention discloses a preparation method of 3-amino-2-fluorobenzoyl halide (formula V). The method comprises two routes: a route I and # imgabs 0 # or a route II and # imgabs 1 #, wherein R, R1 and R2 are defined in the specification.

The invention discloses a method for reducing nitrides in waste acid based on a mixed dinitrobenzene preparation process, and relates to the technical field of mixed dinitrobenzene preparation. According to the method for reducing the nitrates in the waste acid based on the mixed dinitrobenzene preparation process, the mixed dinitrobenzene preparation process comprises first-stage nitration and second-stage nitration, and the waste acid is generated after the first-stage nitration; waste acid and benzene liquid are subjected to counter-current extraction in opposite flow directions through a filler layer, benzene is a continuous phase, and waste acid is a dispersed phase. According to the method, counter-current extraction is performed on the benzene liquid and the waste acid, the benzene liquid is a continuous phase, and the waste acid is a dispersed phase, so that nitrides in the waste acid are fully dissolved into the benzene liquid, the content of the nitrides in the waste acid after extraction is reduced, and the benzene liquid is continuously used as a raw material for preparing mixed dinitrobenzene.

The invention provides a method for preparing bisphenol nitro compounds by using a continuous tank reactor, and belongs to the field of continuous flow reaction. According to the method for preparing the bisphenol nitro compound by utilizing the continuous tank reactor, the bisphenol compound is used as a raw material, and the bisphenol compound and nitric acid are subjected to nitration reaction by utilizing the continuous tank reactor to prepare the bisphenol nitro compound. The nitration reaction can be realized with high efficiency and high selectivity, the reaction temperature can be effectively controlled, and the safety of the reaction is further ensured.

The invention relates to the technical field of chemical raw materials, and discloses a production process of p-nitrochlorobenzene, which comprises the following steps: carrying out nitration reaction on chlorobenzene and nitric acid as raw materials under the catalytic action of a catalyst to generate a mixture containing p-nitrochlorobenzene and o-nitrochlorobenzene, and carrying out post-treatment on the mixture of p-nitrochlorobenzene and o-nitrochlorobenzene to obtain p-nitrochlorobenzene. A p-nitrochlorobenzene product is obtained; according to the method, the chlorobenzene and the nitric acid are used as raw materials to be subjected to nitration reaction under the catalytic action of the catalyst, the p-nitrochlorobenzene product is obtained, energy consumption is low, pollution is avoided, and the obtained p-nitrochlorobenzene product is high in quality, purity and yield.

The application provides a method for continuously preparing nitrobenzene by using benzene and NO2 as raw materials. The method is characterized in that: a solid catalyst capable of catalyzing the nitration of benzene by NO2 is filled in a pipe reactor, benzene, NO2 and O2 are continuously fed into the pipe reactor at a certain flow rate, and the reaction is carried out at a certain temperature to obtain nitrobenzene. This route is safe, green, economical and efficient, and is a safe, green, economical and efficient nitrobenzene synthesis route.

The invention discloses a preparation method of 4-phenoxyphenylboronic acid, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: by taking diphenyl ether as a raw material, reacting with fuming nitric acid under the action of tris (pentafluorophenyl) boron, so as to generate a 4-nitrodiphenyl ether intermediate; generating 4-aminodiphenyl ether from the 4-nitrodiphenyl ether intermediate under the action of tetrahydroxy diboron and a catalyst, and then generating 4-phenoxyphenylboronic acid from the 4-aminodiphenyl ether and excessive tetrahydroxy diboron under the action of tert-butyl nitrite. In the first step of the route, the positioning selectivity of 4-position nitro is increased through specific Lewis acid, in the second step, nitro reduction and boronation are carried out through a continuous one-pot method, and the synthesis method of the compound is enriched.

The invention relates to a method for preparing an intermediate for synthesis of olpinapone. The method comprises the step of nitrating vanillic acid in anhydride by using a nitrating agent. The present invention also relates to an intermediate for the synthesis of olpiapone produced by this process. In addition, the present invention relates to a solution of an intermediate for the synthesis of olpiapone in an anhydride.

The invention relates to the field of chemical equipment, in particular to a 1-nitroanthraquinone continuous production process based on a dynamic liquid membrane continuous flow reactor, which comprises a solid feeding device, a homogeneous emulsifier, a quenching kettle, a solid-liquid separator, a centrifugal separator and a dynamic liquid membrane reactor, a sulfuric acid storage tank is divided into two branches through a sulfuric acid feeding pump, one branch is connected to the dynamic liquid membrane reactor, the other branch is connected to the dynamic liquid membrane reactor through a flow self-control valve, the quenching kettle is connected to a solid-liquid separator, the solid-liquid separator is divided into two branches, one branch is connected to an anthraquinone crude product storage tank, the other branch is connected to a centrifugal separator, and the other branch is connected to a gas-liquid separator. The centrifugal separator is divided into two branches, one branch is connected to the acid water storage tank, and the other branch is connected to the dichloroethane storage tank, so that the reaction selectivity of the anthraquinone nitration reaction can be effectively improved, high-viscosity solids are prevented from being blocked, and the conversion rate of raw materials in the continuous reaction of the anthraquinone nitration reaction is improved.

To provide an inexpensive, safe and industrial production method that substitutes a hydroxy group of a 2-hydroxymethylacrylate derivative with a fluorine atom.SOLUTION: A method for producing a compound represented by general formula (3) includes reacting a compound represented by general formula (1) with 1,1,2,2-tetrafluoro-N,N-dimethylethylamine in an organic solvent, where R1 is a cyclohexyl group, a naphthyl-1-yl group or the like, R2 is a methyl group or the like.SELECTED DRAWING: None

The invention discloses a preparation method of rosin-based polyamine, a product and application thereof, and belongs to the technical field of bio-based adhesives, the preparation method comprises the following steps: using toluene as a solvent, using thionyl chloride to carry out acylating chlorination on disproportionated rosin, after the reaction is finished, carrying out rotary evaporation to remove toluene, then reacting with methanol, and carrying out methyl esterification on the disproportionated rosin to obtain methyl esterified rosin; reacting the obtained methyl esterified rosin with acid to obtain nitrated rosin methyl ester; carrying out reduction reaction on the obtained nitrated rosin methyl ester and iron powder to obtain rosin-based polyamine; wherein the acid comprises one or more of nitric acid and sulfuric acid. The prepared rosin-based polyamine is synthesized into rosin-based isocyanate through a phosgenation method, and the rosin-based isocyanate is glued to prepare a shaving board, a fiberboard and a plywood with the thickness of 18 mm; the test method refers to GB / T17657-2013, and each performance of the artificial board meets the requirements of the national standard (P2 type in GB / T 4897-2015) (MDF-FN type in GB / T 18259-2018) (class II board in GB / T 18259-2009).

The invention relates to a process for producing nitrobenzene by an adiabatic nitration of benzene (2) and nitric acid (1) in the presence of sulfuric acid (7), the process comprising: (a) feeding benzene (2), nitric acid (1) and sulfuric acid (7) into a reaction zone (R); (b) producing a reaction mixture (4) comprising water, nitrobenzene and sulfuric acid by reaction of the benzene and the nitric acid in the presence of the sulfuric acid in the reaction zone (R); and (c) separating the reaction mixture into an aqueous phase (6) comprising water and sulfuric acid and an organic phase (5) comprising crude nitrobenzene by phase separation; wherein the concentration of titanium in the reaction mixture (4) is kept below 170 mg / kg.

The invention discloses a method for preparing nitro-mesitylene through a micro-channel nitration reaction. The method comprises the following steps: respectively conveying mesitylene, fuming nitric acid and sulfuric acid to a micro-channel reaction module through a metering pump, and completing nitration reaction within a retention time of tens of seconds to several minutes. The introduction sequence of nitration reaction materials, the reaction retention time and the reaction temperature are cooperatively controlled, the nitration reaction is completed in the microchannel reactor in a continuous flow mode, operation is easy and convenient, safety is high, efficient continuous production can be achieved, meanwhile, emission of three wastes is reduced, and the industrial application advantages of being environmentally friendly and economical are achieved.

This application belongs to the technical field of organic synthesis, and specifically discloses a method for nitrating aromatic compounds. Using unactivated aromatic compounds as raw materials, hexafluoroisopropanol which is easy to recycle as a solvent, and nitrate as a nitrating reagent, a nitrated aromatic compound can be obtained under relatively simple and mild conditions. In particular, this application can also be applied to the synthesis of dinitroaromatic compounds and the late-stage nitration modification of various drug molecules. This application avoids the use of corrosive acids and additional catalysts, and directly uses inexpensive and readily available nitrate as a nitrating reagent to achieve green nitration of unactivated aromatic compounds, which has important application prospects in the field of synthesizing aromatic nitro compounds, and also provides a new method for large-scale industrial production of nitroarenes.

A green synthesis method of nitrobenzene compounds, in an organic solvent, using aromatic amine as raw material, using an oxidant and a catalyst to form a reaction system, selectively oxidizing aromatic amine into corresponding nitrobenzene compounds, the method selects an oxidant which is green, pollution-free, the catalyst is common, easy to obtain, low in price, and has significant catalytic effect, and the reaction conditions are mild, simple in operation, low in cost, fast in speed, high in selectivity and high in product yield, which is a novel, good scientific research value and industrialization potential synthesis method of nitrobenzene compounds.

The invention provides a method for recovering nitric acid from nitrification waste acid and application. In the process of preparing dinitrotoluene DNT through primary nitration and secondary nitration processes, the method comprises the following steps: adding an intermediate nitration reaction, enabling a part of product nitrotoluene MNT separated after primary nitration to react with nitric acid in nitration waste acid separated after primary nitration, removing nitric acid in the nitration waste acid, and generating DNT; standing and layering the reaction liquid, and separating an organic phase containing dinitrotoluene DNT at the upper layer and a waste acid phase only containing sulfuric acid at the lower layer; an upper-layer organic phase enters a dinitration reaction unit for further reaction; the lower-layer waste acid phase is recycled to the primary nitration reaction unit and / or the secondary nitration reaction unit. According to the method, excessive nitric acid in the nitrification waste acid can be effectively recovered, DNT (Dinitrotoluene) dissolved and entrained in the nitrification waste acid is extracted, the excessive nitric acid in the waste acid is effectively recovered, the DNT removal process in the waste acid is simplified, and the problem that a heat exchanger is easily blocked by DNT is solved.

The invention relates to a separation and purification method in chemical production, and provides an energy-saving and efficient nitro-aromatic hydrocarbon separation and purification method. Gravity settling, alkali washing, cooling and filtering are combined, a liquid-liquid micro-mixer and cooling and filtering are used for replacing traditional tedious multi-stage neutralizing and water washing operation of a multi-kettle series connection or static mixer, impurities such as residual acid, phenols, sodium salt and water in the acidic nitro-aromatic hydrocarbon are efficiently removed, the emulsification phenomenon is avoided, and the quality of the acidic nitro-aromatic hydrocarbon is improved. And the treated material can ensure long-term stable operation of a subsequent rectification system. The method does not need a two-stage washing process in the prior art, and is low in material consumption, energy consumption and wastewater amount; the liquid-liquid mixer is used for the alkali washing process, and the alkali washing effect is remarkably improved; water and salts in the crude nitro-aromatic hydrocarbon are removed in one step in a fiber filter element cooling and filtering mode, and the separation efficiency is high; the whole set of separation and purification device is a totally-closed system device, is small in occupied area and simple to operate, and the purification effect is remarkably improved compared with a conventional process.

The invention discloses a chlorine-free synthesis method of 2, 4-dinitroanisole. The method comprises the following steps: by taking phenol as a raw material, carrying out first-stage and second-stage nitration in a microchannel or a tubular reactor to obtain 2, 4-dinitrophenol, then carrying out alkylation reaction on the 2, 4-dinitrophenol and an alkylation reagent under the action of an acid-binding agent, and carrying out filtration, rotary evaporation, precipitation, filtration, water washing and the like on a reaction solution to obtain a DNAN solid. According to the synthesis method, phenol is used as a raw material instead of chlorobenzene in a traditional process, chloride ions are not involved in the preparation process, corrosion to equipment is reduced, meanwhile, generation of a large amount of waste acid is avoided, and the three-waste treatment cost is reduced.

The invention relates to the technical field of fine chemical engineering, in particular to a continuous preparation process of nitrobenzotrifluoride, which at least comprises the following steps: S1, adding fuming nitric acid into sulfuric acid to obtain a mixed acid solution; s2, a metering pump is used for controlling the flow speed of the mixed acid solution and trifluorotoluene, the mixed acid solution and the trifluorotoluene sequentially pass through the two-stage dynamic tubular reactor, and the temperature of materials in the two-stage dynamic tubular reactor is controlled through external circulation; and S3, dropwise adding the mixture obtained after the reaction in the step S2 into water for quenching, then carrying out phase splitting, taking an upper-layer oil phase as a nitrobenzotrifluoride crude product, carrying out water washing and alkali washing to obtain nitrobenzotrifluoride, taking a lower-layer dilute sulphuric acid solution, further concentrating, and then applying in the next batch of nitration reaction, so that the online material quantity of the reaction is reduced, and the safety risk caused by thermal runaway of the reaction is avoided. Meanwhile, the concentration of sulfuric acid is reduced, so that the sulfuric acid is easier to recycle and reuse.

The invention discloses a preparation method of Linzagolix, which comprises the following steps: taking 2, 3-difluoro-6-methoxybenzyl alcohol as a raw material, under the action of alkali and phosphine ligand, carrying out Mitsunobu reaction on 2, 3-difluoro-6-methoxybenzyl alcohol and 2-methoxy-4-fluorophenol to obtain a compound A, sequentially carrying out nitration reaction and reduction reaction on the compound A to obtain a compound C, and carrying out recrystallization on the compound C to obtain the Linzagolix. Under the alkaline condition and the action of triphosgene, the compound C and 4-aminothiophene-2, 3-dimethyl dicarboxylate hydrochloride are subjected to a one-pot condensation reaction to obtain a compound D, and the compound D reacts under the alkaline condition to generate Linzaolix. According to the invention, the synthesis process of Linazagolix is shortened to five steps, the reaction condition is mild, the operation is simpler and more convenient, and the method is suitable for industrial production.