253results about "Nitro compound preparation" patented technology

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 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 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 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 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 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 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 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 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 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.

The invention provides a dynamic continuous flow synthesis process of 5-nitrosalicylaldehyde, which comprises the following steps: filling heteropoly acid loaded on spherical activated carbon into a dynamic continuous flow reaction tube, giving a certain external temperature, adding salicylaldehyde into an organic solvent, and reacting at a certain temperature to obtain the 5-nitrosalicylaldehyde. And simultaneously pumping the 5-nitrosalicylaldehyde and nitric acid into a dynamic continuous flow reaction tube filled with a heteropolyacid immobilized catalyst at a certain flow speed, and reacting to obtain the 5-nitrosalicylaldehyde. In the process of synthesizing the 5-nitrosalicylaldehyde, the raw material concentration, the raw material flow rate, the nitric acid flow rate and the reaction temperature are strictly controlled, so that a large amount of isomer impurities are prevented from being generated, the conversion rate during nitration is favorably improved, the reaction yield is improved, the wastewater discharge is reduced, and meanwhile, the safety risk of the traditional nitration kettle type reaction is reduced. Experimental results show that the yield of the 5-nitrosalicylaldehyde is 90% or above, and the purity of the 5-nitrosalicylaldehyde is 98% or above.

The invention discloses a preparation process of 3, 4, 5-trifluoroaniline, which comprises the following steps: by taking 1, 2, 3-trifluorobenzene as a raw material, firstly carrying out nitration reaction by using concentrated hydrochloric acid and concentrated nitric acid, then carrying out hydrogenation reaction under the action of a palladium carbon catalyst, and then separating to obtain the 3, 4, 5-trifluoroaniline with higher purity. The process has the advantages of easily available raw materials, simple production process, high product purity and low comprehensive cost, and is suitable for industrial production.

The invention provides a production method and production equipment of an aromatic nitro compound, and the production method comprises the following steps: carrying out nitration reaction on fuming nitric acid, a sulfuric acid-nitric acid mixed solution and aromatic hydrocarbon to obtain a nitration product crude product and waste acid; performing first-stage pickling on the nitration product crude product by using first pickling water to obtain a first-stage pickled crude product and first-stage yellow water; performing second-stage pickling on the first-stage pickling crude product by adopting second pickling water to obtain a second-stage pickling crude product and second-stage yellow water; mixing the first-grade yellow water with a nitric acid replenishing solution to obtain a sulfuric acid-nitric acid mixed solution, and returning the sulfuric acid-nitric acid mixed solution to the nitration reaction as a raw material; the second pickling water is concentrated wastewater generated by concentrating a byproduct dilute sulfuric acid in the preparation process of fuming nitric acid to form concentrated sulfuric acid; the first pickling water is a mixed solution formed by mixing secondary yellow water and sulfuric acid. The production method is good in operation stability, simple in technological process and low in cost.

The invention belongs to the technical field of deuterated organic chemical synthesis, and particularly relates to a synthetic method of deuterated m-dibromobenzene-D4, which comprises the following steps: a, nitration reaction of deuterated benzene: enabling the deuterated benzene to react with mixed acid to generate deuterated nitrobenzene; b, performing bromination reaction on the deuterated nitrobenzene: reacting the deuterated nitrobenzene with liquid bromine by taking iron tribromide as a catalyst to generate deuterated m-bromo nitrobenzene; c, carrying out reduction reaction on the deuterated m-bromonitrobenzene: converting the deuterated m-bromonitrobenzene into deuterated m-bromoaniline by taking biboric acid as a reducing agent; and d, diazotization reaction of the deuterated m-bromoaniline: enabling the deuterated m-bromoaniline to react with cuprous bromide to generate the target product deuterated m-dibromobenzene. The deuterated m-dibromobenzene-D4 product with high purity and deuterated rate is prepared by the synthetic method, the process is simple, the raw materials are low in price and easy to obtain, and the application of the deuterated halogenated aromatic hydrocarbon serving as an intermediate in synthesis in the fields of organic photoelectricity and deuterated medicines is expanded.

The present application relates to a kind of raw material benzene p-nitrobenzene hydrogenation catalyst influence evaluation method, comprising the following steps: raw material benzene is purchased, and heavy component monitoring index is increased, and heavy component is directly used in nitration and hydrogenation process when lower than certain content;Heavy component is higher than certain content, and raw material benzene needs to be concentrated, and the influence on hydrogenation catalyst activity is evaluated, and raw material benzene use and processing scheme are formulated according to the evaluation result.The present application also relates to a kind of aniline production method.The present application can effectively prevent the material of entraining toxic catalyst in raw material benzene, along with nitrobenzene into hydrogenation reactor, effectively avoid catalyst activity reduction, cause hydrogenation reaction parameter to fluctuate sharply, and then lead to catalyst consumption sharp increase, when serious, can cause system catalyst overall deactivation, improve the stability of production process.

The invention discloses a preparation method of a mesalazine intermediate, which comprises the following steps: carrying out nitration reaction by using 2-chlorobenzoic acid as an initial raw material, and hydrolyzing in an alkaline aqueous solution to obtain a synthetic intermediate 5-nitrosalicylic acid of mesalazine. The method is mild in process condition, the used raw materials are cheap and easy to obtain, dangerous and toxic reaction conditions are not involved, the content of 3-site isomer impurities in the intermediate 5-nitrosalicylic acid product is 5% or below, and the total content of other impurities is lower than 0.5%.

The invention belongs to the field of organic synthesis, and particularly relates to a method for synthesizing 1-nitroanthraquinone by a high-speed sheet-shaped horizontal reactor. Specifically, anthraquinone is taken as a substrate, and 1-nitroanthraquinone is generated through nitration in a high-speed sheet-shaped horizontal reactor. The device has the beneficial effects that the heat exchange area is increased, so that the nitrification heat exchange efficiency is high, and the nitrification is thorough; the problems of blockage of a continuous flow reactor, explosion easily caused by excessive temperature accumulation of a kettle type reactor, high nitrate concentration on the surface and non-uniform reaction of upper and lower layers are avoided, and the reactor is better suitable for viscous materials; the temperature of the cooling liquid of the high-speed sheet-shaped horizontal reactor is close to the reaction temperature, so that smooth reaction is guaranteed, and explosion caused by sudden reaction due to sudden reaction caused by accumulation of reactants to a certain amount due to reaction stop caused by too low temperature of a reaction medium is avoided.

The invention discloses a supergravity dynamic tubular nitration reaction device which comprises a shell, a motor, an output rotating shaft, a sealing fin, a filler, a spiral blade, a mixed acid material inlet, a reactant inlet, a product outlet, a heat exchange jacket, a heat exchange medium inlet and a heat exchange medium outlet, the invention further discloses a nitration reaction method of the reaction device. According to the reaction device, a good material mixing effect is achieved through the strong shearing effect of the filler rotating at a high speed in the supergravity device on materials, and the product selectivity is improved; however, the problems of short material retention time and insufficient reaction when a supergravity reactor is independently used for carrying out the reaction exist in the prior art, and the device innovatively proposes that a dynamic pipe is combined at the lower end of the supergravity reactor to reasonably control the material retention time and improve the conversion rate of reactants.

The present application relates to the technical field of chemical production, and discloses a method and device system for continuously producing nitrochlorobenzene and application thereof. In the method, mixing of reaction raw materials and reaction are completed in steps, so that the defect of too severe heat release, too high temperature, side reaction and safety problem caused by direct reaction is avoided. Meanwhile, by controlling the volume flow ratio of nitric acid and chlorobenzene feed, the raw material conversion rate and the yield of the target product are improved, and the proportion of p-nitrochlorobenzene in the product is also increased, so that the economic benefit is improved. In addition, the method provided by the present application does not need concentrated sulfuric acid as a catalyst, so that the problem of difficult treatment of waste sulfuric acid is solved, and the environmental protection of nitrochlorobenzene production is improved.