200results about "Nitro compound preparation" patented technology

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 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.

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.

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 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 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 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.

The application discloses a preparation method of a modified mordenite catalyst, the catalyst prepared by the method, and application of the catalyst. The preparation method comprises the following steps: 1) adding mordenite into acid, soaking, and roasting to obtain acid-modified mordenite; 2) fully contacting the acid-modified mordenite with TiCl4 vapor to obtain Ti-modified titanium mordenite; 3) mixing the Ti-modified titanium mordenite with tungsten metal salt, zirconium metal salt and molybdenum metal salt in a solution, adding ammonia water to age, filtering out solid, and washing, drying and roasting the solid to obtain a supported catalyst; and 4) immersing the obtained supported catalyst in acid, filtering and roasting to obtain the modified mordenite catalyst. The modified mordenite catalyst has high catalytic activity for catalytic nitration of aromatic hydrocarbons, high product yield, reusability and long service life.

This invention discloses a highly efficient synthesis method for the low-byproduct polymerization inhibitor DNBP, belonging to the field of polymerization inhibitor synthesis technology. The method first prepares PVP-PS / [BMIM]NO3 composite microspheres, then disperses o-sec-butylphenol and the composite microspheres in ethyl acetate, adds 40%~45% nitric acid (molar ratio 1:2.0~2.2), and reacts at 40℃ and 500~700 r / min for 5 h. After post-treatment and crystallization, the product is obtained. The composite microspheres achieve a synergistic effect through PS core thermal conduction temperature control, PVP shell directional enrichment, and [BMIM]NO3 regulating nitric acid release. This solves the problems of high byproducts and low nitric acid utilization in traditional processes, meeting the requirements of clean production.

The present invention relates to a process for the preparation of α-methyl-[4-(nitro)-2-(trifluoromethyl)]-benzyl nitrate and to the α-methyl-[4-(nitro)-2-(trifluoromethyl)]-benzyl nitrate.

A process and a system to produce sustainable, especially renewable diisocyanates as well as downstream products 5 thereof are provided.

The invention discloses a metalloporphyrin catalyst, a graphene immobilized metalloporphyrin catalyst and a preparation method and application thereof, and belongs to the technical field of applied chemistry and biomimetic catalysis. The invention aims to solve the problems of low efficiency, need of additional ligands, easiness in dimerization, difficulty in recovery and the like of existing metalloporphyrin catalytic oxidation of amino into nitro. The invention provides an imidazole modified metalloporphyrin structure, which is immobilized by using graphene and is applied to oxidation of 4-bromo-2, 6-difluoroaniline. A green and efficient 5-bromine-1, 3-difluoro-2-nitrobenzene synthesis system with a recyclable catalyst is established, 4-bromine-2, 6-difluoroaniline is taken as a raw material, hydrogen peroxide or tert-butyl hydroperoxide is taken as an oxidizing agent, newly synthesized metalloporphyrin is taken as the catalyst, and the 24-hour yield at the room temperature is 69.12% and is increased by 2.3 times compared with the yield of a porphyrin catalyst before modification; wherein the amino-substituted porphyrin still retains considerable activity after being immobilized by graphene, and the activity is retained by 90% or more after the amino-substituted porphyrin is repeatedly used for three times.

The research aims to optimize the synthesis process of oxyfluorfen, improve the product yield and purity, and turn byproducts into wealth. According to an original process route, resorcinol is used as a starting raw material, and oxyfluorfen is synthesized through double etherification, nitration and ether exchange. After optimization, the total yield reaches 94.1%, and the purity reaches 98.4%. In order to improve the utilization rate of the raw materials, an acidic water phase obtained after quenching of an oxyfluorfen reaction solution is subjected to reduced pressure distillation, the byproduct 3-chloro-4-hydroxy-trifluorotoluene is recovered, and the yield can reach 93.7%. Further serving as a raw material of a new process, and synthesizing a target product through nucleophilic substitution. In the route, 2, 4-dichloronitrobenzene with moderate reaction activity and better selectivity is innovatively used for replacing 2, 4-difluoronitrobenzene, so that side reaction is effectively inhibited, and a target product with the content of 98.7% is obtained at the total yield of 94.8%. According to the new and old combination strategy, through integration of two process routes, high-valued conversion of by-products is realized, limitation of a traditional synthesis method is broken through, and atom economy is remarkably improved.

The application discloses a preparation method of nitrophenol, which comprises the following steps: taking a nitrous acid compound as a nitro source, and reacting the nitrous acid compound with a phenol compound in a solvent under the catalysis of an acyl chloride or an anhydride catalyst to generate the nitrophenol. The application has the advantages of wide application range of substrates, mild reaction condition, short reaction time, simple operation, no use of strong acid and metal catalyst, environmental friendliness, excellent yield, and the like, and the yield can reach 95%.

The invention relates to a synthetic method of nitrobenzene, which comprises the following steps: under adiabatic conditions, introducing a first stream of mixed acid and benzene into the first stage of a multi-stage stirring reactor for nitration reaction, then introducing a second stream of mixed acid into the second stage to the Nth stage in batches for continuous nitration reaction, and separating nitration reaction liquid to obtain nitrobenzene, wherein the number of stages of the multi-stage stirring reactor is M, N is larger than 2 and smaller than M, the first mixed acid is obtained by mixing a first sulfuric acid, a nitric acid and a tetravalent cerium compound at the temperature of 50-60 DEG C, the mass fraction of the nitric acid is 0.5%-1.5%, the mass fraction of the sulfuric acid is 65%-68%, the second mixed acid is obtained by mixing a second sulfuric acid, a nitric acid and a tetravalent cerium compound, and the mass fraction of the second sulfuric acid is 0.5%-1.5%. The temperature of the second stream of sulfuric acid is lower than that of the first stream of sulfuric acid, the mass fraction of the nitric acid is 3.0%-5.0%, the mass fraction of the sulfuric acid is 65%-68%, and meanwhile, the molar ratio of the nitric acid in the first stream of mixed acid to the nitric acid in the second stream of mixed acid is controlled to be 2: 98-15: 85, so that the content of nitrophenol compounds can be effectively reduced.

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 provides a nitration device and a nitration process of methyl benzoic acid, the nitration device comprises a first spiral reactor, a static tubular mixer and a second spiral reactor which are communicated with one another, a lower discharge port of the second spiral reactor is communicated with a reaction slurry inlet of the first spiral reactor through a circulation pipeline; when the nitration device provided by the invention is used for nitration of methyl benzoic acid, nitration reaction liquid flowing out of the lower discharge hole of the second spiral reactor is pumped into the first spiral reactor through the circulating pump to form forced circulation, and methyl benzoic acid solid powder added by the spiral feeder is quickly dispersed by the circulating nitration reaction liquid; the blockage is avoided, the mass and heat transfer efficiency is improved, the generation of byproducts is reduced, and the continuous, safe and stable production is ensured.

The invention discloses a method for preparing nitroisopropylbenzene through a micro-channel nitration reaction. The method comprises the following steps: diluting isopropylbenzene with an organic solvent to obtain a mixed solution with the mass concentration of isopropylbenzene being 25-38%, respectively conveying the mixed solution and fuming nitric acid as reaction materials into a microchannel reactor through a metering pump, carrying out a mixed reaction, and completing a nitration reaction to prepare the nitroisopropylbenzene. The method is easy and convenient to operate and high in safety, efficient and continuous production can be achieved, only fuming nitric acid is adopted, nitric acid / concentrated sulfuric acid is not needed, generation of waste acid is reduced, the selectivity of the product is obviously improved, the total yield of nitroisopropylbenzene is 87.7%-95%, and the method has the industrial application advantages of being environmentally friendly and economical.