38 results about "Phosgene" patented technology

The application discloses a continuous synthesis method of an amicarbazone intermediate 5-isopropyl-1,3,4-oxadiazole-2(3H)-ketone. The method comprises two continuous processes of hydrazinolysis and phosgenation: continuously feeding a mixture of isobutyric acid and a solvent, a mixture of hydrazine hydrate and a catalyst into a hydrazinolysis continuous reactor respectively, carrying out a warming reflux dehydration reaction, and obtaining an isobutyryl hydrazine solution shown in formula I; continuously feeding the isobutyryl hydrazine solution and phosgene into a phosgenation continuous reactor, carrying out a phosgenation reaction, and after distillation and desolventizing treatment of a reaction solution, obtaining 5-isopropyl-1,3,4-oxadiazole-2(3H)-ketone shown in formula II. The application has the advantages of simple reaction flow, high product yield, and significant production efficiency improvement, and is suitable for industrial large-scale production.

The present application relates to a kind of equipment and method for preparing hexamethylene diisocyanate by hexamethylene diaminoformate intermediate pyrolysis, the present application uses continuous pyrolysis reaction device, HDI can be prepared in high-boiling solvent, can completely replace the existing phosgene and phosgene derivative method for preparing HDI, solve the safety and pollution problem of phosgene method;Compared with low-boiling solvent process, the present application can greatly reduce energy consumption in product separation stage, and the energy consumption required for separating solvent in high-boiling solvent method is 1 / 10 of low-boiling solvent process, it is a green environmental protection energy-saving process;The present application uses non-toxic high-boiling solvent, compared with low-boiling solvent method, production safety is guaranteed;Compared with ordinary high-boiling solvent, the present application can avoid multiple contact between isocyanate and alcohol, and the yield of HDI can be further improved;The process flow of the present application is simple, and the operating condition is mild, it is a process that can be rapidly industrialized.

The application relates to the technical field of organic synthesis, and discloses a synthesis method of benzthiazuron, which comprises the following steps: step 1, addition reaction of alpha-methyl styrene and hydrogen chloride gas, and degassing to obtain a first reaction liquid; step 2, substitution reaction of the first reaction liquid and cyanate in the presence of a zinc chloride catalyst, and filtration to obtain a second reaction liquid containing isocyanate; and step 3, construction of an inorganic salt aqueous solution system with a density of 1.05-1.10 g / ml and a pH of 9-10, dropwise addition of the second reaction liquid into the system for condensation reaction with o-chlorobenzylamine, and post-treatment and refinement to obtain a target product. The non-phosgene route of chloro-isocyanate substitution is adopted, and the use of the toxic phosgene is completely avoided; the salting-out effect and interface control generated by the specific high-density salt solution effectively inhibit the isocyanate hydrolysis side reaction, and the reaction yield and product purity are obviously improved.

The present invention relates to a method for preparing 2,4-disubstituted thiophene-3-sulfonyl isocyanate compounds having formula (I), wherein the method comprises reacting a compound having formula (II) with phosgene in the presence of a catalyst and a mixture of a nonpolar solvent and an organosulfur cosolvent, and optionally in the presence of a base.

The invention relates to a novel method of producing 4,4'-methylene diphenyl diisocyanate (MDI). A phosgene-free method of producing 4,4'-methylene diphenyl diisocyanate is characterized in that diphenylurea is produced from urea and aniline in an aromatic hydrocarbon medium, and the resulting diphenylurea is reacted with an excess of methanol to produce O-methyl-N-phenyl carbamate; molten O-methyl-N-phenyl carbamate is reacted with anhydrous derivatives of formaldehyde in the presence of acidic catalysts to produce 4,4'-methylene diphenyl dicarbamate; 4,4'-methylene diphenyl dicarbamate in the form of a melt, or of a suspension in an inert carrier liquid, or of a powder is subjected to continuous thermal decomposition in a stream of inert gas, and 4,4'-methylene diphenyl diisocyanate is isolated by fractionation. The invention provides a novel phosgene-free method of synthesizing 4,4'-MDI, which is suitable for industrial-scale implementation.

This utility model relates to the field of chemical equipment technology, specifically a phosgene recovery device. It includes a buffer tank equipped with a spray device and a gas dispersion plate. The top of the buffer tank has a chlorobenzene inlet and a gas outlet, and the bottom has a liquid outlet. A gas inlet is located at the connection point of the gas dispersion plate on the side wall of the buffer tank. The chlorobenzene inlet of the buffer tank is connected to a solvent replenishment tank. The gas outlet and liquid outlet of the buffer tank are respectively connected to the inlet of a falling film absorption tower. The liquid outlet of the falling film absorption tower is connected to the liquid inlet of a receiving vessel, and the gas outlet of the falling film absorption tower is connected to the gas inlet of the receiving vessel. The liquid inlet of the receiving vessel is also connected to a chlorobenzene storage tank. The liquid outlet of the receiving vessel is connected to the solvent replenishment tank, the falling film absorption tower, and the reaction vessel. This utility model can recover and reuse excess phosgene used in production, achieving energy conservation and emission reduction.

This invention relates to "an efficient and safe method for synthesizing perfluoropentanone," belonging to the field of organic chemical synthesis. The method for synthesizing perfluoropentanone is characterized by the following steps: under the action of hexafluoropropylene CF2=CF-CF3, fluorophosgene CF2O, and trifluorobromomethane CF3Br, perfluoropentanone (C5F) is generated in the gas phase. 10 O. The raw materials of this invention are inexpensive and readily available; the product separation and purification are simple; it is easy to industrialize; and it produces less industrial waste.

There are provided a method of producing a carbonyl compound by a flow type reaction, including introducing a triphosgene solution into a flow channel (I), bringing the triphosgene solution into contact with a solid catalyst immobilized in at least a part of the flow channel (I) to generate a phosgene solution while the triphosgene solution is flowing through the flow channel (I), joining the phosgene solution and an active hydrogen-containing compound solution that flows inside the flow channel (II), which are subsequently allowed to flow downstream inside a reaction flow channel to be reacted in a presence of a tertiary amine, and obtaining a carbonyl compound in a joining solution; and a flow type reaction system that is suitable for carrying out this production method.

The application relates to a thermal phosgene reactor and a preparation method of isocyanate, the thermal phosgene reactor comprising a reaction tower, a sieve plate and a pressurizing device, the sieve plate is installed in the reaction tower to divide the space in the tower into upper and lower parts, the sieve plate is located between a feeding port and a discharging port, the sieve plate comprises a plate body, the plate body is provided with through holes and flow channels, the through holes are arranged in a plurality of and penetrate the plate body in the up-down direction, the side wall of the through hole is provided with a gas outlet connected with the flow channel, and the plate body is provided with a gas inlet for allowing external airflow to enter the flow channel; the pressurizing device is arranged outside the reaction tower, and the exhaust port is communicated with the gas inlet of the sieve plate through the pressurizing device, so that the gas discharged at the exhaust port is pressurized and then introduced into the flow channel, the reaction of amine hydrochloride and unreacted free amine in the solid particle material with phosgene is accelerated, the generation of by-product urea is reduced, the product quality is improved, the probability of the occurrence of the plugging condition is reduced, and the operation stability of the device is enhanced.

The application provides a preparation method of 4,6-dichloropyrimidine, which uses 4,6-dihydroxypyrimidine as a starting reaction raw material, halogenated alkane or nitrobenzene as a solvent, triphosgene as a chlorinating reagent, and an organic phosphine as a catalyst, and a morpholine derivative is selected as a cocatalyst. The catalyst and the cocatalyst can be used repeatedly, an acid binding agent is not required in the reaction process, the reaction time is about 3 hours, the product yield is not less than 95.0%, and the method is an efficient and green and environmental 4,6-dichloropyrimidine preparation method.

This invention relates to the field of organic chemistry, specifically to an improved synthesis process for oxalyl chloride. The provided synthesis process for oxalyl chloride includes the following steps: S1. Adding oxalic acid dihydrate to a reaction vessel and stirring to dissolve; S2. Slowly adding a composite catalyst to the molten liquid from step S1 and stirring until the mixture is homogeneous; S3. Adding triphosgene to the mixture obtained in step S2, while simultaneously introducing nitrogen gas from the bottom of the reaction vessel, and reacting at a temperature between 102 and 108°C for 2-3 hours; S4. Condensing the nitrogen gas overflowing from the reaction vessel in step S3 to obtain crude oxalyl chloride; S5. Releasing the nitrogen gas overflowing from the circulating water condenser after absorption by water and alkali; S6. Purifying the crude oxalyl chloride obtained in step S4 to obtain pure oxalyl chloride. The preparation method of this application is simple, easy to industrialize, and the product yield can reach over 95%, with a product purity of over 99.0%.

This invention provides a green method for preparing malononitrile using a trisubstituted phosphine oxide catalyst. The method includes the following steps: in a solvent, cyanoacetamide and solid phosgene or phosgene react in the presence of the trisubstituted phosphine oxide catalyst; the solvent is then recovered by vacuum distillation, and the residue is distilled under vacuum to obtain malononitrile; the three substituents in the trisubstituted phosphine oxide catalyst are each independently selected from aromatic or alkyl groups, and the three substituents may be the same or different. This invention offers a simple preparation method, uses inexpensive and readily available raw materials, resulting in low cost; the organic solvent and catalyst used are recyclable and reusable, generating no wastewater or solid waste, making it environmentally friendly; the reaction conditions are easy to achieve, and the product yield and purity are high.

The utility model relates to chemical production technology, show a kind of for dimethylaminocarbonyl chloride preparation system, including synthesis kettle, chase light kettle, rectifying kettle, rectifying vacuum pump, light gas synthesis device and dimethylamine buffer tank;Light gas synthesis device connects light gas heater, dimethylamine buffer tank connects dimethylamine heater, light gas heater and dimethylamine heater are connected with synthesis kettle respectively, the liquid outlet of synthesis primary condenser and synthesis secondary condenser connected with synthesis kettle of synthesis kettle, the discharge pipe of synthesis kettle is connected with chase light kettle, and chase light kettle connects chase light condenser, and chase light kettle is connected with rectifying column;Rectifying column bottom is connected with fraction tank, and rectifying column middle part is connected with product tank, and rectifying column top is connected with rectifying primary condenser, and rectifying primary condenser is connected with rectifying secondary condenser, and rectifying primary condenser and rectifying secondary condenser are connected with product tank and fraction tank, and rectifying secondary condenser is connected to rectifying vacuum buffer tank, and rectifying vacuum buffer tank is connected with rectifying vacuum pump.

The present invention relates to a process for producing polyisocyanates by reacting an organic amine with phosgene in an inert solvent, the process comprising: (a) mixing an amine-containing feed stream and a phosgene-containing feed stream in a mixing device, thereby obtaining a reaction mixture; (b) feeding the reaction mixture to a residence device in which the reaction continues, thereby obtaining an intermediate reaction mixture; (c) feeding the intermediate reaction mixture to a reactor in which a crude reaction product and a gas phase are obtained, and (d) subjecting the crude reaction product to a post-treatment to remove phosgene, if still present, and a solvent, in which additional gaseous hydrogen chloride is fed to the reactor of stage (c) such that the additional gaseous hydrogen chloride is contacted with the crude reaction product, and removing excess phosgene and hydrogen chloride from the crude reaction product in the reactor by distillation.

This invention relates to the preparation technology of polycarbonate-polyorganosiloxane copolymers, and provides a polycarbonate-polyorganosiloxane copolymer and its preparation method. Using the method of this invention to prepare polycarbonate-polyorganosiloxane copolymers, polymers with low haze and high conversion rates can be obtained. The preparation method includes the following steps: S1, reacting a polyphenol-containing solution I with a phosgene solution II, proceeding to step S2 when U1 satisfies 1.17≤U1≤1.20; S2, adding a capping agent and a polyorganosiloxane to obtain a reaction solution, and performing a first-stage polycondensation reaction, proceeding to step S3 when U2 satisfies 1.20<U2≤1.25; S3, contacting prepolymer a with a catalyst to perform a second-stage polycondensation reaction to obtain prepolymer b, proceeding to step S4 when U3 satisfies 1.35≤U3≤1.51; S4, adding an alkali metal hydroxide solution to prepolymer b to perform a third-stage polycondensation reaction, reacting until U4 in the obtained reaction product satisfies 1.67≤U4≤1.84.

This invention belongs to the field of polycarbonate preparation technology, specifically relating to a method for preparing and applying polycarbonate feedstock, and the polycarbonate feedstock itself. The polycarbonate produced using this invention via a continuous two-phase interface method achieves a satisfactory conversion rate of diphenols in the initial reaction solution. During the research process, the inventors discovered that using an alkaline solution as the reaction substrate, and continuously introducing diphenol alkaline solution and phosgene into the substrate for a photochemical reaction, can reduce the amount of unreacted BPA in the feedstock without phosgene overflow, thus enabling the production of qualified products in the initial stage of the polycarbonate preparation process.

The present application belongs to the technical field of preparing isocyanate, and particularly relates to a method for preparing isocyanate, comprising: 1) mixing a polyamine solution with a phosgene solution and performing a cold phosgenation reaction, and a gas-liquid-solid three-phase mixture A is generated by the reaction; 2) controlling the process conditions of the cold reaction process in stages: the mixture A is subjected to a first stage reaction, and the cold phosgenation reaction is mainly used, the cold reaction process is 50-99.9%, the hot reaction process is 0-30%, and product B is obtained; then the product B is subjected to a second stage reaction, and a mixture of phosgene and hydrogen chloride is introduced into the system at the same time; in the second stage reaction, the cold reaction process is 90-99.9%, and the hot reaction process is 3-40%; and reaction product C is obtained; 3) introducing the reaction product C into a hot reactor, and the product D obtained by the hot reaction is introduced into a refining system for refining. The method of the present application reduces the loss of L color and the generation of impurities caused by the hot reaction at high temperature, and high-quality isocyanate is obtained.

The invention discloses a synthesis method and application of a revivacin key intermediate compound shown as a formula I. Reacting 2-aminobiphenyl, triphosgene and N-Boc-4-hydroxypiperidine in an alkaline reagent to obtain a compound as shown in a formula II; the compound shown in the formula II is subjected to deprotection in an acid system to obtain the compound shown in the formula I. The total yield of the two-step reaction is 93-97%, the purity is 99.2-99.8%, and the method does not need a noble metal catalyst, and is mild in reaction condition, low in cost and simple and convenient in post-treatment. And carrying out nucleophilic reaction on the compound shown in the formula I to prepare revienacin.

This invention relates to a method for preparing indene diazine compounds and oxadiazine insecticides, belonging to the field of pesticide technology. The structure of the indene diazine compound is shown in Formula II: where R is methyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, or a substituted phenyl group. The indene diazine compound shown in Formula II is used to prepare the oxadiazine insecticide shown in Formula I. This invention avoids the use of high-risk materials such as phosgene, triphosgene, and sodium hydride. After multiple batch verifications, the overall reaction yield is stable and suitable for industrial production.

The object of the present invention is to provide an improved process for the preparation of cariprazine compounds of formula (1): which comprises the step of adding a base to a mixture comprising phosgene or a carbonate derivative and an aminopiperazine compound of formula (3) in salt form: to obtain an isocyanate compound of formula (2): and / or a compound of formula (11):

This invention belongs to the field of polymer materials, specifically relating to a method for preparing polycarbonate using a non-phosgene melt transesterification method, and the resulting polycarbonate. The invention involves mixing bisphenol A and diphenyl carbonate at an optimized molar ratio, followed by a transesterification reaction to obtain oligomers. The oligomers are then subjected to a pre-condensation reaction under optimized temperature and pressure, with the residence time controlled to achieve an ideal intrinsic viscosity window. The prepolymer is then subjected to a first and final condensation reaction sequentially to obtain polycarbonate. This invention, through the coordinated control of temperature, pressure, and feed molar ratio during the pre-condensation stage, stabilizes the intrinsic viscosity of the prepolymer within the ideal window, laying a high-quality feed foundation for subsequent condensation polymerization. This significantly improves the impact strength and performance stability of the product, while effectively reducing diphenyl carbonate loss and controlling the end-hydroxyl content of the product. This provides a complete method for the preparation of high-performance polycarbonate.

The present application relates to the technical field of chemical synthesis, and discloses a preparation method of vinyl ethylene carbonate, which uses a widely-sourced and low-toxicity vinyl carboxylic acid as a starting material, and sequentially undergoes three steps of epoxidation, carbon dioxide cycloaddition and hydroxy aldehyde condensation to obtain the target product under the catalysis of a functionalized polymeric ionic liquid. The method avoids the use of the highly toxic phosgene from the source, effectively avoids the generation of amine salt byproducts, and greatly improves the safety and environmental friendliness of the production process. The present application provides a new and feasible technical path for the large-scale and clean production of vinyl ethylene carbonate, and the preparation process has the advantages of low raw material cost, good controllability, green environmental protection and the like, and shows excellent industrial application potential and good market prospect in the field of high value-added fine chemical industry such as lithium ion battery electrolyte additives.

This application relates to the field of phosgene recycling and absorption technology, and in particular to a Venturi tube, a phosgene recycling and absorption system, and a phosgene recycling and absorption method, to solve the problems of scale buildup and blockage at the throat of venturi tubes in related technologies, which leads to shutdowns for cleaning, resulting in extended process and equipment operating cycles and increased operating costs. A Venturi tube includes: an inlet section, a constriction section, a throat, and a diffuser section connected in sequence, and a solvent injection pipe disposed in the constriction section; wherein, the end of the inlet section is used to introduce a first material flow, the outlet of the solvent injection pipe faces the throat, and the outlet of the solvent injection pipe is in contact with the inner wall of the constriction section, avoiding the material flow channel near the central space of the constriction section.

The application discloses a preparation method of sucralose-6-ethyl ester. The method comprises the following steps: under the action of a supported catalyst, sucrose-6-ethyl ester and hexachlorocyclohexa-2,5-dienone are subjected to selective chlorination reaction in a solvent to generate sucralose-6-ethyl ester. The method has simple process and mild conditions, avoids the use of phosgene and thionyl chloride, greatly simplifies the post-treatment process, reduces energy consumption, and is easy to separate the used supported catalyst and environment-friendly.

This invention discloses a method for synthesizing an intermediate of isopropylpyridine, using 3-bromo-4-isopropylaniline as the starting material, and obtaining 2-bromo-4-chloroisopropylbenzene through deamination and chlorination under the action of nitric acid, triphosgene, and a base; wherein the base is 4-pyrrolylpyridine, 4-dimethylaminopyridine, pyridine, etc. The synthesis method of this invention uses inexpensive and readily available starting materials and reagents, resulting in low production costs. Furthermore, the reaction operation is simple, safe, and exhibits good selectivity with few side reactions. In particular, by optimizing the type of base, a reaction yield of at least 80%, or even 90%, and a product purity of at least 90%, or even 95%, can be obtained, making it suitable for large-scale industrial production.

This invention relates to "a method for synthesizing perfluorohexanone," belonging to the field of organic chemical synthesis. The method for synthesizing perfluorohexanone is characterized by the following steps: Dichlorodifluoroethylene (molecular formula CFCl=CFCl), phosgene (molecular formula CF₂O), and anhydrous hydrogen fluoride (molecular formula HF) react in the gas phase with a catalyst to generate pentafluoropropionyl fluoride (molecular formula CF₃CF₂COF). Then, pentafluoropropionyl fluoride reacts with hexafluoropropylene in the gas phase with a dimerization catalyst to generate perfluorohexanone (molecular formula CF₃CF₂C(O)CF(CF₃)₂). This invention utilizes inexpensive and readily available raw materials; the product separation and purification are simple; it is easy to industrialize; and it generates minimal industrial waste.

A continuous synthesis method and device of triphosgene belong to the technical field of fine chemical production. The continuous synthesis method of triphosgene comprises the following steps: S1, continuously conveying dimethyl carbonate to the lower part of a reactor, and continuously inputting chlorine from the bottom of the reactor; S2, after the dimethyl carbonate and the chlorine are mixed in the reactor, a reaction is initiated by irradiation of an ultraviolet light source with a wavelength of 295-395 nm, to generate molten triphosgene and hydrogen chloride gas; wherein the temperature in the reactor gradually increases from bottom to top, presenting a temperature gradient; S3, the molten triphosgene continuously overflows to a degassing tower to remove residual hydrogen chloride under vacuum, and the molten triphosgene product after degassing enters a flaking section. Through optimization of reaction conditions and equipment design, the application can reduce cost, improve the utilization rate of raw materials, reduce the generation of by-products, while ensuring the safety and efficiency of the reaction, and realize efficient, safe and continuous production of triphosgene.

This invention discloses a method for producing high-purity (1R,2S,5R)-WS-3, comprising the following steps: using a mixture of menthol containing eight stereoisomers or naturally extracted menthol as raw material, and reacting it with diethylamine and phosgene under solvent-free conditions at 55-65°C; using a non-chiral adsorbent to separate six diastereomers of (1R,2S,5R)-WS-3 from the obtained WS-3 mixture, and then using a chiral adsorbent to separate the remaining two enantiomers, thus obtaining high-purity (1R,2S,5R)-WS-3. This invention achieves the production of high optical purity (1R,2S,5R)-WS-3 menthol amide cooling agent under mild operating conditions, and has significant industrial application value for the efficient production and quality upgrading of cooling agents.

A process of separating phosgene and hydrogen chloride, comprises: conveying a mixed stream containing hydrogen chloride and phosgene into a distillation column; withdrawing from the distillation column a bottom stream containing phosgene; withdrawing a top stream containing hydrogen chloride; compressing at least a portion of the top stream and at least partially condensing the compressed top stream to form a liquid stream, decompressing at least a portion of the liquid stream to form a cooled liquid stream and a cooled gas stream; and recycling the cooled liquid stream to the top of the distillation column as a reflux; the process additionally comprising temporarily introducing an absorbing solvent into the distillation column, in particular during starting-up and / or shutting-down of the process. The process allows for safe operation even when hydrogen chloride production only gradually begins or decreases, without the necessity of storing hydrogen chloride.