1597 results about "Phosgene" patented technology

Disclosed is a polycarbonate composition and process from making same, wherein introduction of a chain terminator and an acyl halide other than phosgene is after at least 25 percent of the hydroxyl groups in the dihydric phenol have been converted to chloroformate groups.

Processes comprising: (a) reacting phosgene and a monohydroxyl aryl compound in the presence of a suitable catalyst to form a diaryl carbonate and a solution comprising an alkali chloride; (b) separating the diaryl carbonate from the solution; (c) adjusting the pH of the solution to a value of less than or equal to 8 to form a pH-adjusted solution; (d) treating the pH-adjusted solution with an adsorbent to form a treated solution; (e) subjecting at least a portion of the treated solution to electrochemical oxidation to form chlorine and an alkali hydroxide solution; and (f) recycling at least a portion of one or both of the chlorine and the alkali hydroxide solution.

The invention discloses a preparation method of hydrogenated xylylene diisocynate. The preparation method of the hydrogenated xylylene diisocynate comprises the following steps: (1) performing salt forming reaction on 1,3-cyclohexanol dimethylamine and concentrated hydrochloric acid in a two-phase reaction solvent to obtain amine salt, wherein the two-phase reaction solvent consists of water and an inert organic solvent insoluble in water ; (2) performing photochemical reaction on the ammonium salt obtained in the step (1) and phosgene in an inert solvent by taking N,N-dimethylformamide or N,N-dimethylacetamide as a catalyst to obtain reaction liquid, and performing aftertreatment on the reaction liquid to obtain the hydrogenated xylylene diisocynate. The preparation method of the hydrogenated xylylene diisocynate has the advantages of complete ammonium salt formation, small grain size of the ammonium salt, low viscosity of the ammonium salt, high space-time conversion rate of photochemical reaction, simple process, low cost and the like.

The invention provides a novel Lesinurad midbody and provides a synthesis process of Lesinurad, which is economic, efficient, safe, environment-friendly and applicable to large-scale industrial production. The invention further provides a method for preparing the conventional Lesinurad midbody and Lesinurad by using the novel Lesinurad midbody. When synthesized from the novel Lesinurad midbody provided by the invention, the Lesinurad has advantages that the price of necessary raw materials is low, the raw materials are easy to obtain, heavy metal and solvents which are harmful to the environment are not used, the midbody and a product can be easily separated and purified, the operation is easy, application of thiophosgene which is high in toxicity and not easy to operate is avoided, and the total reaction yield is approximate to or higher than that in the prior art.

Copolyorganosiloxanecarbonates are prepared by first preparing an oligomeric aromatic polycarbonate, such as an oligomeric bisphenol A polycarbonate, in the presence of a tertiary amine as the only catalyst species; contacting the oligomeric polycarbonate mixture with a polyorganosiloxane bis(aryl)chloroformate, such as the bischloroformate of hydroxy-terminated eugenol polydimethylsiloxane; and introducing phosgene and/or chain termination agent either continuously or in stages. A feature of the process is the presence of dihydroxyaromatic compound in only one charge, at the beginning. The products have excellent physical properties, including transparency.

The present invention relates to an intermediate of pimavanserin and a similar compound thereof, and a preparation method thereof, and a method for preparing pimavanserin and a similar compound thereof. According to the present invention, the raw materials required by the intermediate have characteristics of low price, easy obtaining, easy separation purification and no requirement of post-treatment, the next step reaction can be directly performed through the one-pot method to prepare the pimavanserin and the similar compound thereof, the operation is simple, and the economical, efficient, safe and environmentally friendly synthesis process is provided for the preparation of the pimavanserin and the similar compound thereof; and with the application of the intermediate to prepare the pimavanserin, the high toxicity and the use of the difficultly-operated phosgene can be avoided, and the total yield of the reaction can achieves the level in the prior art even the higher level.

A two-stage process for the preparation of organic isocyanates by reacting primary amines with phosgene in which a) in a first stage, amine and phosgene are reacted in an adiabatically managed reaction, in which the temperature of reaction is restricted to values between 100 and 220° C. by actively adjusting the absolute pressure in the reactor to values between 8 and 50 bar by decompression, and the temperature is held at values between 100 and 220° C. until the stoichiometric conversion of phosgene has reached at least 80%, and then b) in a second stage, the reaction mixture from a) is decompressed to an absolute pressure of 1 to 15 bar and the reaction mixture is reacted further at temperatures between 90 and 240° C., optionally with the introduction of heat.

The invention relates to a method for continuously preparing toluene diisocynate, in particular to a method for preparing coarse toluene diisocynate by a phosgene method. The method comprises the following steps: mixing toluene diamine and DEIP solvent, performing low-temperature photochemical reaction on the mixture and excessive liquid phosgene in a jet reactor, heating and cracking a reaction product in a photochemical reaction tower to further decompose toluene dicarbamic chloride serving as an intermediate product to form the toluene diisocynate, recycling the reclaimed phosgene and the DEIP solvent, and delivering the hydrogen chloride gas serving as a side product to a hydrogen chloride absorption system.

The invention relates to a method for producing phosgene through the reaction of chlorine and carbon monoxide, and in particular to a method that chlorine and carbon monoxide are used to perform an exothermic reaction in a tube reactor in the presence of an activated carbon catalyst and generate phosgene. In the method provided by the invention, after chlorine is mixed with excess carbon monoxidein a mixer M1, then the mixture enters a tubular reactor C1 to react under the action of the activated carbon catalyst and generate phosgene and then passes through a protection reactor C2 to ensure that chlorine reacts completely; and the heat generated by the reaction is led out by a 60 DEG C cooling water system in closed cycle, the generated gaseous phosgene is cooled through W1 condensation and W2 condensation and enters a phosgene gas-liquid separation tank B2, the un-condensed gas enters an exhaust gas absorber K1, and -5 DEG C toluene is used to absorb and recycle phosgene in tail gas.

The invention relates to a method for purifying cyclic solvent in producing TDI, particularly relates to the case that if the abnormal condition that group impurities containing -NCO such as TDI, CI-TDI, m-CBC and the like are carried by the cyclic solvent DEIP occurs in producing toluene diisocynate (TDI) by a heavy solvent phosgene method, the -NCO group impurities react with TDA and phosgene in a photochemical process to lower TDI yield and generate urea and acid amides residual substances to lead to the problem that production is stopped to clean away obstruction due to the blocking of pipelines and device. The invention uses a processing method of reacting PEG or C2H5OH with -NCO group impurities, adopts rectification to separate the generated heavy components from DEIP to obtain pure DEIP at the tower top to return to a storing bank of the cyclic solvent, and the tower bottom obtains the reacted NCO components and original heavy component residual removal system, thus ensuring smooth operation of the device.

The invention relates to a synthetic method of lauric acyl amino acid sodium, particularly to a synthetic method which uses lauric acid and phosgene as raw materials. The synthetic method comprises the following steps: ensuring that the reaction lasts for 1 to 20 hours at a temperature of 60 to 100 DEG C with the effect of organic amide catalyst; obtaining acyl chloride through vacuum distillation after the reaction is finished; dripping lauric acyl chloride obtained according to the phosgene method into amino acids alkaline solution for reaction; controlling and ensuring the pH value to be within the range of 8 to 10, the reaction temperature to be 15 to 20 DEG C, and the reaction time to be 4 to 5 hours; carrying out cooling after the reaction is finished; acidizing the reaction solution to pH 1 to 2 with hydrochloric acid solution; filtering, washing and drying white sediment to obtain lauric acyl amino acid; dissolving the prepared lauric acyl amino acid with alcohol; adding alcohol solution with sodium hydroxide of equal molar amount; and crystallizing, sucking, filtering and drying after cooling to obtain the lauric acyl amino acid sodium. According to the invention, the synthetic method is reasonable in process, high in reaction efficiency and good in product quality; the three wastes are seldom generated; and no residual phosphorus and sulfur are contained in the product. Therefore, the synthetic method can be widely used in the production of high-end surface active agents, and has significant utility value and social and economic benefits.

The invention discloses a mixer and a method for preparing organic isocyanate. The mixer comprises a main feed pipe, two side feed pipes and a discharge pipe, wherein the main feed pipe and the discharge pipe are arranged on the same axis, and the arrangement of the side feed pipes causes the axes of the side feed pipes and the axis of the main feed pipe are in 60-90 degrees; the point of intersection of the main feed pipe, the side feed pipes and the discharge pipe is provided with a mixed chamber, and an ultrasonic generator is arranged outside the mixed chamber; a microchannel is arranged in the main feed pipe; each side feed pipe is provided with a reduced section near the mixed chamber; and the discharge end of the discharge pipe is provided with an expansion pipe. The mixer of the invention has simple structure and favourable micromixing effect. When used for preparing organic isocyanate, the mixer of the invention can realize favourable micromixing of organic primary amine and phosgene, lowers the usage amount of inert organic solvent as well as the excessive degree of phosgene, reduces solid detention and lowers the danger of solid blockage.

The invention discloses a method for preparing dicyclohexyl methane diisocyanate. The method comprises the following steps: a) a diamino diphenylmethane isomer mixture reacts in an organic solvent at a reaction temperature between 90 and 200 DEG C, under the hydrogen pressure between 3.0 and 12.0 MPa and under the action of a catalyst, so as to obtain a diamino dicyclohexyl methane isomer mixture; and b) the diamino dicyclohexyl methane isomer mixture obtained in the step a) and phosgene are heated to 330 to 400 DEG C so as to be gasify respectively and then are sent into a reactor with a mixing device to be mixed and react, have hydrogen chloride and phosgene removed, and are distilled, so as to obtain the dicyclohexyl methane diisocyanate. The method has the advantages of prolonging the life span of the catalyst and reducing cost. The invention also provides a complete technological process for preparing the dicyclohexyl methane diisocyanate.

An object of the present invention is to provide a process that enables isocyanates to be stably produced over a long period of time at high yield without encountering various problems as found in the prior art when producing isocyanates without using phosgene. The present invention discloses a process for producing an isocyanate, comprising the steps of: reacting a carbamic acid ester and an aromatic hydroxy compound to obtain an aryl carbamate having a group derived from the aromatic hydroxy compound; and subjecting the aryl carbamate to a decomposition reaction, wherein the aromatic hydroxy compound is an aromatic hydroxy compound which is represented by the following formula (1) and which has a substituent R¹ at least one ortho position of a hydroxyl group:

(wherein ring A represents an aromatic hydrocarbon ring in a form of a single or multiple rings which may have a substitute and which have 6 to 20 carbon atoms;

• • R¹ represents a group other than a hydrogen atom in a form of an aliphatic alkyl group having 1 to 20 carbon atoms, an aliphatic alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or an aralkyloxy group having 7 to 20 carbon atoms, the group containing an atom selected from a carbon atom, an oxygen atom and a nitrogen atom; and R¹ may bond with A to form a ring structure).

An isocyanate is produced by reacting a primary amine with phosgene in the gas phase above the boiling point of the amine over an average contact time of 0.05 to 15 seconds under adiabatic conditions.

The present invention relates to a process for the production of 4,4′-diphenylmethane diisocyanate (4,4′-MDI) by acid-catalyzed condensation of aniline with formaldehyde, reaction of the mixtures of di- and polyamines obtained with phosgene to form the corresponding mixture of MDI isomers and homologues (di- and polyisocyanates of the diphenylmethane series) and subsequent separation of the mixture by distillation to form 4,4′-MDI and polymeric MDI.