53results about "Urea derivatives preparation" patented technology

This invention discloses a method for improving the yield of urea phosphate in the preparation of wet-process phosphoric acid. The method involves mixing a crystallizer with wet-process phosphoric acid and urea, reacting the mixture, and then cooling, crystallizing, filtering, and drying to obtain urea phosphate. Alternatively, wet-process phosphoric acid is mixed with urea and reacted. After the reaction, a crystallizer or a urea phosphate mother liquor containing the crystallizer is added, followed by cooling, crystallizing, filtering, and drying to obtain urea phosphate. The crystallizer is one or a mixture of two or more of ethylene glycol methyl ether, ethylenediaminetetraacetic acid, and citric acid in any proportion. The urea phosphate produced by this method is in crystalline form, meeting the industrial urea phosphate standard (GB / T27805-2011), satisfying market demand, and featuring a low-cost crystallizer with flexible addition methods, making it very convenient for practical production.

The present application belongs to the technical field of condensate, and particularly relates to a non-peptide small molecule condensate and preparation and application thereof. The present application provides a non-peptide small molecule condensate which is prepared by taking a small molecule shown in formula I as a precursor, wherein Y and Z are each independently NH, O or S, R = or X = O or S; R1 and R2 are each independently selected from H, C 3‑20 alkyl, -C 1‑8 alkylene-phenyl, -C 1‑8 alkylene-5-10-membered heteroaryl, -C 1‑8 alkylene-S-C 1‑8 alkyl, -C 1‑8 alkylene-SH, -C 1‑8 alkylene-O-C 1‑8 alkyl or -C 1‑8 alkylene-NH-C 1‑8 alkyl; and R1 and R2 are not H at the same time. The obtained condensate not only has good spontaneous non-classical fluorescence characteristics, but also has the abilities of drug loading and controllable release, and shows excellent resistance to enzymatic hydrolysis and good biocompatibility. Formula I

The application provides a low-temperature methanol washing and urea generation combined energy-saving system and method, comprising a feed heat exchanger, a cooling separation unit, an absorption tower, a liquid phase treatment unit and a urea synthesis unit, each unit cooperatively realizing process deep integration and energy coupling; the application takes the purified reflux liquid phase CO2 as the cooling source of the cooling separation unit, without external refrigeration, reducing low-temperature methanol washing cooling source consumption, also reducing the absorption tower treatment load, reducing its energy consumption, equipment investment and CO2 emission; the product liquid phase CO2 is directly supplied to the urea synthesis after cold energy recovery through the heat exchanger, replacing the traditional CO2 gas pressurization process, eliminating the secondary energy consumption of transportation. The multi-channel heat exchanger realizes cold energy step-by-step utilization, improving the overall energy efficiency. The application realizes self-provided cold energy and efficient energy recovery, achieves CO2 resource utilization, simplifies the process and reduces the maintenance cost, and the system is economic and environmentally friendly, and is suitable for industrial application of coal chemical industry and chemical fertilizer production.

A process and apparatus for CO2 stripping of urea, wherein urea is formed by reaction of ammonia with carbon dioxide in a vertical reactor (1); a first urea-containing stream (12) is withdrawn from an intermediate height of the reactor by means of a first downcomer (103) and is fed to a high-pressure stripping column (2); a second urea-containing stream (15) is withdrawn from an upper height of the reactor by means of a second downcomer (104) and is fed to an eductor (4) for reintroduction into the reactor together with fresh ammonia.

This invention belongs to the field of pharmaceutical preparation technology, specifically relating to an HDAC inhibitor based on a tyrosine backbone, its synthesis method, and its application. The invention uses L-tyrosine as the backbone, with its aromatic ring as the Cap region, linked by a flexible alkyl chain via an ether bond, and terminated by an isohydroxamic acid group (ZBG). The tyrosine backbone provides a rigid structure, reducing entropy loss and enhancing hydrophobic interactions with the HDAC surface. By introducing substituents (such as halogens, methyl groups, etc.) onto the tyrosine benzene ring, the affinity with the HDAC active pocket is further optimized. The prepared compound b19 exhibits an HDAC inhibition capacity of 100%. 50 The concentration reached 26.8 nM, exhibiting superior antitumor activity compared to SAHA, especially against solid tumors such as HeLa cells with IC50. 50 It is 0.55 μM.

This invention discloses a near-infrared electrochromic material, device, and its preparation method and application based on electron-induced proton transfer, belonging to the field of intelligent optoelectronic materials. The near-infrared electrochromic material includes acid-responsive near-infrared chromophore molecules and electroacid molecules; the electroacid molecules include diarylurea compounds, and the acid-responsive near-infrared chromophore molecules include cyanine acid-responsive near-infrared chromophores. This material combines Cy-N and Urea-N, utilizing the release of protons during the oxidation process of the electroacid to trigger the protonation state transition of the near-infrared chromophore, achieving reversible modulation of near-infrared absorption. The near-infrared electrochromic device exhibits significant near-infrared light modulation capability at 820 nm, with a coloring efficiency of up to 76.13 cm² / C, fast response speed, and good reversibility, maintaining stable performance after more than 1000 cycles.

This invention belongs to the technical field of drug synthesis, specifically relating to memantine derivatives, their synthetic methods, and applications. The memantine derivatives include intermediate structural formulas I, II, and III, as well as a general structural formula. The linker is a substituted or unsubstituted C6-C10 aryl group, R1 is hydrogen or a C1-C6 alkyl group, and R2 is hydrogen, a C1-C6 alkyl group, or a nitrogen-containing or nitrogen-free structural fragment, or the overall structure of R1 and R2 is an N-substituted heterocyclopentyl or heterocyclohexyl group. The memantine derivatives provided by this invention improve drug activity by combining the memantine group with the OAB-14 partial structure, thereby altering the core structure. This invention also provides a synthetic method for the obtained compounds used in the treatment of Alzheimer's disease and Parkinson's disease.

The present invention relates to a new process for the purification of substituted phenylurea derivatives, in particular of 3-(3,4-dichlorophenyl)-1,1-dimethylurea.

System (1) for separating CO2 from a CO2-containing offgas (2) from an industrial plant (3), wherein the system (1) comprises an offgas recirculation circuit (4) connectable to the industrial plant (3), an ammonia synthesis plant (5), an air fractionation plant (6) for fractionating air into oxygen (7) and nitrogen (8), and a fertilizer production plant (9), wherein the offgas recirculation circuit (4) is designed to enrich a first portion (A1) of the offgas (2) with the oxygen (7) and feed it to the industrial plant (3), and to feed a second portion (A2) of the offgas (2) to the fertilizer production plant (9), and wherein the ammonia synthesis plant (5) is designed to synthesize ammonia (11) from the nitrogen (8) and hydrogen (10), and wherein the fertilizer production plant (9) is designed to produce plant fertilizer (12) from the CO2 present in the second portion (A2) of the offgas (2) and the ammonia (11).

The present disclosure relates to a preparation method for L-citrulline, comprising: Step 1 of preparing a fermentation broth comprising L-citrulline; Step 2 of performing a continuous chromatography process on the fermentation broth to obtain a purified citrulline process liquid; and Step 3 of crystallizing and separating L-citrulline in the purified citrulline process liquid. According to the present disclosure, high purity L-citrulline crystals can be obtained in high yield from the fermentation broth.

A total-recycle process for the production of an aqueous urea solution, including: reacting ammonia and carbon dioxide in a urea reactor obtaining a high-pressure urea solution; said solution is expanded and processed to a first recovery pressure; the processing at the first recovery pressure includes decomposition of ammonium carbamate to obtain a partially purified urea solution; said partially purified urea solution is processed to a second recovery pressure of 1.5 bar to 3.0 bar to decompose ammonium carbamate, obtaining a gaseous stream containing ammonia and carbon dioxide and a low-pressure urea solution at a temperature of at least 130 °C; said low-pressure urea solution is adiabatically expanded to atmospheric pressure and introduced in a receiver vessel wherein residual vapours of ammonia and carbon dioxide are released and a final urea solution is produced; said final urea solution has a content of ammonia not greater than 0.2% by weight when the solution is at 31-33% of urea; said process does not include a treatment in a wastewater treatment section.

Provided herein are systems and methods for producing renewable nitrogen products.

The present disclosure is related to a pipe reactor. In its broadest aspect, the present disclosure is related to a method for producing a urea ammonium sulphate-based composition in a pipe reactor comprising a first and a second mixing zone. The method comprises the steps of: a) directing a liquid stream comprising ammonium bisulphate to the first mixing zone of the pipe reactor; b) directing a first stream of ammonia to the first mixing zone of the pipe reactor for reacting with the liquid stream comprising ammonium bisulphate, provided in step a), to obtain a liquid stream comprising ammonium sulphate; c) directing the liquid stream comprising ammonium sulphate, provided in step b), to the second mixing zone of the pipe reactor; and d) directing a liquid stream of urea to the second mixing zone of the pipe reactor for mixing with the liquid stream comprising ammonium sulphate.

This invention discloses a method for synthesizing biphenyl compounds and their derivatives, comprising the following steps: under blue light irradiation and in an inert atmosphere, an aryl halogen compound reacts with a base in solvent A, and then the reaction mixture is separated to obtain the biphenyl compounds and their derivatives. The technical solution of this invention has the following significant advantages: without the need for additional photocatalysts, the synthesis of biphenyl compounds and their derivatives can be achieved solely through photoinduction. Compared with existing technologies, the method for synthesizing biphenyl compounds and their derivatives described in this invention has the following characteristics: wide availability of raw materials, simple operation process, mild reaction conditions, economic efficiency, and environmental friendliness.

The present invention provides a blocking agent dissociation catalyst for a blocked isocyanate, the blocking agent dissociation catalyst containing a zwitterionic compound represented by formula (1). Formula (1): (In the formula, A, R1, R2, X, B1, and a are as defined in the specification.)

The present application relates to the field of catalytic materials, in particular to a cerium lanthanum rare earth-based carbon-nitrogen-oxygen quinary eutectic nanomaterial, a preparation method and application thereof. The cerium lanthanum rare earth-based carbon-nitrogen-oxygen quinary eutectic nanomaterial is an ultrathin flake-shaped amorphous / short-range ordered quinary lattice eutectic structure formed by atom-level eutectic of cerium, lanthanum, carbon, nitrogen and oxygen, has excellent abnormal temperature stability, and has no decay in phase and catalytic activity after being placed at normal temperature and pressure for more than 30 days. The material has a catalytic degradation efficiency of biuret of more than 99%, has low energy consumption in the preparation process and is easy to be scaled up industrially, can be widely applied to the fields of urea solution purification and automobile exhaust SCR system anti-crystallization, and solves the industry bottleneck of difficult degradation of biuret.

The present disclosure provides a pressure control valve, in particular for use in a urea-producing plant. The present disclosure also provides a urea-producing plant comprising one or more pressure control valves, and the use of a pressure control valve in a urea-producing plant.

A urea stripper or evaporator provided with fittings in the bottom liquid holder to reduce gas carryover wherein said fittings may include one or more of: perforated screens horizontally arranged or vertically in the bottom liquid holder; a sealed chamber arranged in the liquid holder to reduce the liquid collection volume in the liquid holder: a plurality of blades and / or vertical plates projecting from the inner surface of a bottom domed end of the apparatus to reduce speed of the liquid flow.

The present application relates to a kind of organic amine catalyst for preparing polyurethane system and its application, the organic amine catalyst for preparing polyurethane system of the present application, with high steric hindrance, with excellent HFO compatibility, high gel selectivity, reactive low emission catalyst.The organic amine catalyst of the present application meets the comprehensive requirements of long-term storage stability, excellent fluidity and mechanical properties for HFO rigid polyurethane foam.

This invention relates to a corrosion-resistant duplex stainless steel (ferritic austenitic alloy) for use in an apparatus for urea production; and its applications. This disclosure also relates to objects made of said duplex stainless steel. Furthermore, this disclosure relates to a method for urea production and an apparatus for urea production comprising one or more components made of said duplex stainless steel, and to a method for modifying an existing apparatus for urea production.

The present application discloses a supported bimetallic-based two-dimensional nanocatalytic material, a preparation method thereof, and an application thereof, which relate to the technical field of catalysts. The preparation method includes: preparing a plasma nanosheet with a single-layer structure or a few-layer structure; dispersing the plasma nanosheet in a solvent and adding a copper source to prepare a first mixed solution; subjecting the first mixed solution to stirring treatment in an inert gas environment, and successively performing freeze-drying treatment and calcination treatment in a hydrogen atmosphere to prepare a nanosheet-Cu; successively adding HAuCl4 and HCl to the nanosheet-Cu, mixing and reacting under a preset light condition to prepare a supported bimetallic-based two-dimensional nanocatalytic material, namely, a nanosheet-Cu-Au. The present application can achieve the functional division and spatial synergy of bimetallic active sites, and promote the efficient generation, separation, and directional transport of photo-generated carriers, thereby improving the reaction efficiency and product selectivity of the co-reduction of nitrate and carbon dioxide to urea.

A cooling device comprising a housing configured by means of size and shape to contain an object to be cooled; and either one or more chambers comprising either solid urea or a urea / solvent mixture, or one or more reservoirs containing a urea / solvent mixture. The chamber(s) are fillable with water via a sealable opening and are in thermal communication with the exterior of the cooling device, with water being addable to the chamber(s) when the cooling device is used. The reservoir(s) contain a urea / solvent mixture and are reservoir fluidly connectable to one or more chambers. The chamber(s) are fillable with water via a sealable opening and are in thermal communication with the exterior of the cooling device.

The application belongs to the field of macrolide polymerization, and relates to a diurea compound with an alicyclic structure, a preparation method, a catalyst system and a polymerization method. The structural formula of the diurea compound is as follows: in the formula, R is an alicyclic structure unit with C6-C18, R1 and R2 are each independently selected from at least one of a hydrogen atom, a C1-C20 alkyl group, a C3-C20 cycloalkyl group, a C6-C20 aromatic group and a substituted C6-C20 aromatic group. The application first proposes that a metal-free organic base / diurea catalyst system can be used to open ring polymerize macrolide polymerization and copolymerize macrolide and other cyclic monomers. The catalyst is easy to synthesize, low in cost, free of metal ions, low in polymerization temperature of the system, and mild in polymerization conditions, and can be used for polyhydroxyl prepolymers or block copolyesters of polyurethane, and has wide application and research value.

The present invention relates to a vinylarene deriv. which modulates or inhibits the enzymic activity of indoleamine 2,3-dioxygenase 1 (IDO-1), and the use thereof, and further relates to a vinylarene deriv. and the use thereof. The vinylarene deriv. and its stereoisomer, cis- or trans-isomer, or tautomer thereof and pharmaceutically acceptable salt thereof, has an IDO-1 enzyme inhibitory activity, and is expected to provide brand new therapeutic methods and schemes for related diseases caused by IDO enzymes.

The patent discloses an oxygen vacancy modified Bi2O3 / Bi2O4 heterojunction and a preparation method and application thereof. The preparation method comprises the following steps: firstly, a Bi2O3 / Bi2O4 heterojunction is prepared by a one-step hydrothermal method with NaBiO3 as a precursor and under the condition of reaction at 160 DEG C for 12 hours; the heterojunction is subjected to ultrasonic treatment in an H2O2 aqueous solution, and then washed and dehydrated at 60 DEG C for 12 hours, so that an oxygen vacancy modified Ov-Bi2O3 / Bi2O4 material is finally obtained. The heterojunction is composed of cubic phase Bi2O3 and monoclinic phase Bi2O4, the introduction of oxygen vacancies effectively optimizes the energy band structure of the material while maintaining the integrity of the crystal structure, and improves the separation efficiency and mobility of photo-generated carriers. Under the irradiation of simulated sunlight, the optimized catalyst realizes a urea yield of up to 356.1 μg·L ‑1 within 4 hours, and exhibits excellent photocatalytic C-N coupling performance.

The application discloses givinostat and a synthesis method thereof, wherein compound 1 is used for synthesizing compound 2 in step 01; compound 3 is used for synthesizing compound 4 in step 02; compound 4 is used for synthesizing compound 5 in step 03; compound 5 is used for synthesizing compound 6 in step 04; and compound 6 and compound 2 are used for synthesizing givinostat in step 05. After optimization, the yield of compound 1 to compound 2 reaches more than 80 %, raw materials and reagents used in the reaction are cheap and easy to obtain, and the preparation cost is very low; only four steps are needed from compound 3 to the target product, the route is short, and the operation is simple; and after optimization, the total yield of compound 3 to the target product reaches more than 40 %, the yield is high, and the preparation cost is significantly reduced.

The application discloses a preparation method of a No. 2 medium setting agent, and is characterized in that the No. 2 medium setting agent is prepared according to the following steps: (1) N-methylaniline, NaOH and water are added into a reaction kettle, and a stirrer is started to mix, and the mixture is layered, and the upper layer is an N-methylaniline layer, and the lower layer is an NaOH aqueous solution layer; (2) an acylation reagent is introduced into the reaction kettle through an insertion pipe, the bottom end of the insertion pipe is located in the upper N-methylaniline layer, the stirring speed is controlled to be 50-300 r / min, and a product is obtained through stirring reaction. According to the application, the side reaction of acyl chloride hydrolysis is greatly inhibited by controlling the reaction temperature, the acylation reagent feeding height and the stirring speed, the generation of salt-containing wastewater is reduced, the environmental protection pressure is reduced, and the selectivity of the No. 2 medium setting agent is improved.