152results about "Preparation by dehalogenation" patented technology

The invention provides chlorotrifluoroethylene continuously prepared based on a microchannel reactor and a preparation method of the chlorotrifluoroethylene, and the chlorotrifluoroethylene comprises the following raw materials in parts by weight: 1, 1, 2-trifluoro-1, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 The low-temperature refrigerant refrigerant is prepared from the following components in parts by weight: 90 to 100 parts of 1, 2-trichloroethane, 1 to 5 parts of a zinc fluoride induced palladium-copper bimetallic catalyst, 8 to 15 parts of a cyclohexyl dimethyl ether-formic acid composite hydrogen donor, 0.5 to 2 parts of trifluoroacetic anhydride, 0.1 to 0.5 part of a perfluoropolyether lubricant, a proper amount of a low-temperature mixed refrigerant and 15 to 20 percent by weight of diluted hydrochloric acid. According to the invention, the preparation efficiency and product purity of chlorotrifluoroethylene can be improved, and stable operation of the preparation system and reasonable treatment of byproducts can be guaranteed.

The invention provides a reactor comprising a reaction chamber having a catalytic surface in contact with reactants in said chamber; and a source for passing electrical current through said catalytic surface. The reactor can be used for dehydrohalogentation reactions, such as dehydrochlorination of HCFC-244bb to HFO-1234yf, and for reactions where zero valent metals are employed for catalysis. The invention further provides a process to prepare HFO-1234yf from HCFC-244bb using an electrically heated reaction chamber.

The production of HFO-1132, and in particular HFO-1132 E, may be produced from 1, 1, 2-trichloro-1, 2, 2-trifluoroethane (CFC-113), and the production of HFO-1132, and in particular HFO-1132 E, may be produced from 1, 1, 2-trichloro-1, 2, 2- In a first step, 1, 1, 2-trifluoroethane (HFC-143) is produced by hydrogenating 1, 1, 2-trichloro-1, 2, 2-trifluoroethane (CFC-113) by reacting with hydrogen in the presence of a catalyst to produce 1, 1, 2-trifluoroethane (HFC-143). The 1, 1, 2-trifluoroethane (HFC-143) may then be dehydrofluorinated in the presence of a catalyst to produce trans-1, 2-difluoroethylene (HFO-1132E) and / or cis-1, 2-difluoroethylene (HFO-1132Z). The cis-1, 2-difluoroethylene (HFO-1132Z) may then be isomerized to produce the trans-1, 2-difluoroethylene (HFO-1132E), and then the cis-1, 2-difluoroethylene (HFO-1132Z) may be isomerized to produce the cis-1, 2

The application relates to the field of organic synthetic chemistry, in particular to a diamino diphosphine tetradentate ligand, a preparation method thereof and application of the diamino diphosphine tetradentate ligand in Suzuki cross-coupling reaction. The diamino diphosphine tetradentate ligand provided by the application has a structure shown in formula I; due to special spatial structure and electronic properties, the diamino diphosphine tetradentate ligand can provide multi-point coordination to metal and form a stable complex with the metal, so that the activity and stability of a palladium catalyst can be improved, the palladium catalyst can efficiently catalyze the Suzuki cross-coupling reaction for constructing a C-C bond at an extremely low dosage, and the diamino diphosphine tetradentate ligand and the metal palladium catalyst have strong universality to Suzuki cross-coupling reaction substrates, and have wide potential application value.

The invention relates to a method for preparing an aryl compound by taking ethanol as a green reducing agent and a solvent. According to the method, under the condition of a palladium catalyst, fluoro-aromatic hydrocarbon is mixed with alkali and alcohol to be subjected to a defluorination hydrogenation reaction, and the alcohol comprises ethanol and / or isobutanol. In the reaction, ethanol and / or isobutanol serve as a solvent and a reducing agent at the same time, no extra reducing agent needs to be added, and use of dangerous reducing agents such as hydrogen and lithium aluminum hydride is avoided. The catalyst system is excellent in substrate applicability and can be well compatible with common electron donating groups, electron withdrawing groups and heterocyclic rings, and the highest yield can reach 99%. In addition, the reaction system can be carried out in analytically pure ethanol and air, complicated anaerobic operation is not needed, and large-scale industrial application is facilitated.

An azeotrope or azeotrope-like composition consists essentially of an effective amount of 1-chloro-1, 1-difluoroethane (HCFC-142b) and 1, 1, 2-trifluoroethane (HFC-143), and a method for producing the azeotrope or azeotrope-like composition. Also disclosed are methods for separating azeotrope or azeotrope-like compositions and / or utilizing the same in extraction and pressure swing distillation in conjunction with methods of making 1, 1, 2-trifluoroethane (HFC-143).

The invention discloses a preparation process of an R-1234yf refrigerant based on a heterogeneous catalyst, and relates to the field of preparation of refrigerants. According to the method, tetrafluoroethylene and trichloromonofluoromethane are subjected to a reaction through a liquid phase reaction to generate an intermediate product CCl3CF2CF3 (CFC-215cb), then the CFC-215cb is subjected to a catalytic hydrodechlorination reaction to obtain CH3CF2CF3, and then the CH3CF2CF3 is subjected to a catalytic elimination reaction to generate the target product R-1234yf. According to the method, the self-developed catalyst is used as a liquid phase reaction catalyst, Pd / Pd-AlF3 is used as a hydrogenation catalyst, and AlF3, Cr2O3 or activated carbon is used as an elimination catalyst, so that efficient and environment-friendly R-1234yf preparation is realized under mild conditions, and the method has the advantages of high reaction selectivity, high yield and few byproducts.

A method of synthesizing 3,3,3-trifluoropropene including contacting 1,1,1,3-tetrachloropropane, in the vapor phase, at a temperature sufficient to effect dehydrochlorination to form 1,1,3-trichloro-1-propene. The 1,1,3-trichloro-1-propene is isolated and subsequently contacted, in the vapor phase, with hydrogen fluoride in the presence of a fluorination catalyst at a temperature sufficient to effect formation of 3,3,3-trifluoropropene.

The application discloses a synthesis method of monofluoro olefin compound and belongs to the technical field of organic synthesis. 3 )‑F bond and C(sp 2 )‑F bond are broken to obtain a trisubstituted (E) monofluoro olefin compound 3; when the olefin substrate is gem-di-fluoro olefin 4, a di / trisubstituted (E) monofluoro olefin compound 5 is also obtained at a high yield and excellent stereoselectivity. The synthesis method has the advantages of cheap catalyst, simple and easily-obtained raw materials and good substrate applicability, and the synthesized product is a very valuable fluorinated component, and a new method is provided for modification of fluorine-containing molecules.

The present invention relates to a process for producing trifluoroethylene in a reactor provided with a fixed catalytic bed comprising a catalyst, said process comprising a step a) of reacting a composition A comprising chlorotrifluoroethylene with hydrogen in the presence of a catalyst and in the gas phase to produce a stream B comprising trifluoroethylene, characterized in that said composition A also comprises at least one of the additional compounds C1 chosen from the group consisting of 1,1,1-trifluoroethane, 1,1,1,2-tetrafluoroethane, hexafluorocyclobutene, fluoroethane, 2-chloro-1,1,1-trifluoroethane, 1,2-dichlorohexafluorocyclobutane. The present invention also relates to a chlorotrifluoroethylene composition.

Provided is a method for producing a fluoroethane compound with which it is possible to efficiently produce a fluoroethane compound that is a target product. Comprising a step (A) in which the chlorofluoroethane compound according to the present invention is subjected to a reduction reaction in the presence of a catalyst in which at least one metal selected from the group consisting of Ni, Pd, Pt, Ru and Rh is supported on activated carbon to produce a product containing a fluoroethane compound. With this production method, a fluoroethane compound, which is a target product, can be efficiently produced.

The invention provides a synthesis method of 1, 5-dibromo-3-fluoro-2, 4-xylene, and belongs to the field of synthesis of fine chemical intermediates. According to the method, 2-fluorine-m-xylene is taken as a starting raw material, and 1, 5-dibromo-3-fluoro-2, 4-xylene is obtained through two steps of bromination and reduction. According to the synthesis method, the problem that accurate bromination positioning cannot be realized is solved by optimizing reaction raw materials and operation steps, so that the purity and yield of the product are greatly improved. The synthesis method is simple and stable, and has great industrial production value.

This application provides a method for preparing hexafluorobutadiene, belonging to the field of hexafluorobutadiene manufacturing technology. The method includes the following steps: reacting 1,4-dibromooctafluorobutane, a catalyst solution, and zinc powder under heating conditions and collecting the generated gaseous hexafluorobutadiene; wherein the catalyst solution contains N,N-dimethylformamide, and the reaction temperature is lower than the boiling point of the catalyst solution with a difference of 5℃~40℃; this preparation method can produce hexafluorobutadiene in a one-step reaction using only an industrial-grade catalyst, and has the advantages of simple process steps, low energy consumption, simple catalyst system, low cost, and good safety.

To produce a hydrogenated alkene by way of hydrogen substitution.SOLUTION: An alkene production method includes a step in which a hydrogenation reaction is performed in the presence of an activated carbon catalyst supporting a precious metal or a noble metal.SELECTED DRAWING: None

The application discloses a preparation method of hexafluorobutadiene and belongs to the technical field of hexafluorobutadiene preparation. The preparation method of hexafluorobutadiene comprises the following steps: (1) subjecting trifluorobromoethylene to thermal polymerization reaction under the action of a catalyst to obtain a mixture of 1,2-dibromohexafluorocyclobutane, 3,4-dibromo-hexafluoro-1-butene and hexafluorobutadiene; (2) separating the mixture of step (1) through condensation and rectification to obtain hexafluorobutadiene and 3,4-dibromo-hexafluoro-1-butene respectively; and (3) obtaining hexafluorobutadiene through dehalogenation reaction of 3,4-dibromo-hexafluoro-1-butene. The preparation method of hexafluorobutadiene can realize simple reaction process, low danger and preparation of hexafluorobutadiene with high yield under relatively mild conditions; and the yield of the obtained hexafluorobutadiene reaches 61% or above.

The present invention provides a method for preparing a supported carbon catalyst, the method comprises at least the following steps: (1) contacting a gas containing an organic silicon source with a silicon oxide-based material to obtain a precursor; (2) contacting the precursor with a gas containing an organic carbon source to obtain the supported carbon catalyst. The temperature and energy consumption of the chemical vapor deposition of heteroatom-containing carbon material on silica-based materials can be greatly reduced in this method, and the cost of the catalyst can be effectively reduced.

The present invention relates to a process for producing trifluoroethylene in a reactor equipped with a fixed catalytic bed comprising a catalyst, said process comprising a step a) of reacting a composition A comprising chlorotrifluoroethylene with hydrogen in the presence of a catalyst and in the gas phase in order to produce a stream B comprising trifluoroethylene, characterized in that said composition A also comprises at least one of the additional compounds C1 chosen from the group consisting of 1,1,1-trifluoroethane, 1,1,1,2-tetrafluoroethane, hexafluorocyclobutene, fluoroethane, 2-chloro-1,1,1-trifluoroethane and 1,2-dichlorohexafluorocyclobutane. The present invention also relates to a chlorotrifluoroethylene composition.

The present invention relates, in part, to the discovery that the presence of HF in a HCFC-244bb feedstream in a reaction for the preparation of HFO-1234yf results in selectivity changeover from HFO-1234yf to HCFO-1233xf. By substantially removing HF, it is shown that the selectivity to HFO-1234yf via dehydrochlorination of HCFC-244bb is improved.

In some embodiments, HFO-132, and in particular HFO-1132E, may be produced from 1, 1, 2-trichloro-1, 2, 2-trifluoroethane (CFC-113), and in particular HFO-1132E may be produced from 1, 1, 2-trichloro-1, 2, 2-trifluoroethane (CFC-113). In a first step, 1, 1, 2-trifluoroethane (HFC-143) is produced by hydrogenating 1, 1, 2-trichloro-1, 2, 2-trifluoroethane (CFC-113) by reacting with hydrogen in the presence of a catalyst to produce 1, 1, 2-trifluoroethane (HFC-143). The highly exothermic hydrogenation step may be moderated by diluting the catalyst and / or by diluting the 1, 1, 2-trichloro-1, 2, 2-trifluoroethane (CFC-113) feedstock. The 1, 1, 2-trifluoroethane (HFC-143) may then be dehydrofluorinated in the presence of a catalyst to produce trans-1, 2-difluoroethylene (HFO-1132E) and / or cis-1, 2-difluoroethylene (HFO-1132Z). The cis-1, 2-difluoroethylene (HFO-1132Z) may then be isomerized to produce a trans-1, 2-difluoroethylene (HFO-1132E), and then, the cis-1, 2-difluoroethylene (HFO-1132E) may be isomerized.

Alkenyl halides, such as alkenyl bromides or alkenyl chlorides, are produced by a process comprising the steps of forming a reaction mixture containing alkyl dibromides or chlorobromoalkanes and allylmagnesium bromide and / or allylmagnesium chloride, and then producing the alkenyl halides in the reaction mixture.

The invention provides a regeneration method and application of a chromium fluoride-based catalyst, and relates to the technical field of fluorine-containing olefin preparation. The regeneration method of the chromium fluoride-based catalyst comprises the following steps: A1, forcibly inactivating or collecting the inactivated chromium fluoride-based catalyst in industrial production; a2, a step of oxidizing and decarbonizing the inactivated chromium fluoride-based catalyst; and A3, treating the oxidized chromium fluoride-based catalyst in mixed gas of carbon monoxide and inert gas. The regenerated chromium fluoride-based catalyst can be used for reactions such as preparation of trans-1-chloro-3, 3, 3-trifluoropropene from 1, 1, 1, 3, 3-pentachloropropane, preparation of 2-chloro-3, 3, 3-trifluoropropene from 1, 1, 1, 2, 3-pentachloropropane and the like, and the selectivity of a target product is obviously improved.

The invention discloses a quaternary ammonium salt PCR (Polymerase Chain Reaction) hot start reagent as well as a preparation method and application thereof, the chemical name of the PCR hot start reagent is 5 ', 5' '-bis (4-bromophenyl)-2', 2 '', 4 ', 4' ', 6', 6 ''-hexamethyl-1, 1 ': 3', 1 ': 3', 1 '''quaternary ammonium salt, and the PCR hot start reagent is a compound formed by removing two bromine substituents in a parent nucleus molecule with the CAS number of 1093856-24-6 of quaterphenyl quaternary ammonium salt. The PCR hot start reagent is suitable for gene cloning, clinical diagnosis, gene detection and other scenes with high specificity requirements, can effectively inhibit non-specific amplification at low temperature, improves the specificity of PCR reaction and product purity, and has popularization and application values.

The invention provides a preparation method of hexafluorobutadiene, which comprises the following steps: 1) carrying out electrophilic addition reaction on chlorotrifluoroethylene and liquid bromine at normal temperature and normal pressure to generate 1, 2-dibromo-1-chloro-1, 2, 2-trifluoroethane; 2) mixing zinc powder, 1, 2-dibromo-1-chloro-1, 2, 2-trifluoroethane and an aprotic polar solvent, and carrying out a reaction so as to obtain a zinc reagent containing 1-chloro-2-bromo-1, 2, 2-trifluoroethyl zinc bromide and 1, 2-dibromo-1, 2, 2-trifluoroethyl zinc chloride; 3) adding a catalyst and a zinc reagent, and carrying out a self-coupling reaction to generate an intermediate product containing 1, 4-dibromo-2, 3-dichloro-1, 1, 2, 3, 4, 4-hexafluorobutane and 1, 2, 3, 4-tetrabromo-1, 1, 2, 3, 4, 4-hexafluorobutane; 4) dehalogenating the intermediate product to generate hexafluorobutadiene; the method has the effects of simple reaction process, relatively low risk, relatively mild reaction conditions and relatively high yield.

Production of HFO-1132 and, in particular, HFO-1132E, is produced from chlorotrifluoroethylene (CTFE) and / or trifluoroethylene (HFO-1123). In a first step, 1,1,2-trifluoroethane (HFC-143) is produced by hydrogenating chlorotrifluoroethylene (CTFE) and / or trifluoroethylene (HFO-1123) by reaction with hydrogen in the presence of a catalyst at a temperature of between about 75°C and about 225°C. The 1,1,2-trifluoroethane (HFC-143) may then be dehydrohalogenated in the presence of a catalyst to produce trans-A,2-difluoroethylene (HFO-1132E) and cis-1,2-difluoroethylene (HFO-1132Z). The cis-1,2-difluoroethylene (HFO-1132Z) may then be isomerized to produce trans-A,2-difluoroethylene (HFO-1132E).

The invention discloses a preparation method of fluorine-containing alkyne, which comprises the following steps: under the action of a catalyst, Rf-CX1 = CHX2 and hydrogen are subjected to hydrodehalogenation reaction to obtain fluorine-containing alkyne Rf-C = CH, in the formula, X1 and X2 are independently selected from Cl, Br or I; rf is CnF2n + 1, and n is a natural number from 1 to 6; the catalyst comprises a carbon carrier and active components which are loaded on the carbon carrier and are of a hollow structure, and the active components comprise at least one first metal selected from silver, copper, nickel and cobalt and at least one second metal selected from palladium, platinum and rhodium. The preparation process has the advantages of high catalytic activity, high product selectivity, easiness in industrial application and the like.

The invention discloses a catalyst for hydrodechlorination reaction and a preparation method thereof. The catalyst is composed of an active component and a carrier, the active component is selected from at least one of metal Pt, Pd, Rh, Ru, Au, Ag, Cu, Ni and Fe, and the carrier comprises one of activated carbon, MgO, Al2O3, SiO2 or TiO2. According to the invention, the active component is anchored on the carrier by adopting a surface inorganic metal chemical method, and the loading capacity and relative proportion of the metal active component are adjusted, so that the activity and target product selectivity of the catalyst in the hydrodechlorination process are improved, and meanwhile, the catalyst is ensured to have a relatively long service life.

A method for producing a fluoroethane represented by the following formula (1):         CH2X1CHX2X3     (1) wherein X1, X2, and X3 each independently represent a hydrogen atom or a fluorine atom, and at least one of X1, X2, and X3 represents a fluorine atom, the method comprising step A of obtaining the fluoroethane from a chlorofluoroethane represented by the following formula (2) in the presence of a catalyst:         CX4ClFCX5X6X7     (2) wherein X4, X5, X6, and X7 each independently represent a hydrogen atom, a fluorine atom, or a chlorine atom, and at least one of X5, X6, and X7 represents a hydrogen atom.

The present application relates to a kind of bromine-mediated propane oxidative dehydrogenation system and method for preparing propylene.The system and method use propane and the bromine recovered by propane dehydrogenation device as raw material, through multi-step reaction and rectification process, including bromination reaction, hydrogenation reaction, dehydrogenation reaction and electrolysis reaction, realize the efficient conversion of propane, finally obtain product propylene and hydrogen.The present application solves the technical problems of low utilization efficiency of propane as fuel and low conversion rate in the process of converting propane to propylene;The present application uses waste heat in multi-step process to recover heat, uses the bromine and hydrogen gas produced by propane dehydrogenation process to recycle reaction, reduces the energy loss in the process, improves the utilization efficiency of material and energy, realizes the flexible improvement of propylene production while fully utilizing propane.

Provided is a method for producing chlorotrifluoroethylene and trifluoroethylene by bringing a raw material composition containing 1,1,2-trichloro-1,2,2-trifluoroethane, hydrogen, and water into contact with a catalyst, the composition having a water content of 200 ppm by mass or less with respect to the entire raw material composition, to produce chlorotrifluoroethylene and trifluoroethylene through a reaction between the 1,1,2-trichloro-1,2,2-trifluoroethane and hydrogen.