23 results about "Dehydrohalogenation" patented technology

Disclosed herein is a method for preparing a perfluorobisfluorosulfonyl monomer. Specifically, disclosed herein is a method for preparing a compound of Formula II, comprising the step of: subjecting a compound of Formula III to a sulfinic dehalogenation reaction as shown below in the presence of a sulfinic dehalogenation reagent in an organic solvent to obtain the compound of Formula II. The method of the present application is a method for preparing an intermediate of a perfluorobisfluorosulfonyl monomer, and is also a key step in a method for preparing a perfluorobisfluorosulfonyl monomer. The method of the present application is simple to purify and has a relatively high yield.

The invention provides a preparation method of a perfluoroalkenyl ether iodine-containing vulcanization point monomer. Specifically, the invention provides a preparation method of a compound as shown in a formula I. The preparation method comprises the following steps: in an aprotic solvent, in the presence of a dehalogenating agent, a compound as shown in a formula II is subjected to a dehalogenating reaction to generate the compound as shown in the formula I, the dehalogenating agent is a metal or organic metal compound; the metal is mixed metal of two or three of zinc, copper and palladium; the organic metal compound is an organic metal zinc reagent or an organic metal magnesium reagent. The preparation method is low in cost, high in yield, convenient and fast.

The invention discloses a thieno-imidazole strong reduction type photocatalyst as well as synthesis and application thereof, and belongs to the technical field of organic chemistry. The chemical structural general formula of the thieno-imidazole strong reduction type photocatalyst is shown in the specification, 2, 5-dibromo-3, 4-dinitrothiophene and arylboronic acid are used as raw materials, the thieno-imidazole strong reduction type photocatalyst is prepared after three-step reaction of coupling, reduction and condensation / methylation, and the obtained thieno-imidazole strong reduction type photocatalyst is good in yield and strong in substrate applicability in reductive dehalogenation reaction. The application range of the photocatalyst is expanded, and a new solution is provided for efficient and environment-friendly dehalogenation synthesis.

To obtain a halogenated alkene compound and a halogenated alkyne compound in high conversion and high selectivity.SOLUTION: Any one of the following methods (1) to (4) is employed: (1) CX1X2X3CHX4CFHCX5X6X7 wherein X1, X2, X3, X4, X5, X6, and X7 are identical or different and are halogen atoms. (2) CX1X2X3CX4 = CHCX5X6X7 [X1, X2, X3, X4, X5, X6, and X7 are as defined above]. (3) CHX8A1CHX9A2 wherein A1 and A2 are each independently a halogen atom or a perfluoroalkyl group. X8 and X9 are identical to or different from each other and each represent a halogen atom; (4) CX8A1 = CHA2 [wherein A1, A2 and X8 are as defined above] is subjected to a dehydrohalogenation reaction in the gas phase in the presence of a catalyst. Is subjected to a dehydrohalogenation reaction in the presence of a catalyst.SELECTED DRAWING: None

The invention discloses a synthesis method of hydroxymethylenediphosphonic acid disodium salt, and relates to the field of radiopharmaceuticals, the synthesis method comprises the following steps: S1, tetraisopropyl methylenediphosphonate is subjected to a substitution reaction in a sodium hypochlorite solution to obtain tetraisopropyl dichloromethylenediphosphonate; s2, carrying out a dehalogenation reaction on the tetraisopropyl dichloromethylene diphosphate in a sodium sulfite solution to obtain tetraisopropyl monochloromethylene diphosphate; s3, carrying out a hydrolysis reaction on the tetraisopropyl monochloromethylenediphosphonate, so as to obtain pyridinium monochloromethylenediphosphonate; and S4, carrying out substitution reaction on the monochloromethylenediphosphonic acid pyridinium salt to obtain the hydroxymethylenediphosphonic acid disodium salt. The adopted raw materials and reagents are wide in source, low in price and easy to obtain, high-risk or highly-toxic chemicals are not contained, the technological process is environmentally friendly, the development direction of green chemistry is met, and good industrial application prospects are achieved.

The invention discloses a synthetic method of perfluoroalkoxy methylene vinyl ether, which comprises the following steps of: 1, reacting alkyl fluoroformate with halogenated olefin under the action of an auxiliary agent to generate halogenated alkyl ether, and performing dehalogenation reaction to generate perfluoroalkoxy methylene vinyl ether; the method II comprises the following steps: reacting alkyl fluoroformate with hexafluoropropylene oxide under the action of an auxiliary agent to generate alkoxy propionyl fluoride, and carrying out salification and decarboxylation reaction to generate perfluoroalkoxy methylene vinyl ether (RfOCF2OCF = CF2); the auxiliary agent is metal fluoride or fluoro quaternary ammonium salt. In the first method and the second method, the alkyl fluoroformate and the halogenated olefin or the hexafluoropropylene oxide need to react under the action of the aid (metal fluoride or fluoro quaternary ammonium salt), so that the safety problem caused by direct use of fluorine gas is avoided, and the conversion rate of the trifluoromethyl fluoroformate and the yield and selectivity of the product can be improved.

The present disclosure mainly addresses the problem of providing a novel method for producing a fluoroolefin.　Provided as a solution is a method for producing a fluoroolefin represented by general formula (1): CX1X2=CX3X4 (where X1, X2, X3, and X4 are identical or different and each represent a hydrogen atom, a fluorine atom, or a chlorine atom, and at least one of X1, X2, X3, and X4 is a fluorine atom), said method comprising a dehydrohalogenation step for bringing a fluorocarbon represented by general formula (2): CX1X2HCX3X4Y (where X1, X2, X3, and X4 are the same as above, and Y is a fluorine atom or a chlorine atom) into contact with a noble metal catalyst to perform dehydrohalogenation.

The invention relates to an integrated process for making fluorinated olefins. The present invention relates, at least in part, to a method for increasing the cost efficiency of a dehydrohalogenation production process of fluorinated olefins by recovering and recycling a spent dehydrohalogenation agent. In one aspect, the invention relates to dehydrohalogenating fluorinated alkanes (e.g., pentafluoropropane and / or hexafluoropropane) in the presence of a dehydrohalogenating agent to produce fluorinated alkenes (e.g., tetrafluoropropene and / or pentafluoropropene). Removal of the spent dehydrohalogenating agent from the reactor makes the organic matter readily separated from the dehydrohalogenating agent, the latter being recycled.

The invention discloses a catalyst and a preparation method and application thereof.According to the catalyst, cobalt phosphide serves as an active component, the active component and auxiliary metal are loaded on a mesoporous carrier, the mesoporous carrier can improve the stability of the catalyst and prolong the service life of the catalyst, and the activity of the catalyst cannot be obviously reduced after the catalyst operates for a long time; and the synergistic effect of the active component and the auxiliary metal can improve the conversion rate of the raw materials and improve the selectivity of the product. Meanwhile, the catalyst taking the phosphide of cobalt as the active component can also enable the dehydrohalogenation reaction of chlorofluorocarbon to be carried out at a relatively low temperature (such as 280 DEG C or below), so that the production cost is saved.

The invention discloses a selective unilateral dehalogenation method of an alpha, omega-diiodo-ethyl perfluoroalkane compound, which comprises the following steps: (1) continuously introducing alpha, omega-diiodo-ethyl perfluoroalkane and an alkali solution containing a phase transfer catalyst into a supergravity reactor for dehalogenation reaction, the generated reaction liquid overflows from an overflow port of the supergravity reactor; and (2) separating the reaction liquid overflowed in the step (1) to obtain an iodized salt aqueous solution and a crude product of alpha, omega-iodinated ethyl vinyl perfluoroalkane, and rectifying and purifying the crude product to obtain the alpha, omega-iodinated ethyl vinyl perfluoroalkane. According to the method, the mass transfer effect is enhanced by adopting the supergravity reactor, the alpha, omega-iodo-ethyl vinyl perfluoroalkane compound is prepared by highly selectively performing unilateral dehalogenation on the alpha, omega-diiodo-ethyl perfluoroalkane in combination with regulation and control on the feeding molar ratio of alkali, the raw material conversion rate is greater than or equal to 79%, and the unilateral dehalogenation selectivity is greater than or equal to 85%.

The present invention relates to a process for the dehydrohalogenation of a halogenated hydrocarbon comprising at least one halogen atom (X) and at least one hydrogen atom on vicinal carbon atoms to yield the corresponding unsaturated hydrocarbon, said process comprising contacting at a temperature T1 ranging from 40°C to 200 °C the halogenated hydrocarbon with a sulfoxide containing resin, optionally in the presence of a base; wherein the sulfoxide containing resin comprises a plurality of sulfoxide groups and is free of hydrolysable groups; and wherein halogen atom (X) is selected from F, Cl, Br and I.

The invention discloses ammonium fluoride etched micron zero-valent iron-nickel particles based on mechanical ball milling as well as a preparation method and application of the ammonium fluoride etched micron zero-valent iron-nickel particles. The micron zero-valent iron-nickel particles are mainly prepared by mixing micron zero-valent iron, ammonium fluoride and a transition metal nickel compound through a mechanical ball-milling etching-loading process, the transition metal nickel compound is mainly composed of nickel chloride hexahydrate, and the mass ratio of the micron zero-valent iron to the ammonium fluoride to the nickel chloride hexahydrate is 1: (0.01-0.04): (0.02-0.08). Ammonium fluoride is added for modifying and improving the dehalogenation performance of the iron-nickel particles. The reductive dehalogenation reaction activity of the particles on halogenated organic matters is remarkably improved, and the particles still keep stable performance after being recycled for more than 20 times and are not obviously attenuated; meanwhile, halogen functional groups in aliphatic halides and aryl halides can be efficiently reduced and removed, and excellent water treatment application potential is shown.

The invention relates to the technical field of plastic recycling, and discloses a double-screw extruder for plastic waste recycling, which comprises a base, the top end of the base is connected with a plurality of groups of support frames, the top ends of the support frames are connected with an extrusion cylinder, and the extrusion cylinder is internally connected with an integrated screw. The extrusion barrel comprises a melting compression section, one end of the melting compression section is connected with a dehalogenation reaction section, the other end of the dehalogenation reaction section is connected with a melting homogenization section, the other end of the melting homogenization section is provided with a devolatilization section, the other end of the devolatilization section is connected with a repair section, and the other end of the repair section is connected with an extrusion section. Through the integrated and modularized structural design, the whole-process continuous treatment of plastic melting, dehalogenation purification, efficient devolatilization and molecular repair is realized in single equipment.

The invention discloses a preparation method of (E)-1, 1, 1, 2, 2, 5, 5, 6, 6, 6-decafluorohexyl-3-ene, and the preparation method comprises the following steps: carrying out telomerization reaction on 1, 1-difluoroethane, tetrafluoroethylene and HF in the presence of a catalyst to prepare 1, 1, 1, 2, 2, 5, 5, 6, 6, 6-decafluorohexane, and then carrying out halogenation and dehydrohalogenation reaction to prepare (E)-1, 1, 1, 2, 2, 5, 5, 6, 6, 6-decafluorohexyl-3-ene. The preparation method provided by the invention has the advantages of cheap and easily available raw materials and high product selectivity.

This invention discloses a method for preparing 6-bromo-6,6-difluoro-1-hexanol, belonging to the field of organic synthesis. The method uses 4-penten-1-ol as a starting material, reacting it with dibromodifluoromethane via an addition reaction to prepare 4,6-dibromo-6,6-difluoro-1-hexanol; then, a dehalogenation reaction is carried out using a second metal reagent to obtain 6-bromo-6,6-difluoro-1-hexanol. In this method, the reactants and reagents are inexpensive and readily available, the reaction steps are short, and production control is convenient; the reaction conditions are mild, ensuring high safety; the process is simple, and the product has high purity.

Provided is a curable resin capable of giving a cured object having satisfactory heat resistance. The curable resin is obtained by subjecting a product of reaction between a haloethylbenzene represented by formula (2A) and a vinylbenzyl halide represented by formula (3A) to a dehydrohalogenation reaction.

The invention relates to tamsulosin, in particular to a tamsulosin chiral amine preparation method. According to the method, Fmoc-p-methoxy-L-phenylalanine which is low in cost and can be commercially purchased is used as a raw material, and the Fmoc-p-methoxy-L- The method comprises the following steps: 1) carrying out a reduction reaction on a compound A (Fmoc-p-methoxy-L-phenylalanine) and borane to obtain a compound B; 2) carrying out Appel reaction on the compound B to obtain a compound C; 3) performing hydrodehalogenation reaction on the compound C to obtain a compound D; the invention provides a preparation method of tamsulosin chiral amine, which comprises the following steps: (1) carrying out a sulfonation reaction on a compound D and chlorosulfonic acid, and reacting with ammonia water to obtain a compound E. (5) carrying out deprotection on the compound E to obtain a compound F (tamsulosin chiral amine). The preparation method of tamsulosin chiral amine is a brand new preparation method of tamsulosin chiral amine, and has the advantages of simple route, cheap and easily available raw materials, mild conditions and high reaction yield, and greatly reduces the production cost of tamsulosin.

The invention relates to an integrated process for making fluorinated olefins. The present invention relates, at least in part, to a method for increasing the cost efficiency of a dehydrohalogenation production process of fluorinated olefins by recovering and recycling a spent dehydrohalogenation agent. In one aspect, the invention relates to dehydrohalogenating fluorinated alkanes (e.g., pentafluoropropane and / or hexafluoropropane) in the presence of a dehydrohalogenating agent to produce fluorinated alkenes (e.g., tetrafluoropropene and / or pentafluoropropene). Removal of the spent dehydrohalogenating agent from the reactor makes the organic matter readily separated from the dehydrohalogenating agent, the latter being recycled.

The invention relates to a process for the preparation of a halogenated 1,3-butadiene by dehydrohalogenation of a halogenated 1-butene. Preferably, 2-chloro-1,3-butadiene (CP) is prepared from 3,4-di- chloro-1-butene (3,4-DBN), or 2,3-dichloro-1,3-butadiene (DCB) is prepared from 2,3,4-trichloro-1- butene (TCB). The dehydrohalogenation is performed in the presence of an organic base, preferably selected from (i) non-polymeric organic bases and (ii) polymeric organic bases. Upon dehydrohalogenation of the halogenated 1-butene, the organic base preferably provides an organic halide salt, namely (i) a low melting organic halide salt, which is an ionic liquid; or (ii) a polymeric organic halide salt. Preferably, halogenated 1,3-butadiene is separated from the reaction mixture by in-situ distillation. Organic base is preferably recovered from (i) the low melting organic halide salt by e.g. heating and release of hydrohalogenic acid; or from (ii) the polymeric organic halide salt by e.g. reconversion of polymeric organic halide salt into polymeric organic base and an inorganic halide salt, and size-based separation of the inorganic halide salt, preferably by filtration, more preferably selected from microfiltration, ultrafiltration and nanofiltration, still more preferably by nanofiltration. After purification, recovered organic base is preferably recycled into the process.

The invention discloses a preparation method of fluorinated alkene ether, which comprises the following steps: replacing alkene CFCl = CFCl in a 1, 2-difluorodichloroethylene method with hydrogen-containing fluorinated alkene CFH = CFX, carrying out fluorination reaction on the fluorinated alkene CFH = CFX, fluorine gas and fluorinated acyl fluoride (RCOF) under the action of a catalyst, and directly generating an intermediate (namely a fluorinated ether isomer mixture comprising RCF2OCFHCF2X and an isomer thereof RCF2OCFXCF2H) in one step, the intermediate continues to be subjected to a dehydrohalogenation reaction with alkali, and the product fluorinated alkene ether (RCF2OCF = CF2) is obtained. According to the method, synthesis, use and storage of an unstable intermediate, namely, hypofluoro acid ester RCF2OF with strong oxidation and high explosion risk can be effectively avoided, meanwhile, decomposition caused in the reaction process of special unstable raw material acyl fluoride such as ROCOF and fluorine gas can be reduced, and the safety is effectively improved; the problems of heavy metal use and pollution caused by a zinc powder dehalogenation process in a 1, 2-difluorodichloroethylene method are solved; the method has the advantages of short process flow, mild reaction conditions, environmental protection, high product purity and the like.

The invention relates to a process for the preparation of a halogenated 1,3-butadiene by dehydrohalogenation of a halogenated 1-butene. Preferably, 2-chloro-1,3-butadiene (CP) is prepared from 3,4-di- chloro-1-butene (3,4-DBN), or 2,3-dichloro-1,3-butadiene (DCB) is prepared from 2,3,4-trichloro-1- butene (TCB). The dehydrohalogenation is performed in the presence of an organic base, preferably selected from (i) non-polymeric organic bases and (ii) polymeric organic bases. Upon dehydrohalogenation of the halogenated 1-butene, the organic base preferably provides an organic halide salt, namely (i) a low melting organic halide salt, which is an ionic liquid; or (ii) a polymeric organic halide salt. Preferably, halogenated 1,3-butadiene is separated from the reaction mixture by in-situ distillation. Organic base is preferably recovered from (i) the low melting organic halide salt by e.g. heating and release of hydrohalogenic acid; or from (ii) the polymeric organic halide salt by e.g. reconversion of polymeric organic halide salt into polymeric organic base and an inorganic halide salt, and size-based separation of the inorganic halide salt, preferably by filtration, more preferably selected from microfiltration, ultrafiltration and nanofiltration, still more preferably by nanofiltration. After purification, recovered organic base is preferably recycled into the process.