16results about "Preparation by halogen addition" patented technology

The invention relates to bio-based vinylidene difluoride. The invention also relates to processes for preparing bio-based vinylidene difluoride from various renewable raw materials. The invention further relates to vinylidene difluoride homopolymers obtained by polymerization of said monomer, as well as copolymers obtained by copolymerization of said monomer with one or more compatible co-monomers. Finally, the invention relates to the use of said homopolymers or copolymers in applications such as chemical engineering or electronics, particularly consumer electronic devices.

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.

Alkyne compounds are produced by contacting a 1-alkene with chlorine, optionally in the presence of a halide salt, to form a 1,2-dichloroalkane compound, then optionally contacting the 1,2-dichloroalkane compound with a catalyst to form a chloroalkene compound, and then contacting the 1,2-dichloroalkane compound and / or the chloroalkene compound with a base and a phase transfer catalyst to form a reaction mixture comprising a 1-alkyne and / or a 2-alkyne. Representative alkynes that can be produced using this process include 1-hexyne, 2-hexyne, 2-heptyne, and the like.

This invention discloses a method for preparing 2,3,3,3-tetrafluoropropylene, comprising reacting carbon tetrachloride with ethylene in the presence of a catalyst containing reduced iron powder and a co-catalyst, separating and purifying the reactants to obtain HCC-250fb; subjecting HCC-250fb to dehydrochlorination to generate HCC-1240za; reacting HCC-250fb with chlorine in a liquid-phase or gas-phase chlorination reaction to obtain HCC-240db; reacting HCC-240db with hydrogen fluoride in a gas-phase fluorination reaction to generate HCFO-1233xf; and reacting HCFO-1233xf with hydrogen fluoride in a gas-phase fluorination reaction in the presence of a supported or unsupported chromium oxide catalyst to generate HFO-1234yf. The method of this invention uses readily available raw materials, has low cost, and allows unreacted raw materials to be recycled for further reactions, resulting in minimal waste emissions.

The present disclosure features methods for modulating the production of a small halogenated organic compound from a microalgae, as well as related compositions and methods thereof.

This invention belongs to the field of fine chemical engineering and organic synthesis technology, and relates to a method for preparing high-purity 1,1-difluoro-2-iodoethylene. The method includes: firstly, in an aprotic organic solvent, under controlled low-temperature conditions, allowing vinylidene fluoride to undergo an addition reaction with iodine monochloride to obtain the intermediate 1-chloro-1,1-difluoro-2-iodoethane; subsequently, the intermediate undergoes a controlled elimination reaction in an alkaline aqueous solution, and the product is immediately removed by reactive distillation, finally purified by distillation to obtain the target product. This invention effectively controls the thermal effect of the addition reaction by introducing a specific solvent, suppressing side reactions such as iodine radical coupling, and eliminating the need for expensive metal catalysts or phase transfer catalysts. The process is simple and safe to operate, with an intermediate separation yield of over 95%, high overall yield, and high product purity, making it suitable for large-scale industrial production.

This invention discloses a method for preparing 2,3,3,3-tetrafluoropropylene. Using ethylene and carbon tetrachloride as raw materials, 1,1,1,3-tetrachloropropane (HCC-250fb) is first prepared. Then, 1,1,1,3-tetrachloropropane is decomposed to obtain 1,1,3-trichloropropene (HCC-1240za). This 1,1,3-trichloropropene is then reacted with chlorine to generate 1,1,1,2,3-pentachloropropane (HCC-240db). The 1,1,1,2,3-pentachloropropane is then decomposed to obtain 1,1,2,3-tetrachloropropene (HCC-1230xa). The 1,1,2,3-tetrachloropropene is reacted with hydrofluoric acid to generate 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf). Finally, 2,3,3,3-tetrafluoropropylene is prepared using two different methods. This invention has low raw material costs and high yield.

Disclosed herein is a method of intermolecular C-H fluorination of an aromatic compound (e.g., a compound including at least one aromatic moiety), the method including: a) contacting the aromatic compound with a fluorine donor in the presence of a biocatalyst and at least one photosensitizer, thereby forming a mixture; b) irradiating the mixture with electromagnetic radiation, thereby photoexciting the at least one photosensitizer, which initiates radical transformation to thereby intermolecularly fluorinate the aromatic compound to form a fluorinated aromatic compound (e.g., a fluorinated compound including at least one aromatic moiety). Also disclosed are fluorinated aromatic compounds and biocatalysts for intermolecular C-H fluorination.

This invention discloses a method for preparing cis-1,2-dibromoethylene based on steric hindrance, belonging to the field of technical organic synthesis. The method includes the following steps: (a) providing reactors A and B connected in series. Bromine is added to reactor A, and a solvent and configuration-selective catalyst are added to reactor B. This invention employs a series reactor system. Under the synergistic effect of a copper / crown ether composite catalyst and ultraviolet light, a highly selective addition reaction of acetylene with bromine is achieved by controlling the solvent system, reaction temperature, and material ratio. Using acetonitrile or perfluoroalkane as solvent, and copper chloride and crown ethers (such as 15-crown-5) as catalysts, the reaction is carried out at 30-80℃ under 200-400nm ultraviolet light. The selectivity of cis-1,2-dibromoethylene is ≥95%, which has advantages such as mild reaction conditions, solvent recyclability, and suitability for industrial production. Furthermore, the cis selectivity is improved to ≥95%; the content of the byproduct tetrabromoethane is <0.5%; and the solvent recovery rate is >98%.

The invention provides a novel process route for preparing perfluorohexane (C6F14), and the preparation method comprises the following steps: diluting fluorine gas with inert gas to obtain first mixed gas, and mixing hexafluoropropylene dimer (C6F12) with perfluorinated liquid to obtain first mixed liquid; the first mixed gas and the first mixed solution are treated through a microchannel reactor and then transferred into a reaction kettle, a product in the reaction kettle is collected, the product is separated, and the crude perfluorohexane product is obtained. The problems that in the prior art, the C6F14 preparation process is complex, and the conversion rate is low are solved. On the other hand, the invention discloses a purification method for obtaining a high-purity C6F14 finished product. The conversion rate and the purity of the perfluorohexane obtained by the scheme of the invention are obviously improved.

The present invention aims at that in a series of processes of producing 1,2,3,4-tetrachlorohexafluorobutane from 1,3-butadiene, by-products can be converted to a target substance by a relatively simple operation, raising the production efficiency as the whole process. There is provided a method for producing 1,2,3,4-tetrachloro-1,1,2,3,4,4-hexafluorobutane comprising step (a) of reacting chlorofluorobutane represented by the formula (1): C4ClnF10-n (1), wherein n is an integer satisfying 5 ≤ n ≤ 7, with chlorine monofluoride (ClF) to thereby produce 1,2,3,4-tetrachloro-1,1,2,3,4,4-hexafluorobutane.

This invention provides a method for preparing 1,2-difluorotetrachloroethane, relating to the field of 1,2-difluorotetrachloroethane preparation technology. A mixture of halogenated ethylene and halogenated nitrogen is introduced into a gas-liquid phase microchannel reactor, where an addition reaction yields crude 1,2-difluorotetrachloroethane, which is then refined using a purification system to obtain the final product. Compared to traditional methods, the reaction conditions are milder, eliminating the need for high temperature and high pressure, thus significantly reducing energy consumption and improving operational safety. Furthermore, due to the highly efficient mass and heat transfer characteristics of the microchannel reactor, the reaction time is greatly shortened, further reducing energy consumption.

The present invention relates to a method for chlorination and bromination reactions of olefins using environmentally friendly TBAX (Br, Cl) and Selectfluor salts as an alternative to metal and toxic halogen sources for chlorination and bromination reactions of olefins, eliminating the problems caused by classical halogenation methods, metal-free, non-toxic and simple operating conditions.

This invention relates to the field of haloalkanes preparation, specifically to a method and apparatus for simultaneously preparing multiple perfluoroalkanes. The method includes the following steps: (1) thermally cracking polytetrafluoroethylene to form a pyrolysis gas containing fluoroolefins; (2) reacting the pyrolysis gas with fluorine gas to form crude perfluoroalkanes gas; (3) subjecting the crude perfluoroalkanes gas to deep catalytic fluorination under the action of a catalyst to remove fluoroolefins, followed by distillation to obtain hexafluoroethane, octafluoropropane, or hexafluoroethane, octafluoropropane, octafluorocyclobutane, and decafluorobutane, respectively. This invention achieves the preparation of high-purity perfluoroalkanes such as hexafluoroethane, octafluoropropane, octafluorocyclobutane, and decafluorobutane through pyrolysis, fluorine addition, catalytic fluorination, and distillation processes, featuring low cost, high efficiency, and suitability for industrial production.

A method for the production of 1,2-dichloroethane, the method comprising (i) providing a fluidizable catalyst; (ii) charging the fluidizable catalyst to a fluidized bed reactor; (iii) fluidizing the catalyst within the reactor; (iv) heating the catalyst to a temperature of greater than 150° C. for greater than 6 hours within the fluidized bed reactor while fluidizing the catalyst within the reactor, where said steps of fluidizing and heating take place in the absence of the conversion of ethylene; and (v) after said step of heating, converting ethylene to 1,2-dirchloroethane in the presence of the catalyst.