123results about "Preparation from carboxylic acid halide" patented technology

The invention discloses a preparation process of benzoyl chloride. The preparation process comprises the following steps of synthesis of benzotrichloride: carrying out temperature reaction on methylbenzene and chlorine under the catalytic action of a catalyst to synthetize a crude benzotrichloride product; synthesis of the benzoyl chloride: continuously stirring and heating the crude benzotrichloride product and benzoic acid to prepare a crude benzoyl chloride product after adding the catalyst; refining of the benzoyl chloride: carrying out reduced pressure distillation on the crude benzoyl chloride product to prepare a refined benzoyl chloride product; recovering benzoyl chloride raffinate, adding water to the benzoyl chloride raffinate which is subjected to the reduced pressure distillation, heating and stirring to transform the benzoyl chloride contained in the raffinate into the benzoic acid, cooling, then separating out benzoic acid. The preparation process disclosed by the invention is easy to safe to operate, effectively shortens the reaction time, achieves the purity of the prepared benzoyl chloride by 99.5%, reduces the environmental pollution by recycling residues, saves the resources, reduces the cost, meets the requirements of pharmaceutical chemicals and can carry out massive industrial production.

The invention discloses a preparation method of trifluoroacetic acid low in synthesis cost. The preparation method comprises the steps of (1) preparing 1,1-difluoro tetrachloroethane from 1,1-difluoroethane or chloride thereof through ultraviolet catalysis and a chlorine reaction; (2) implementing catalytic oxidation on the 1,1-difluoro tetrachloroethane to obtain 1,1-difluoro-1-chloroacetyl chloride, wherein in the catalytic oxidation, mol ratio of the 1,1-difluoro tetrachloroethane to an oxidizing agent is 1: (2-4), dosage of the catalyst is 0.5-5% of the total weight of an reactant, and reaction temperature is 50-70 DEG C; (3) carrying out hydrogen fluoride (HF) fluoridation on the 1,1-difluoro-1-chloroacetyl chloride under the catalyst to obtain trifluoroacetyl fluoride, wherein mol ratio of the 1,1-difluoro-1-chloroacetyl chloride to the HF is 1: (2-3), reaction temperature is 40-60 DEG C, and the catalyst is either antimony or antimony pentachloride; and (4) hydrolyzing the prepared trifluoroacetyl fluoride to obtain trifluoroacetic acid.

The invention discloses a novel process for preparing acetyl bromide, acetic acid and acetic ester from methane, which consists of reacting methane, oxygen and aqueous solution of HBr to obtain CH3Br and CO through catalytic reaction, then subjecting CH3Br and CO to carbonation reaction so as to prepare acetyl bromide in organic medium containing catalyst, then directly hydrolyzing the acetyl bromide and a certain amount of water into acetic acid, and reacting acetyl bromide and alcohols to obtain the acetic esters of the corresponding alcohols. The HBr can be regenerated as circular reaction medium and used again for the reaction for preparing CH3Br and CO from methane. The organic medium of the carbonylation reaction contains catalyst such as rhodium (Rh) compound, hydriodate and/or organo-phosphorus ligand, and a certain proportion of solvents.

A process for recycling a polymer blend necessarily containing PLA, comprising grinding, compacting, dissolving in a solvent of PLA, removing the undissolved contamining polymers, alcoholysis depolymerisation reaction and purification steps.

The invention discloses a method for preparing a special fluoroether surfactant. The method comprises the steps of adding deionized water and a fluoroether oligomer, of which the average molecular weight is 300-1,500, into a hydrolysis reaction kettle according to the weight ratio of about (1: 15) to (3: 1), carrying out stirring heating, maintaining the internal temperature of the kettle to be about 30-200 DEG C, hydrolyzing unstable terminal groups of the fluoroether oligomer into carboxylic acid terminal groups, carrying out reaction for half an hour to 8 hours, then, standing a reaction solution to carry out layering, removing an upper-layer aqueous solution through sucking, adding an approximately equal volume of clean deionized water into the hydrolysis kettle so as to clean reactants, carrying out stirring for about half an hour at normal temperature, then, removing an upper-layer aqueous solution through sucking, repeating the cleaning method for 1-3 times, and discharging the reactant, thereby preparing the fluoroether surfactant containing the carboxylic acid terminal groups.

The invention discloses a fluorosurfactant free of perfluorooctanoic acid as well as a preparation method and a process system of the fluorosurfactant. The fluorosurfactant is a repeated structure unit which comprises at least one oxoperfluoropropenyl and one or a combination of more of perfluoromethoxyl, a Y group and oxoperfluorovinyl and is provided with a carboxyl group or carboxylate at one end. The fluorosurfactant is a fluoropolymer with the C-O-C ether bond structure as the main structural body; in view of indexes, the fluorosurfactant does not contain perfluorooctanoic acid with a 8-C straight-chain structure or salt of the perfluorooctanoic acid, is easily decomposed in nature and is proved to be harmless to human bodies, the peroxide value is 0.001%-0.1%, the surface tension is 10-30 mN/m, and the fluorosurfactant has an amphiphilic structure of a surfactant.

The invention relates to a preparation method of 2-bromo-2,2-difluoroacetyl chloride and 2-bromo-2,2-difluoro acetate and a recycling method of waste difluoro trichloroethane. The preparation method comprises the following steps: with waste difluoro trichloroethane produced in the production process of dichlorotrifluoroethane as a raw material, carrying out dehydrochlorination to obtain difluoro dichloroethylene, carrying out addition reaction on difluoro dichloroethylene and bromine to obtain difluoro dichlone dibromoethane; reacting difluoro dichlone dibromoethane with sulfur trioxide to obtain 2-bromo-2,2-difluoroacetyl chloride; and reacting 2-bromo-2,2-difluoroacetyl chloride with alcohol or phenol to obtain 2-bromo-2,2-difluoro acetate series products. According to the preparation method and the recycling method, recycling of waste difluoro trichloroethane is realized; 2-bromo-2,2-difluoroacetyl chloride and 2-bromo-2,2-difluoro acetate are prepared by a temperature oscillation method, so that the production cost is reduced; and meanwhile, the preparation method is an environment-friendly technique for producing products.

The invention discloses a preparation method for a special fluoroether oligomer which is obtained by carrying out a photochemical polymerization reaction on a special fluorine-containing monomer mixture. The obtained fluoroether oligomer has many previously unimagined valuable applications. The fluoroether oligomer with the average molecular weight of 300-1500, the viscosity of about 1-20 cPs at 25 DEG C and the acidic value of about 70-100 is suitable for being used as a fluoroether surfactant and further can be used as a perfluoro caprylic acid substituent. The fluoroether oligomer with the average molecular weight over 1500 and the viscosity of about 20-500 cPs at 25 DEG C is further suitable for important applications of being processed as fluoroether oil and high-temperature-resistant lubricating oil and the like. The products or mixture thereof can be further used as an auxiliary for a polymerization process of special fluororubber, particularly low-temperature fluororubber. The low-temperature resistance can reach (-40) DEG C, so that the special fluoroether oligomer can be further accepted in markets of space flight and aviation and automobile industry.

The invention relates to a method for preparing 2-chloro-6-fluorobenzaldehyde, and belongs to the technical field of organic synthesis. The method for preparing 2-chloro-6-fluorobenzaldehyde comprises the following steps of: performing chlorination on 2-chloro-6-fluorotoluene under illumination to obtain 2-chloro-6-fluorobenzyl chloride, 2-chloro-6-difluorobenzyl chloride, and 2-chloro-6-trifluorobenzyl chloride; when the content of 2-chloro-6-fluorobenzyl chloride is less than 0.5 percent, adding ferric solid superacid, dripping water at the temperature of between 100 and 200 DEG C, and preserving heat for 4+/-5 hours; and adding alkali liquor, stirring to ensure that a liquid phase is layered, and performing reduced pressure distillation or rectification and purification on an organic phase which is obtained after the liquid phase is layered to obtain 2-chloro-6-fluorobenzaldehyde.

The present invention relates to a method for preparing a halogenocetyl fluoride and the derivatives thereof. The inventive method for preparing a halogenocetyl fluoride acid is characterised in that said method includes: a step of preparing a halogenoacetyl halide by photo-oxidation of a halogenoethylene compound in conditions such that the transformation rate of the halogenoethylene compound into halogenoacetyl halide is no higher than 80 %, producing a reaction mixture essentially including halogenoacetyl halide and the excess halogenoethylene compound; a step of partial fluorination of the mixture obtained by reacting the latter with hydrofluoric acid suitable for obtaining a mixture of halogenoacetyl fluoride and the excess halogenoethylene compound; a step of separating the halogenoacetyl fluoride and the excess halogenoethylene compound. The invention can be used, specifically, for preparing the trichloroacetyl fluoride used as an intermediate species in the production of trifluoroacetic acid.

Hydrofluoroethers of formula:

T-CFX′—O—R_f—CFX-T′  (II)

wherein:

• T=CH₃;
• X, X′, equal to or different from each other, are selected between F, CF₃;
• T′=F, Cl, H, C₁—C₃ perfluoroalkyl, CH₃, CH₂0H, COC₁, CHO, CO₂H;
• R_f is a perfluoroalkylene or a perfluoropolyoxyalkylene and respective preparation process by reduction with hydrogen in the presence of a platinum catalyst supported on metal fluorides of the corresponding compounds with at least one —COCl end group.

The invention belongs to the field of fluorine chemical and particularly relates to a method for comprehensively utilizing byproducts produced in HFPO (hexafluoropropylene oxide) preparation based onan oxygen oxidation method. The method comprises following steps: 1), oxygen and hexafluoropropylene are taken as raw materials, and HFPO is prepared under the action of a fluoride solvent, and the fluoride solvent is recycled; 2), when content of the byproducts in the recycled fluoride solvent is lower than 40wt%, ultraviolet irradiation is performed every 10-30 h; 3), when content of the byproducts is higher than or equal to 40wt%, water is added to the fluoride solvent, and a carboxylic acid product is obtained. On one hand, an important chemical intermediate carbonyl fluoride in the fluorine chemical can be obtained, on the other hand, the byproducts can be converted into a perfluoro surfactant or fluorine-containing fluid for further application, and therefore, the byproducts producedin the HFPO preparation process based on the oxygen oxidation method are comprehensively utilized.

Methods for making acrylic acid, acrylic acid derivatives, or mixtures thereof by contacting a stream containing hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof with either an active catalyst containing an amorphous and partially-dehydrated phosphate salt or a precursor catalyst containing a crystalline phosphate salt in a reactor with a low corrosion rate are provided.

In the production of carboxylic acid or carboxylic acid ester, a reaction product containing the carboxylic acid or carboxylic acid ester which has been produced by the reaction of an olefin, carbon monoxide, and water or an alcohol in the presence of HF is heat-treated in the presence of an acid catalyst and an acid adsorbent. By the heat treatment, the contamination of the carboxylic acid or carboxylic acid ester with HF and/or fluorine compounds such as acyl fluorides can be prevented, to enable the stable production of a high quality and high purity carboxylic acid or carboxylic acid ester without causing troubles such as corrosion of apparatus.

This invention relates to a perfluorooctanoic acid preparation method, belong to fluorine chemicals technology field. It takes electrolysis fluorine hydride and octanoyl chlorine electrolyte as materials, the main ingredients is perfluorooctanoic acid fluoride. First use liquid alkali to alkaline hydrolyze electrolyte containing perfluorooctanoic acid fluorine, isolate part of sodium fluoride and the main byproduct of fluorocarbon, obtain perfluorooctanoic acid solution of sodium, then use sulfate for acidification, gain perfluorooctanoic acid. Through organic and water phase separation to remove some of the residual hydrogen fluoride, the organic phase by means of distillation purification, to obtain perfluorooctanoic acid products. The invention can improve the yield of perfluorooctanoic acid products while enhancing straight chain content.