141 results about "Difluoroacetic acid" patented technology

The invention mainly discloses a processing technique of ethyl difluoroacetate, which mainly comprises the following steps of: preparing an intermediate product dichloroacetyl diethylamine through an amination process; carrying out fluorination with anhydrous potassium fluoride and the dichloroacetyl diethylamine as raw material under the action of a solvent and a phase transfer catalyst to prepare difluoro-acetyl diethylamine; and carrying out esterification to prepare the ethyl difluoroacetate. The processing technique of the ethyl difluoroacetate is characterized in that the solvent in the fluorination is sulfolane, and the esterification is a direction reaction of ethanol and the difluoro-acetyl diethylamine. The processing technique of the ethyl difluoroacetate specifically has the advantages of improving the final yield by changing the solvent during the fluorination and improving the production rate by carrying out the direct esterification after the fluorination.

The invention discloses an industrialized synthetic method of ethyl difluoroacetate. Difluoroacetate is generated through catalysis of difluoroacetamide and low alcohols under strong acid, and the selectivity of the difluoroacetate reaches more than 95%. The method is characterized in that dichloro-acetamide is prepared from secondary amide that is easy to recover and can be in continuous operation at the same time, the problem that fluorine substitution reaction is difficult to carry out under the combination of a common solvent and a catalyst is solved through a solvent, and the solvent has the effect of a phase transfer agent, and is low in cost and convenient to recover.

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 method for preparing difluoroethanol and aims at solving problems of long reaction time and low yield. Difluoro-acetic acid ester serves as the raw material, and the method includes the following steps: adding catalysts, difluoro-acetic acid ester and ethanol into a reaction kettle, leading hydrogen pressure to be 5-10MPa, stirring to lead temperature to rise to 180-250 DEG C, and reacting for 6-10h to obtain difluoroethanol, wherein mass ratio of catalysts: difluoro-acetic acid ester: ethanol is 1: (6.25-12.5):(12.5-18.75). According to mass percent, the catalysts are composed of 40-70% of copper oxide, 10-50% of aluminum oxide, 5-30% of manganese oxide and 5-30% of barium monoxide. The method is mainly used for preparing difluoroethanol.

The present invention discloses a preparation method of difluoro acetate. In the method, difluoro acetonitrile is used as raw material and reacts with alcohol and water to further synthesize the difluoro acetate with a catalyst; the temperature of the synthesis is between 0 DEG C and the reflux temperature of the reaction solution; the molar ratio of the difluoro acetonitrile, the catalyst, the alcohol and the water is equal to 1 : 0.5 to 10.0 : 0.5 to 10.0 : 0.5 to 5.0; the reaction solution can be refined to prepare the difluoro acetate, or extracted, delaminated and refined to prepare the difluoro acetate. The method can be used for preparing the difluoro acetate with high yield rate and high purity. With an appropriate ratio, the transformation ratios of the raw materials exceed 99.0 percent; the selectivity of various esters can exceed 95.0 percent; the yield rate is more than 85 percent. The purity of the synthesized product is more than or equal to 99.5 percent and is suitable for the needs in various aspects. The method has the advantages of short technical process, simple operation, high yield, less three-waste, high purity of the product and so on.

The invention discloses a method for preparing difluoroethanol by gas phase catalytic hydrogenation. The method comprises the following steps: in the presence of a catalyst, mixing difluoroacetate and hydrogen in a molar ratio of 1:(1-10); carrying out a reaction under conditions that the reaction temperature is 100-400 DEG C, the reaction pressure is ordinary pressure and the reaction idling speed is 1-100/s<-1>; and collecting a reaction product and rectifying to obtain the difluoroethanol. The method disclosed by the invention has the advantages of mild reaction temperature, high raw material conversion ratio, good product selectivity and low cost.

The invention discloses a method for synthesizing ethyl 4,4-difluoroacetoacetate in a catalyzed mode through layered materials. The method includes the following steps: 1, a divalent and trivalent metal salt solution and a sodium hydroxide and sodium carbonate mixed solution are rapidly mixed to prepare multielement hydrotalcite, the multielement hydrotalcite is roasted to be added into a fluoride-salt saturation aqueous solution, the mixture is stirred, filtered, washed and dried to be roasted under the nitrogen condition, and catalysts are obtained; 2, ethyl acetate, ethyl difluoroacetate and the catalysts are added into a four-opening flask, an ethyl alcohol and ethyl acetate mixture is evaporated after temperature rising, stirring and reacting are carried out, cooling is carried out, catalysts are filtered and recycled, filtrate is acidized, cooled and filtered, and pressure reduction rectification is carried out on the filtrate to obtain the ethyl 4,4-difluoroacetoacetate; 3, the recycled catalysts are sufficiently washed through solvents and roasted to be added into a fluoride-salt saturation aqueous solution, the mixture is stirred, filtered, washed and dried to be roasted under the nitrogen condition, and the catalysts are regenerated. The method has the advantages that the yield is high, the catalysts can be recycled, and the method is safe and environmentally friendly.

The invention discloses an aryl sulfuryl difluoroacetic salt compound, as well as a preparation method and application thereof. The aryl sulfuryl difluoroacetic salt compound reacts with aldehyde at room temperature to obtain an aryl sulfuryl substituted alpha-difluoromethyl alcohol compound. The aryl sulfuryl difluoroacetic salt compound has the beneficial effects of mild reaction condition, high product yield, few side effect and high universality when the aryl sulfuryl difluoroacetic salt compound is adopted to prepare the aryl sulfuryl substituted alpha-difluoromethyl alcohol compound.

The present invention relates to a method for preparing difluoroacetic acid esters. The method of the invention for preparing difluoroacetic acid esters is characterized in that it includes reacting difluoroacetyl fluorine with an aliphatic or cycloaliphatic alcohol in the presence of a heterogeneous mineral base.

The invention discloses a preparation method of 3-(difluoromethyl)-1-methyl-1H-pyrazol-4-carboxylic acid. The reaction formula is shown in the specification. Difluoroacetic acid, which is relatively low in price and small in molar mass and is introduced at a post-synthesis phase is adopted, so that the preparation method of the 3-(difluoromethyl)-1-methyl-1H-pyrazol-4-carboxylic acid is low in cost, simple and safe in technological operation, high in product content, and high in product yield; the content is 98.1-98.9% (liquid chromatogram, external standard); the total yield is 52.2-56.9% (based on propargyl alcohol). Nanoscale titanium dioxide is adopted to carry out catalytic esterification, so that the reaction yield is high; the reaction time is short; the used raw materials and solvent are cheap and available; furthermore, an organic solvent is avoided in the four reaction steps, so that the solvent recovery cost and the environmental pollution risk are greatly reduced.

The invention provides a method for preparing ethyl bromodifluoroacetate and relates to a preparation method of a chemical reagent. The method takes trichloro ethylene as a raw material, and comprisesthe following steps: under the action of ultraviolet light of a catalytic medium, an oxidation reaction happens between trichloro ethylene and oxygen in a reactor to synthesize dichloracetyl chloride; an amination reaction happens between dichloracetyl chloride and diethylamine under the action of a catalyst to synthesize dichloroacetyl diethylamine; a fluorination reaction happens between dichloroacetyl diethylamine and anhydrous potassium fluoride under the action of a solvent and a phase transfer catalyst to synthesize difluoroacetyl diethylacetamide; difluoroacetyl diethylacetamide is esterified to synthesize ethyl difluoroacetate; and by taking cupric bromide as a brominating agent, ethyl difluoroacetate is bromized to prepare the end product (ethyl bromodifluoroacetate). The methodhas the characteristics that the equipment investment is low, reaction conditions are mild, the method is safely implemented at normal pressure, and after-treatment is simple.

The invention discloses a resource utilization method of tail gas from trifluoroethylene production. According to the invention, addition reaction between the tail gas from the trifluoroethylene production and bromine is performed to generate dibromotrifluoroethane and dibromotrifluoro chloroethane. The preparation method has the following advantages: the technology is simple; reaction condition is mild; purification is easy; and the technology is suitable for large-scale production. The method provided by the invention has effects of energy conservation and emission reduction. The prepared dibromotrifluoroethane can be used to prepare a dry etching gas hexafluorobutadiene, novel gyroscope suspension fluorobromohydrocarbon oil, alpha, beta, beta-trifluorostyrene and an insecticide and acaricide 1,4-diaryl-2,3-difluoro-2-butene. The prepared dibromotrifluoro chloroethane can be used to prepare a plant growth regulator's intermediate ethyl bromodifluoroacetate and a chain transfer agent used as radical polymerization.

The invention discloses a preparation method of Deracoxib, and belongs to the field of Deracoxib preparation. The preparation method of Deracoxib disclosed by the invention comprises the following steps: (1) taking methane chloride as a reaction solvent, and reacting 2-fluoroanisole with acetylchloride under the effect of acid so as to obtain 3-fluoro-4-methoxyacetophenone; (2) taking methane chloride as a reaction solvent, and reacting 3-fluoro-4-methoxyacetophenone with ethyl difluoroacetate under the effect of alkaline so as to obtain 4,4-difluoro-1-(3-fluoro-4-methoxyphenyl)-1,3-butanedione; and (3) under the existence of an ethyl alcohol solvent, reacting 4,4-difluoro-1-(3-fluoro-4-methoxyphenyl)-1,3-butanedione with para-sulfamine phenylhydrazine or salt thereof so as to obtain Deracoxib. According to the preparation method of Deracoxib disclosed by the invention, dichloromethane is used as a solvent, the toxicity of the solvent is low, the cost of the solvent is lower than thatof methyl tertiary butyl ether, and the production cost is obviously reduced on the premise of guaranteeing the yield.

The invention relates to a fluorine-containing phenanthridine derivative and a preparation method thereof. The structure of the derivative is as shown in the specification. In the structure, R1 is -H, -F or -Cl; R2 is -H or -CH3; and R3 is -H, -CH3 or -OMe. According to the invention, under the condition of silver catalysis, potassium difluoroacetate undergoes decarboxylation and then is coupled with o-phenylisonitrile, so synthesis of a fluorine-containing phenanthridine heterocyclic compound is completed.

The invention relates to a method for preparing chiral alpha- aminobutyric acid with difluorobenzyl methyl function group, especially a method for preparing 4, 4- difluorobenzyl- 2- amino- butyrate and the relative ester. The invention solves problems of dear agent and low productivity in current process. The method comprises following steps: reducing difluorobenzyl acetate to get hemiacetal, catalyzing hemiacetal with organic acid and reacting with ylide phosphorous salt to get difluorobenzyl crotonic ester, hydrolyzing difluorobenzyl crotonic ester under basic condition and getting difluorobenzyl butenoic acid, catalytic hydrogenating difluorobenzyl butenoic acid and getting 4, 4- difluorobenzyl butyrate; directing 4, 4- difluorobenzyl butyrate with Evans ((S)-4- R2- 1, 3- oxygen nitrogen- zole- dione or (R)- 4- R2-1, 3- oxygen nitrogen- zole- dione ) to get chiral azides; hydrogenrating and protecting with amnio said azides and removing directing group from it and getting 4, 4- difluorobenzyl- 2- amino- butyrate of optical-purity; getting relative ester through normal deravitive reaction.

The invention discloses a preparation technique of ethyl difluoroacetate. The preparation technique comprises the following steps: sequentially adding halogenated ethyl difluoroacetate, triethylamine, a solvent and a catalyst into a high-pressure reaction kettle; replacing air in the reaction kettle with nitrogen, replacing with hydrogen, and heating to perform hydrogenation reaction until the kettle pressure reaches the standard value; when the kettle pressure drops, repeatedly introducing hydrogen until the kettle pressure no longer drops; and finally, carrying out rectification reaction, carrying out normal-pressure rectification operation on the obtained product in a glass bottle to separate out the product ethyl difluoroacetate, and carrying out filtration and water washing on the kettle bottom material to recover the catalyst for the reaction next time. By adopting the halogenated ethyl difluoroacetate as the raw material, the preparation technique of ethyl difluoroacetate has the advantages of simple preparation process, high product purity (at least 99.5%) and high yield (at least 95%), and the catalytic efficiency of the palladium-carbon catalyst does not obviously descend after the palladium-carbon catalyst is recovered 10 times, thereby enhancing the benefits of the enterprise.

The invention relates to a method for preparing difluoroacetic acid and the salts thereof. The invention also relates to the preparation of difluoroacetyl fluoride used as an intermediate product in the preparation of difluoroacetic acid. The method for preparing difluoroacetic acid according to the invention is characterized in that the same comprises the step of preparing difluoroacetyl fluoride by reacting dichloroacetyl chloride with hydrofluoric acid in a gaseous phase and in the presence of a chromium-based catalyst, followed by the step of hydrolysing the difluoroacetyl fluoride thus obtained.

The invention relates to a method for catalytically hydrogenating difluoroacetic acid. The new method includes the following steps: step 1: preparation of catalyst: sodium borohydride as catalyst is added into organic solvent solution; step2: implementation of main reaction: the organic solvent with the sodium borohydride is added into a reaction kettle, the reaction kettle is sealed, temperature is increased, the difluoroacetic acid is added, and after sufficient reaction, the temperature is kept; step 3: extraction and rectification of product: the reaction product in step 2 is added with 300ml of water, the organic solvent is recovered by distillation, hydrochloric acid is used for regulating the pH value to 2 to 3, sodium bicarbonate solution is then used for regulating the pH value to 10, and after filtration and drying, product is obtained.

The invention relates to a novel synthesis method for forming superacid functional molecules that include monomers, as well as new polymers and copolymers formed from the monomers, and uses for these superacid molecules, polymers, and copolymers. The superacid molecules have an alpha,alpha-difluorosulfonic acid functionality that can be obtained by a reaction between various Grignard reagents and an alkyl(2-fluorosulfonyl)-1,1-difluoroacetate, such as methyl(2-fluorosulfonyl-1,1-difluoroacetate. The molecules, polymers and copolymers would be expected to have enhanced ion conductivity, and would be useful in a variety of applications, including as ion-conductive materials, surfactants, and ion exchange resins.

The invention relates to a synthesizing method, in particular to a synthesizing method for ethyl difluoroacetate, and aims at solving the problems that an existing synthesizing method for the ethyl difluoroacetate is complex in technological process, low in safety and high in preparation cost. The synthesizing method comprises the steps that 1, a catalyst is prepared, wherein a tubular reactor is filled with Al2O3 powder with the certain particle size meshes, it is guaranteed that the height of the Al2O3 powder is in a heating area of the tubular furnace, the temperature is increased to 250 DEG C-300 DEG C under nitrogen protection and kept for 12 h, CHaFbClc gas is continuously and slowly introduced for a reaction, the reaction temperature is set at 250 DEG C-300 DEG C, and the reaction time is set for 12 h; 2, 1,1,2,2-tetrafluoroethyl ethylether is taken as raw materials for a reaction under the conditions of the certain temperature and the catalyst, and an intermediate does not need to be separated and is directly collected through condenser to be converted into ethyl ester. The method belongs to the field of chemical engineering.

The invention discloses a method for preparing ethyl 4,4-difluoroacetoacetate. The method comprises the following step: by taking ethyl difluoroacetate and ethyl acetate as raw materials, and an ethanol solution of sodium ethoxide as a catalyst, in the presence of an organic solvent, carrying out a Claisen condensation reaction, thereby obtaining the ethyl 4,4-difluoroacetoacetate. The method disclosed by the invention has the characteristics of being gentle in reaction condition, high in security, good in reaction selectivity, easy in product separation and purification, applicable to industrial production, and the like.

The invention discloses a synthesis method for an anti-tumor new medicine 3-{(3-chlorphenyl)difluoromethyl-1-isopropyl-monohydro-pyrazolo(3,4-D)pyrimidine-4-amine compound. The synthesis method comprises the following steps of: acylating 3-chlorphenyl-2 oxalic acid serving as an initiative raw material; reacting the acylated material with dipropionitrile; performing methylation; performing ring closure with hydrazine hydrate to obtain 5-amino-1-(3-chlorophenyl)-pyrazole-4-carbonitrile, crystallizing and purifying, heating and performing ring closure with formamide to obtain a target mother ring; performing fluorination on carbonyl by using DAST; introducing difluorine into an active group so as to improve the bioactivity of the compound; performing process optimization on the basis of the compound; and performing the similar steps by using 2-(3-chlorphenyl)-2,2-difluoroacetic acid as a raw material to obtain the target product.

Disclosed is a method for producing a difluoroacetic acid ester which involves at least: a reaction step in which a reaction solution is obtained by bring an alcohol represented by ROH into contact with a difluoroacetic acid fluoride (CHF2COF) in the presence of a hydrogen fluoride scavenger comprising an amide compound represented by formula (1) or a sulfone compound represented by formula (2); and a distillation step (A) in which a difluoroacetic acid ester represented by CHF2COOR is obtained as a distillate from the reaction solution obtained in the reaction step. As a consequence, said production method does not cause a drop in product yield attributable to hydrogen fluoride, which is a by-product of the mechanism of esterification reaction using difluoroacetic acid fluoride.

The invention relates to the field of organic synthesis, in particular to a preparation method of 1-difluoroalkyl isoquinoline. The method comprises the following steps: taking alkenyl isocyanide and a difluoroacetic acid derivative as raw materials, taking palladium chloride as a catalyst, taking organic phosphine as a ligand and taking inorganic salt as alkali in a polar solvent under protection of inert gas; fully stirring at a certain temperature; after reaction reaches an end point, separating and purifying to obtain the 1-difluoroalkyl isoquinoline. The method not only is gentle in reaction condition, high in operability, low in cost, high in safety and environment-friendly, but also is high in reaction conversion percent, high in yield and short in technological process; the reaction scale is easy to expand; and therefore, the preparation method of the 1-difluoroalkyl isoquinoline has the advantage of suitability for industrial production.