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 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 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 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 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.