- Preparation method of ethyl 4-chloroacetoacetate
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The invention discloses a preparation method of ethyl 4-chloroacetoacetate, which specifically comprises the following steps of: (1) chlorination: cooling dichloromethane for the first time, then adding acetyl ketene for cooling for the second time, then introducing chlorine gas, and keeping the temperature; (2) esterification: dropwise adding absolute ethyl alcohol, and keeping the temperature; (3) desolvation and deacidification: heating and distilling to remove dichloromethane and hydrogen chloride; and (4) rectification: rectifying and purifying to obtain the product. Acetyl ketene is used as a raw material, the raw material is low in cost and easy to obtain, the synthesis steps are simple, and the production cost is reduced; by optimizing the ratio of process materials, the selectivity of the product ethyl 4-chloroacetoacetate is improved, and the yield is increased; and through high-vacuum low-temperature distillation, the decomposition of the heat-sensitive product ethyl 4-chloroacetoacetate is effectively prevented, and the yield and the product quality are improved.
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Paragraph 0041; 0045-0051; 0055-0061; 0065-0070
(2021/08/06)
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- Continuous device and method for industrial production 4 - chloroacetoacetate
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The invention relates to an industrial production 4 - chloroacetoacetate continuous device and a method. The device and method can inhibit the generation of byproduct 2 - chloroacetoacetate and 4 - chloroacetoacetate in 2 - chloroacetoacetate crude product can be controlled below 0.15%. The yield of 4 - chloroacetoacetate can be improved, and the yield 4 - chloroacetoacetate can reach 97% or more. The continuous device and the method provided by the invention can be operated continuously, 4 - chloroacetoacetate can be industrially produced, and the continuous device has remarkable economic value.
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Paragraph 0024; 0040-0041; 0042-0043; 0044-0045; 0046-0047
(2021/11/06)
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- Synthetic method for ethyl 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate
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The invention discloses a synthetic method for ethyl 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate. The method is characterized by comprising the following steps: a, performing chlorination on diketene, and performing alcoholysis to synthesize ethyl 4-chloroacetoacetate; b, performing oximation on the ethyl 4-chloroacetoacetate to synthesize ethyl 4-chloro-2-(hydroxyimino)-3-oxobutanoate; c, performing a reaction on the ethyl 4-chloro-2-(hydroxyimino)-3-oxobutanoate and thiourea to synthesize ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate; and d, performing hydrocarbonylation on the ethyl2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate to synthesize the ethyl 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate. The method has the following advantages: 1, the chlorination reaction in the stepa is a continuous reaction, and has a fast reaction speed and no accumulation of a large amount of dangerous materials, so that the danger is small; 2, the costs of equipment are lower, the equipmentis conventional organic synthesis equipment, no expensive and special equipment is needed, so that the equipment is easy to copy, and the production efficiency is improved; and 3, the diketene is directly used as a raw material, the raw material cost is low, the synthetic steps are simple to operate, so that the method facilitates reducing the production costs of the ethyl 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate.
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Paragraph 0016
(2020/01/12)
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- Method for preparing 4-chloracetylethyl acetoacetate
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The invention relates to a method for preparing 4-chloracetylethyl acetoacetate. The method comprises the steps: adding ketene dimer into a dichloromethane (DCM) solvent with a temperature of -40 DEGC to -20 DEG C, adding alkaline substances, carrying out uniform stirring, keeping a temperature of a solution system to be -40 DEG C to -20 DEG C, and introducing chlorine gas into the solution withstirring; and after the reaction is completed, adjusting the temperature of the solution to be -40 DEG C to -10 DEG C, dropwise adding ethanol into the solution, carrying out stirring until the reaction is full, and subjecting a product to distillation and rectification, thereby obtaining a target product, i.e., the 4-chloracetylethyl acetoacetate. According to the preparation method disclosed bythe invention, the proportion of a product 1 in a chlorination reaction can be increased, and then, the yield of the final 4-chloracetylethyl acetoacetate is increased.
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Paragraph 0023; 0024; 0025; 0028; 0029
(2019/05/15)
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- Method for synthesizing oxiracetam intermediate 4-ethyl chloroacetoacetate
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The invention discloses a method for synthesizing oxiracetam intermediate 4-ethyl chloroacetoacetate and belongs to the field of pharmacy. The method is characterized in that chloroacetate and ethyl acetate react under the action of a catalyst to obtain the 4-ethyl chloroacetoacetate. The reaction process is: (1) evenly mixing the ethyl acetate, the catalyst and a solvent A, introducing protectivegas, controlling the pressure to be 0.3-0.5 Mpa, controlling the temperature to be 110-135 DEG C, adding a solution prepared from chloroacetate and a solvent B dropwise, controlling the addition timeto be 15-25 min, after chloroacetate and the solvent B are added, increasing the reaction temperature to 145-160 DEG C, increasing the pressure to 0.8-1 Mpa, continuing the reaction for 15-25 h, andthen ending the reaction; and (2) after a system is cooled, filtering the system to remove solid, adding filtrate to water with the volume being 3-5 times that of the filtrate, using a solvent C for extraction, and after an extract is dried with a drying agent, concentrating and evaporating the solvents to obtain a product. The method for synthesizing the oxiracetam intermediate 4-ethyl chloroacetoacetate has the advantages of relatively short steps, low process cost and few side effects.
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Paragraph 0035-0040
(2019/03/28)
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- Efficient α-chlorination of carbonyl containing compounds under basic conditions using methyl chlorosulfate
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An efficient method for the α-chlorination of ketones under basic conditions is described using methyl chlorosulfate. Its applicability for the chlorination of other functional groups has also been studied and it is equally useful for the synthesis of α-chloroesters and amides. Methyl chlorosulfate is described for the first time as a positive chlorine source. Some aldol reactions which occur during the chlorination of some substrates are also reported.
- Silva, Saúl,Maycock, Christopher D.
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supporting information
p. 1233 - 1238
(2018/02/27)
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- A 4-chloro-acetyl-acetic acid ethyl ester preparation method
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The invention relates to a preparation method of 4-chloracetyl ethyl acetate. The preparation method comprises the following steps: by taking diketene as an initial raw material, synthesizing a 4-chloracetyl ethyl acetate coarse product in two steps: chlorination and esterification; then, rectifying to obtain a finished product, and adding a stabilizer anhydrous cupric sulfate into the chlorination step, wherein the addition is 0.02-1wt% of diketene. Compared with the prior art, the preparation method provided by the invention has the advantages that 1, by adding the stabilizer anhydrous cupric sulfate, the production of a byproduct 2-chloracetyl ethyl acetate is reduced and the production of the byproduct 2-chloracetyl ethyl acetate in the 4-chloracetyl ethyl acetate coarse product can be controlled below 0.5%, so that the distill yield is greatly improved; 2, the yield of 2-chloracetyl ethyl acetate is over 94.5%, and the cost is greatly lowered.
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Paragraph 0026
(2016/10/09)
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- Process for the production of 4-chloroacetyl chloride, 4-chloroacetic acid esters, amides and imides
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The invention relates to process for the continuous production of 4-chloroacetoacetyl chloride, comprising the steps of (a) feeding diketene and chlorine into a thin film reactor and (b) reacting the diketene and chlorine to obtain 4-chloroacetoacetyl chloride. The invention also relates to a process for the production of 4-chloroacetic acid ester, 4-chloroacetic acid amide or 4-chloroacetic acid imide from 4-chloroacetoacetyl chloride obtained according to the inventive process.
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Page/Page column 10; 11
(2012/11/13)
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- Reactions of diethyl dibromomalonate and ethyl 2,2-dichloroacetoacetate with water and carbonyl compounds (aldehydes and ketones) in the presence of pentacarbonyliron
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Diethyl dibromomalonate and ethyl 2,2-dichloroacetoacetate are effectively reduced with the system pentacarbonyliron-proton-donor compound (water or butyl methyl ketone) to give the corresponding hydrodehalogenation products. These results provide a support for the previous assumption that the key reaction stage is reduction with pentacarbonyliron of initially formed radical to anion which is then involved in proton transfer.
- Terent'ev,Vasil'eva,Mysova,Chakhovskaya
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p. 924 - 927
(2007/10/03)
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- Method for preparing chiral diphosphines
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The invention concerns a method for preparing a compound of formula (1) wherein: A represents naphthyl or phenyl optionally substituted; and Ar1, Ar2independently represent a saturated or aromatic carbocyclic group, optionally substituted.
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- Preparation of fluorinated dicarbonyls
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PCT No. PCT/GB94/02547 Sec. 371 Date Feb. 21, 1997 Sec. 102(e) Date Feb. 21, 1997 PCT Filed Nov. 18, 1994 PCT Pub. No. WO95/14646 PCT Pub. Date Jun. 1, 1995A method for the fluorination of 1,3-diketones and 1,3-ketoesters is disclosed.
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- Asymmetric hydrogenation method of a ketonic compound and derivative
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The present invention relates to a process for the asymmetric hydrogenation of a ketonic compound and derivative. The invention relates to the use of optically active metal complexes as catalysts for the asymmetric hydrogenation of a ketonic compound and derivative. The process for the asymmetric hydrogenation of a ketonic compound and derivative is characterized in that the asymmetric hydrogenation of said compound is carried out in the presence of an effective amount of a metal complex comprising as ligand an optically active diphosphine corresponding to one of the following formulae: STR1
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- Thiazole derivatives
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Compounds of formula I STR1 as well as pharmaceutically usable salts and esters thereof, wherein R1, R2 and R3 have the significance given in claim 1, inhibit the binding of adhesive proteins to the surface of different types of cell and accordingly influence cell-cell and cell-matrix interactions. They can be used in the form of pharmaceutical preparations in the control or prevention of neoplasms, tumor metastasing, osteoporosis, Paget's disease, diabetic retinopathy, macular degeneration, restenosis following vascular intervention, psoriasis, arthritis, kidney failure as well as infections caused by viruses, bacteria or fungi.
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- Combating arthropods with 3-alkoxymethyl- and-alkylthiomethyl-pyrazol(5)yl(thiono)(thiol)-phosphoric(phosphonic) acid esters and ester-amides
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3-Alkoxymethyl- and -alkylthiomethyl-pyrazol(5)yl(thiono)(thiol)-phosphoric(phosphonic) acid esters and ester-amides of the formula STR1 in which R is hydrogen, alkyl, cyanoalkyl or phenyl, R1 is hydrogen or halogen, R2 is alkoxy or alkylthio, R3 is alkyl, alkoxy, monoalkylamino or phenyl, R4 is alkyl, and X and Y each independently is oxygen or sulphur, which possess arthropodicidal properties.
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- Combating arthropods with N,N-dimethyl-O-[3-(substituted-methyl)-pyrazol-5-yl]-carbamic acid esters
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N,N-Dimethyl-O-[3-(substituted-methyl)-pyrazol-5-yl]-carbamic acid esters of the formula STR1 in which R is hydrogen, alkyl, cyanoalkyl or phenyl, and R1 is alkoxy or alkylthio which possess arthropodicidal properties.
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