667-27-6Relevant academic research and scientific papers
Preparation process of ethyl difluorobromoacetate
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Paragraph 0031-0075, (2021/08/07)
The invention relates to the field of preparation of organic chemistry, in particular to a preparation process of ethyl difluorobromoacetate. According to the preparation process, ethanol is used as a solvent and azodiisobutyronitrile is used as a catalyst in a reaction, 1-chloro-1,2-dibromo-1,2,2-trifluoroethane is used as a raw material, and an oxidation reaction is conducted on the above materials under the conditions of constant temperature and constant pressure according to a certain ratio of the materials so as to prepare a finished product, namely ethyl difluorobromoacetate; and thus a corrosive solvent is not needed in the synthesis of ethyl difluorobromoacetate, corrosive gas is avoided, and the method is more environment-friendly and safer.
Acridine Orange Hemi(Zinc Chloride) Salt as a Lewis Acid-Photoredox Hybrid Catalyst for the Generation of α-Carbonyl Radicals
Das, Sanju,De Sarkar, Suman,Mandal, Tanumoy
supporting information, (2021/12/10)
A readily accessible organic-inorganic hybrid catalyst is reported for the reductive fragmentation of α-halocarbonyl compounds. The robust hybrid catalyst is a self-stabilizing combination of ZnCl2 Lewis acid and acridine orange as the photoactive organic dye. Mechanistic specifics of this hybrid catalyst have been studied in detail using both photophysical and electrochemical experiments. A systematic study enabled the discovery of the appropriate Lewis acid for the effective LUMO stabilization of α-halocarbonyl compounds and thereby lowering of reduction potential within the range of a standard organic dye. This strategy resolves the issues like dehalogenative hydrogenation or homo-coupling of alkyl radicals by guiding the photoredox cycle through an oxidative quenching pathway. The cooperativity between the photoactive organic dye and the Lewis acid counterparts empowers functionalization with a wide range of coupling partners through efficient and controlled generation of alkyl radicals and serves as an appropriate alternative to the expensive late transition metal-based photocatalysts. To demonstrate the application potential of this cooperative catalytic system, four different synthetic transformations of α-carbonyl bromides were explored with broad substrate scopes.
Method for preparing ethyl difluorobromoacetate
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Paragraph 0031; 0034; 0037; 0039; 0041; 0043; 0045; 0047, (2021/06/22)
The invention discloses a method for preparing ethyl difluorobromoacetate, which comprises the following steps: by taking CF2Cl-CH2Cl as a raw material, firstly removing HCl to obtain CF2 = CHCl, then carrying out addition on the CF2 = CHCl and bromine to obtain CF2Br-CHClBr, then reacting the CF2Br-CHClBr with oxygen and a photoinitiator under the photocatalysis to obtain CF2Br-COCl, and finally carrying out esterification reaction on the CF2Br-COCl and ethanol to obtain the ethyl difluorobromoacetate. According to the method, a photooxidation reaction process is adopted in the CF2Br-COCl preparation process, the conversion rate of CF2Br-CHClBr and the selectivity of CF2Br-COCl are very high, meanwhile, the use of strong-corrosivity concentrated sulfuric acid or a sulfur trioxide oxidizing agent or a mercury-containing high-toxicity catalyst is avoided, and the process is green and environmentally friendly.
Photo-triggered self-catalyzed fluoroalkylation/cyclization of unactivated alkenes: Synthesis of quinazolinones containing the CF2R group
Yang, Jin,Sun, Bin,Ding, Hao,Huang, Pan-Yi,Tang, Xiao-Li,Shi, Rong-Cheng,Yan, Zhi-Yang,Yu, Chuan-Ming,Jin, Can
supporting information, p. 575 - 581 (2021/01/28)
A novel photo-triggered self-catalyzed fluoroalkylation/cyclization of quinazolinones containing unactivated alkenes with various fluoroalkyl bromides has been developed. This transformation exhibits excellent substrate generality with respect to both the coupling partners. Of note is that this is the first example describing the Csp3-Br bond homolysis of alkyl bromides via a substrate (quinazolinones) induced energy transfer process. Additionally, the mild conditions, tolerance to a wide range of functional groups and operational simplicity make this protocol practical for the synthesis of fluorine-containing ring-fused quinazolinones. This journal is
Production process of ethyl bromodifluoroacetate
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Paragraph 0026-0027, (2020/12/30)
The invention discloses a production process of ethyl bromodifluoroacetate. The production process comprises the following steps: 1, bromination reaction; 2, elimination reaction; 3, oxidation reaction; 4, esterification reaction. Compared with other methods, the bromination addition reaction only needs to be carried out at normal pressure and under the catalysis of infrared light, so that the cost is saved compared with other catalysts, other impurities are not introduced, and the utilization rate of bromine is increased. The elimination reaction adopts a dropwise adding mode, so the reactionrate can be effectively controlled, and the flooding phenomenon which is easy to generate is avoided. The purity of the prepared finished product is greater than or equal to 99.0%, and the yield is greater than or equal to 80.0%.
A two-fluorine bromine acetate preparation method (by machine translation)
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Paragraph 0021; 0025; 0031; 0035; 0036; 0040, (2019/01/22)
The invention provides a two-fluorine bromine acetate preparation method, comprises the following steps: (1) in order to CF2 X - CHCl2 As raw materials, through the dehydrochlorination cancels out the reaction, bromine addition reaction CF2 Br - CClXBr, wherein X is H or Cl; (2) step (1) in the CF2 Br - CClXBr optical oxidation or with sulfur trioxide oxidation reaction, reaction to obtain the CF2 Br - COCl; (3) the step (2) in the CF2 Br - COCl alcohol in the esterification reaction, after separation, distillation, thus obtaining the product 2, 2 - difluoro - 2 - [...] ester. The invention two fluorine bromine acetate preparation method, so that the 1, 1 - difluoro - 2, 2 - dichloroethane or 1, 1 - difluoro - 1, 2, 2 - trichloroethane two by-product that is utilized, reduce their pollution of the environment, but also the production two fluorine bromines acetate process is environment-friendly, two fluorine bromines acetate yield and safety are relatively high. (by machine translation)
Method for preparing ethyl bromodifluoroacetate
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Paragraph 0028, (2018/04/02)
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.
Green synthesis method of ethyl bromodifluoroacetate
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Paragraph 0009; 0019-0023; 0025, (2018/03/01)
The invention provides a green synthesis method of ethyl bromodifluoroacetate. According to the method, 1,1-difluoro-1,2-dichloroethane is used as a starting material; elimination reaction is performed to obtain 1,1-difluoro-2-chloroethylene; the 1,1-difluoro-2-chloroethylene and bromine are subjected to addition to obtain 1,1-difluoro-1,2-dibromo-2-chloroethane; then, the elimination reaction is performed to obtain a 1,1-difluoro-2-bromine-2-chloroethylene; then, the 1,1-difluoro-2-bromine-2-chloroethylene and the bromine are subjected to addition to obtain 1,1-difluoro-1,2,2-tribromo-2-chloroethane; then, sulfur trioxide is used for oxidizing the 1,1-difluoro-1,2,2-tribromo-2-chloroethane; 1,1-difluoro-1-bromoacetyl chloride is obtained; finally, the 1,1-difluoro-1-bromoacetyl chloride and ethyl alcohol are esterified to obtain 2,2-difluoro-2-ethyl bromoacetate. The synthesis method has the advantages that the problems of recovery and utilization of waste materials of 1,1-difluoro-1,2-dichloroethane (R132b) are solved; no organic solvents are used in the reaction process; the oxidation step uses SO3 for oxidation; high temperature and high pressure or concentrated sulfuric acid is not needed; the safety is enhanced; the discharging of waste acid is reduced; the green production requirement is met; the product yield is relatively high; the green synthesis method is suitable for industrial production.
Preparation method of ethyl bromodifluoroacetate
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Paragraph 0054-0057; 0059-0060; 0062-0063; 0065-0066, (2017/08/27)
The invention belongs to the field of organic synthesis and discloses a preparation method of ethyl bromodifluoroacetate. Difluorobromoacetonitrile is taken as a raw material, and prepared through a one-pot method and subjected to alcoholysis and esterification in ethanol aqueous solution to obtain ethyl bromodifluoroacetate. According to the method provided by the invention, difluorobromoacetonitrile is taken as the raw material and then bromodifluoroacetic acid is subjected to the alcoholysis and esterification after directly hydrolyzed, without generating a toxic bromodifluoroacetyl halide intermediate, and the use of fuming sulfuric acid as an oxidant and bad in operating environments and maximum in pollution, or peroxide or ozone, or oxygen in a high pressure system to result in poor selectivity and very low yield is avoided. Furthermore, the existence of by-products with extremely strong hydrogen halide corrosion of hydrogen fluoride and the like which both have extremely large corrosion to metal and glass-lined materials is avoided in the process, so that the requirements for production reaction equipment are lowered, and the preparation of ethyl bromodifluoroacetate can be carried out in the ordinary glass-lined reaction device.
Ozone oxidation process of preparing a halogenated acetic acid and esters thereof (by machine translation)
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Paragraph 0080-0082, (2017/06/29)
The invention belongs to the field of chemical synthesis, in particular to a halogenated acetic acid or a halogenated acetic acid ester compound preparation method; halogenated ethane (type I) by ozone oxidation after the reaction, the reaction with water or alcohol to obtain a halogenated acetic acid or halogenated acetate (type II). (by machine translation)
