- Green synthesis method of ethyl bromodifluoroacetate
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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.
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Paragraph 0009; 0019; 0021; 0023; 0025
(2018/03/01)
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- Halogenated diazirines as photolabel mimics of the inhaled haloalkane anesthetics
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The inhaled anesthetics are low affinity volatile compounds whose mechanism of action remains unclear, in part due to the difficulty of determining their binding targets. Photolabeling may help resolve this difficulty, and thus we have synthesized six compounds (four previously unreported) with structural and physical similarity to halothane (1-bromo-1-chloro-2,2,2-trifluoroethane), a commonly used clinical anesthetic. These compounds incorporate either a diazo, diazirine, or azido group to provide photolability in the long-UV range and to provide a highly reactive photolysis product. While several of the compounds have immobilizing activity in tadpoles, it is complicated by either toxicity or very low potency. One compound however, a halogenated three-carbon diazirine 4, is a potent anesthetic, is apparently nontoxic, potentiates GABAA Cl- currents, and stabilizes serum albumin, all of which are features of halothane. When tagged with radioactivity, this compound should serve as a reasonable probe of haloalkane anesthetic binding targets and sites.
- Eckenhoff, Roderic G.,Knoll, Frank J.,Greenblatt, Eric P.,Dailey, William P.
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p. 1879 - 1886
(2007/10/03)
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- Practical preparation of potentially anesthetic fluorinated ethyl methyl ethers by means of bromine trifluoride and other methods
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Synthetic methods, especially those that use bromine trifluoride as a fluorinating agent, are described for the preparation of a number of fluorinated ethyl methyl ethers in good yield and high purity. In all cases, medium-scale syntheses (8-22g) of potentially anesthetic compounds have been accomplished. The compounds are of sufficient purity (>99%) for biological evaluation.
- Hudlicky, Tomas,Duan, Caiming,Reed, Josephine W.,Yan, Fengyang,Hudlicky, Milos,Endoma, Mary Ann,Eger II, Edmond I.
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p. 363 - 367
(2007/10/03)
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- Synthesis of Mercapturic Acids Related to the Metabolism of Halothane
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Mercapturic acid derivatives corresponding to possible or actual metabolites of the anaesthetic halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) were synthesized by the reaction of N-acetyl-L-cysteine with 2-bromo-2-chloro-1,1-difluoroethene, 2-chloro-1,1-difluoroethene, and 2-bromo-1,1-difluoroethene.Saturated conjugates of the type RSCF2CHXY were formed by nucleophilic addition of the thiolate anion when the reaction was carried out in aqueous methanol containing sodium hydroxide.Unsaturated conjugates of the type RSCF=CHX, corresponding to displacement of fluorine, were the major products from the latter two alkenes under anhydrous aprotic conditions using N,N-dimethylformamide and triethylamine.Structure assignments of the conjugates are based mainly on 1H and 13C n.m.r. data.
- Sachdev, Krishna G.,Cohen, Ellis N.,Cheung, H. T. Andrew,Chau, Dieu D.
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p. 2868 - 2883
(2007/10/02)
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