- Preparation method of hexafluoro-1,3-butadiene and intermediate thereof
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The invention discloses a preparation method of hexafluoro-1,3-butadiene and an intermediate thereof, wherein the preparation method of hexafluoro-1,3-butadiene comprises the steps: A1, carrying out areaction on 1,2-dibromo-1-chloro-1,2,2-trifluoroethane with trifluorohaloethylene in a polar aprotic solvent under the action of an initiator, and rectifying and purifying a reaction solution to obtain 1,4-dibromo-2-chloro-3-halo-1,1,2,3,4,4-hexafluorobutane, wherein the structural formula of trifluorohaloethylene is CF2=CFX, X is Cl, Br or I, and the initiator is selected from at least one of azodiisobutyronitrile, di-tert-butyl peroxide, dibenzoyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, potassium persulfate and ammonium persulfate; and A2, carrying out dehalogenation reactionon 1,4-dibromo-2-chloro-3-halo-1,1,2,3,4,4-hexafluorobutane and zinc powder to obtain hexafluoro-1,3-butadiene. The preparation method has the advantages of simple process, mild reaction conditions, suitability for industrial production and the like.
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Paragraph 0042; 0044-0046; 0050-0072; 0094-0099
(2020/09/30)
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- ADDITION OF 1,2-DIBROMO-1-CHLOROTRIFLUOROETHANE TO CHLOROTRIFLUOROETHYLENE INDUCED BY UV-RADIATION. SYNTHESIS OF PERFLUORO-1,3-BUTADIENE AND PERFLUORO-1,3,5-HEXATRIENE
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Photochemically initiated reaction of 1,2-dibromo-1-chlorotrifluoroethane (II) with chlorotrifluoroethylene (I) gave 38percent 1,4-dibromo-2,3-dichlorohexafluorobutane (III) and 19percent 1,6-dibromo-2,3,5-trichlorononafluorohexane (IV) in addition to the higher telomers.Dehalogenations of III and IV yielded perfluoro-1,3-butadiene (VI) and perfluoro-1,3,5-hexatriene (VIII) with 3-chlorononafluoro-1,5-hexadiene (VII), respectively.Photochemical reduction of butane III with 2-propanol resulted in a preferential reduction of C-Br bonds, and from 2,3-dichloro-1,1,2,3,4,4-hexafluorobutane (IX) thus formed, esters of difluoroacetic acid were prepared by dehalogenation of IX and subsequent oxidation and esterification of the product.The photochemical reduction of hexane IV gave a mixture of 79percent trichlorononafluorohexane XII and 21percent dichlorononafluorohexane XIII.The mechanism of formation of the unusual products of the title addition reaction is discussed.
- Dedek, V.,Chvatal, Z.
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p. 363 - 380
(2007/10/02)
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