- Synthese des α,ω-dichlorures d'acide a chaines chlorofluorees par hydrolyse des α,ω-bis trichloromethyles correspondants
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This paper describes the transformation of α,ω-bis(trichloromethyl) compounds into perhalogenated diacid chlorides.The general formulae of the starting products are CCl3-(CF2-CFCl)x-CF2-CCl3 (I,x) with x=0, 1, 2 and CCl3-CF2-CCl2-CF2-CCl3 (II).Hydrolysis, by oleum, of compounds (I,0) and (I, 2) leads to the corresponding diacid chlorides.Hydrolysis of (I, 1) and (II) however yields perhalogenated cyclic, sixmembered stable acid anhydrides.In the second part of this work, several methods are compared for synthesizing diacid chlorides from diacids or cyclic anhydride s prepared by the hydrolysis of (I, 1) and (II).We have found that of these the most interesting is the reaction between a perhalogenated diacid with 1,4-bis(trichloromethyl)benzene.The perhalogenated diacid chlorides are prepared with a minimum yield of 50percent.
- Boutevin, B.,Rasoloarijao, L. Ranjalahy,Rousseau, A.
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p. 153 - 164
(2007/10/02)
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The acrylic ester F2CCFCO2CD3 is prepared from a mixture of difluorotetrachloroethanes CFCI2CFCI2 and CF2CICCI. The dehalogenation of these Freons, followed by the addition of CFCI3 by means of AICI3 leads to a mixture of chlorofluoropropanes. The hydrolysis with oleum gives the acid chlorides which are then esterified by CD3OD. The dehalogenation of the mixture by the zinc stirred in oxalic acid enables isolation of the expected ester by distillation. This compound, the refractive index of which n20D=1.3667 does not show a major absorption in the near infra-red between 0.6 and 1.4 μm. Thus the corresponding polymer is likely to provide a good material for the core of optical fibers.
- Boutevin,Pietrasanta,Rousseau,Bosc
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p. 151 - 169
(2007/10/02)
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