| 摘要 |
<p>Aliphatic perfluoroketones (I) are prepd. by reacting a perfluorocarboxylic acid salt R1-CO2M (II) with a perfluoroacyl fluoride R2-CO-F (III) in a polar aprotic solvent at 20-200 degrees C. In the formulae M is Li, Na, K, Rb, Cs or Ag; R1 is 2-50C perfluoroalkyl opt. contg. ether-O-function(s) R2 is 1-50C perfluoroalkyl opt. contg. ether-O-function(s). (II) may be prepd. from R1COF and a salt of formic or oxalic acid or of a Gp. IIIA to VIIA element oxyacid which is less strong than CF3CO2H, esp. M2CO3. Prepn. is in a polar aprotic solvent at 20-200 degrees C. Alternatively a mixt. of (II) and (III) may be prepd. from (R1CO)2O and an alkali metal fluoride. Perfluorolefins (which are difficult to obtain) are not used. High boiling (I) may be prepd. (I) are inert to acids, oxidants and heat. They may be used as heat transfer media or lubricants. In an example perfluoro-2,4-bis-(3,6-dimethyl-1,4-dioxanyl-2-oxylpentan-3-one was prepd. from potassium perfluoro- alpha-(3,6-dimethyl-1,4-dioxanyl-2-oxylpropionate and the corresp. perfluoroacyl fluoride in tetraglyme.</p> |
