Fluorinated styrene prodn. - from fluorinated benzyl-tri:phenyl-phosphonium halide and para-formaldehyde

摘要

Prodn of fluorinated styrene derivs of formula (I) is carried out by reacting 1 mole of a fluorinated benzyl- triphenylphosphonium halide of formula (II) with 2-10 moles of paraformaldehyde (III) at 0-100 deg C in an aq medium contg 1-10 equivs of a strong bases. (where X is Cl or Br; R1-R3 are F or partially or totally fluorinated alkyl or alkoxy, and R2 and R3 can also be H). (I) can be homo- or copolymerised (e.g. with styrene or acrylate esters) to produce polymers with unique optical properties, e.g. low refractive index and high dispersion (low abbe no). The use of (III) rather than aq. formalin reduces the vol of the reaction mixt and increases space-time yields.