Quat. phosphonium halides prodn. - from alkyl halide and phosphine or its prim., sec. or tert. alkyl derivs. over catalyst

摘要

Prodn. of quat. phosphonium halides (I) of formula (R1R2R3R4P)X (in which R1-4 are opt. different alkyl gps.; X is halogen, esp. Br or Cl) comprises (a) passing a phosphine (II) of formula PH3, R1PH2, R1R2PH or R1R2R3P and an alkyl halide (III) of formula R4X in 0.02-10, pref. 0.05-2 molar ratio over a catalyst at 100-500, pref. 150-350 degrees C and up to 10 at. g., pref. normal pressure, so that the dwell time is 0.5-500, pref. 10-200 s; and (b) sepg. (I) from the reaction gases. Active C or opt. supported finely-divided gp. Ib or gp. VIII metals can be used as the catalyst. (I) are intermediates for flame retardants, extractants etc. The process uses readily available starting materials. Unlike conventional processes, it is not confined to the use of tert. phosphines, which are very costly to produce.