Aq. poly:enyl-tri:aryl-phosphonium salt soln. prodn. - by steam stripping of organic solns

Prodn. of aq. solns. of polyenyltriarylphosphonium salts of formula R-P(Ar)3 +X- (I) (where R is a 5-20C aliphatic, cycloaliphatic-aliphatic or aromatic-aliphatic polyene radical; Ar is aryl; X- is the anion equiv. of a strong acid) is carried out by steam stripping a 10-70 wt.% soln. of (I) in an organic solvent, maintained at 30-120 degrees C, so that the solvent and any other volatile cpds. derived from the synthesis of (I) are removed and part of the steam condenses to form an aq. soln. Some cpds. (I), e.g. (I; R is beta-ionylidenethyl) are useful as pesticides (e.g. for control of water snails); others are useful as intermediates for carotenoid synthesis (cf. DT 2505869). The process avoids thermal decompsn. (cf. direct distn.) and foaming (cf. addn. of water followed by distn.).