Quaternary pyridinium ketoximes - New efficient micellar hydrolytic catalysts

A series of quaternized alkyl pyridyl ketoximes was synthesized and tested as micellar hydrolytic catalysts. 2- And 4-[1-(hydroxyimino)tridecyl]-1-met hylpyridinium bromides were surprisingly efficient, most probably due to th e location of their nucleophilic hydroxyimino group below the micellar surf ace. Absorbance of the reaction mixture vs time plots exhibited remarkable positive deviation from the first-order kinetics when hydrolysis of 4-nitro phenyl phosphates was catalyzed by 1-dodecyl-3-[1-(hydroxyimino)ethyl]- or 3-[1-(hydroxyimino)tridecyl]-1-methylpyridinium bromide.