Separation Science and Technology, Vol.41, No.5, 887-908, 2006
Adsorptive separation of o-/p-aminoacetophenones using acidic ion exchange resins
Separation of o-/p-aminoacetophenones (o-/p-AAPs) is investigated by a two-step process: selective solubilization in an organic solvent followed by reactive adsorption on functionalized polymers. Since, p-AAP and o-AAP show inter- and intra-molecular hydrogen bonding, respectively, the former is solubilized to a much lesser extent than the latter in an organic solvent. For example, o-AAP dissolves completely while p-AAP shows only 1.8% saturation solubility in toluene. Selective solubilization of o-AAP in toluene, therefore, gives pure p-AAP as residual solid in high yields. In the subsequent adsorption step, a strongly acidic ion exchange resin removes selectively the trace amounts of p-AAP from the toluene phase giving pure o-AAP.