Über polymere 4-vinylimidazolide und deren verwendung als acylierungsreagenzien

Several copolymers of 4(5)-vinylimidazole (1a) containing different amounts of divinyl-benzene (DVB) as crosslinking agent and also copolymers of 1a (crosslinked, 4 mol-%) with styrene, 4-vinylpyridine, 1-vinylimidazole, or 4-vinylbenzoic acid were obtained by radical polymerisation. The pendant imidazole-groups of all of these polymers could be acylated in their 1-position. The swellability of the resulting polymeric N-acylated imidazoles in suitable solvents was investigated. They were used for the acylation of amines and alcohols, variing the mole ratio reactive polymer/substrate, the reaction time, and the solvent. A gradual reacitivity was found for the reaction with low molecular mass compounds according to the nucleophilicity of the substrates. Ethanolamine could be selectively N-acetylated and in the case of the mono-trifluoroacetylation of hexamethylenediamine significantly high yields of mono-acylated product were obtained. After the reaction the polymers could be regenerated without any loss of activity.