2-[(1-imidazolyl)formyloxy]ethyl methacrylate as selective methacryloylating agent: Kinetics of reaction with model alcohols and amines

The kinetics of the coupling reactions of 2-[(1-imidazolyl)formyloxy]ethyl methacrylate (HEMA-Im) with model primary and secondary alcohols and amines have been investigated both in the absence and in the presence of imidazole and triethylamine as catalysts. In the absence of added catalysts, alcohols either reacted very sluggishly or did not react at all with HEMA-Im, but amines reacted completely in relatively short times. In the presence of catalysts, both primary and secondary alcohols underwent coupling reactions with HEMA-Im, the former about ten times faster than the latter. Imidazole was a more effective catalyst than triethylamine. HEMA-Im's ability to discriminate between amino and hydroxyl groups was tested with 4-amino-1-butanol: the 1H NMR analysis of the reaction product confirmed 100% selectivity towards the amino group. It was therefore concluded that HEMA-Im is a highly selective methacryloylating agent, with a synthetic potential for preparing multifunctional monomers and polymers.