DSC AND C-13 NMR STUDIES OF THE IMIDAZOLE-ACCELERATED REACTION BETWEEN EPOXIDES AND PHENOLS.

The imidazole-accelerated reaction between epoxides and phenols has been studied through DSC and C-13 NMR of model compounds. The selectivity of the accelerator has been found to be strongly dependent on its concentration. If a low amount of accelerator is used, the reaction takes place almost exclusively through the addition of phenols to epoxides even if the latter are used in excess. However, a larger amount of accelerator will cause the secondary hydroxyls (produced by the main reaction) to react with epoxides. In any case, the lower reactivity of the secondary hydroxyls prevents them from reacting to any significant extent as long as there are any phenols present.