1,4-Butanediyl dimethacrylate, a photoreactive diluent, synthesized via an unusual transesterification involving glycidyl methacrylate

The reaction between glycidyl methacrylate and 1,4-butanediol in the presence of triethylamine was investigated. The structural analysis of the main products showed that the reaction proceeds by transesterification with release of glycidol. Transesterification occurs in two stages with, firstly, formation of the intermediate 4-hydroxybutyl methacrylate, which is thereafter transformed into 1,4-butanediyl dimethacrylate (BDMA). Whatever the conditions used, the reaction progresses similarly and at the end, an equilibrium in product composition is noticed. Under optimized conditions, it is possible to obtain yields in BDMA higher than 80%.