Abstract
Two environmentally friendly methods, one in liquid and the other in solid phase, for preparation of phenyl bisesters (bearing alkylating groups) under microwave (MW) irradiation are presented. The MW remarkably enhanced the rate of acceleration for esterification: the reaction time decreased dramatically, the reaction conditions are milder, and the consumed energy decreased considerably. In the most cases, in the liquid phase under MW irradiation, the yields are better, in some cases substantially (almost 75%). In the solid phase under MW irradiation, the yields are moderate to good compared to the liquid phase but excellent compared to conventional heating. Both methods are fast, general, and facile, but because the solid-phase reactions are solvent-free, we consider this one to be the most suitable for synthetic chemistry. A comparative study of MW and conventional heating was done.
ACKNOWLEDGMENT
This work was financially supported by the Romanian Ministry of Education and Research, grant C.N.C.S.I.S. cod 88 under the PN-II-ID-PCE-2008 Program.