Microwave acceleration of the Pechmann reaction on graphite/montmorillonite K10: application to the preparation of 4-substituted 7-aminocoumarins

Efficient synthesis of 7-aminocoumarins was performed via the Pechmann reaction by microwave irradiation of the reactants on solid support (graphite/montmorillonite K10). In this convenient new methodology, the strong thermal effect due to graphite/microwaves interaction is associated with the acidic catalyst role of the clay.