Abstract
Phosphoric acid imidazolium dihydrogenphosphate was found to work well as a catalyst and excellent reaction medium in the Pechmann condensation of substituted phenols or α-naphthol with ethyl acetoacetate to give 4-methyl coumarins under microwave irradiation. This method is simple, cost effective, requires short reaction times, and gives very good to excellent yields.
The office of the Research Vice Chancellor of Azerbaijan University of Tarbiat-Moallem is gratefully acknowledged.
Notes
aIsolated yield after recrystallization.
aIsolated yield after recrystallization.