Synthesis of substituted flavones and chromones using a Well-Dawson heteropoliacid as catalyst

D. BENNARDI, G. ROMANELLI, J. JIOS, J. AUTINO, G. BARONETTI, H. THOMAS

Arkivoc

ARKAT USA, Inc.

Año: 2008 vol. XI p. 123 - 140

1424-6376

In this work, we report the use of bulk and silica-supported Wells-Dawson acid(H2P2W18O62.24H2O) as reusable, heterogeneous catalysts to obtain substituted flavones andchromones for the cyclization of 1-(2-hydroxyphenyl)-3-aryl-1,3-propanediones. The reactionexperiments were performed using toluene as solvent at reflux and in the absence of solvent, at110 °C. Under these conditions eleven examples were obtained with very good yields (82-91%)and high selectivity. The catalysts were easily recycled and reused without loss of their catalyticactivity. The presented synthetic method is a simple, clean and environmentally friendlyalternative for synthesizing substituted flavones and chromones.2P2W18O62.24H2O) as reusable, heterogeneous catalysts to obtain substituted flavones andchromones for the cyclization of 1-(2-hydroxyphenyl)-3-aryl-1,3-propanediones. The reactionexperiments were performed using toluene as solvent at reflux and in the absence of solvent, at110 °C. Under these conditions eleven examples were obtained with very good yields (82-91%)and high selectivity. The catalysts were easily recycled and reused without loss of their catalyticactivity. The presented synthetic method is a simple, clean and environmentally friendlyalternative for synthesizing substituted flavones and chromones.