Abstract
Hydroxy chalcones undergo simple cyclizations with phenylhydrazine to afford 2-pyrazolines under microwave irradiation in the presence of glacial AcOH as cyclizing agent, also undergo simple cyclizations with hydroxylamine to afford 2-isoxazolines under microwave irradiation in the presence of KOH, and new cyclohexenone derivatives. Some valuable intermediates in the synthesis of fused heterocycles, have been prepared through K2CO3 which activate the cyclocondensation of hydroxychalcones with ethyl acetoacetate. The obtained results indicate that the microwave irradiation give shorter reaction times and cleaner reactions for synthesis of biologically important compounds.