Flavones are a class of naturally occurring compounds with various biological activities. 1–4 One of the most commonly used methods for the synthesis of flavones is the cyclodehydration of 1-(2-hydroxyphenyl)-3-aryl-1, 3-propanediones. Many of these procedures use strong acids such as H2SO4, 5-6 HCl, 7 HBr or HI, 8 catalysts such as NaHSO4/SiO2, 9 H3PMo12O40· nH2O/SiO2, 10 H3PW12O40· nH2O/SiO2, 10 non- ...