Hammett spectral correlations in benzofuranyl flavonols

A series containing eleven benzofuranyl flavonols have been prepared by cyclization of 3-hydroxybenzofuranyl chalcones with 30 % hydrogen peroxide in the presence of sodium bicarbonate. The synthesized flavonols were characterized by their physical constants, analytical and spectroscopic data. The infrared spectral νOH, CO stretches(cm-1), NMR chemical shifts of OH, CO(δ, ppm) of these flavonols were assigned and correlated with Hammett substituent constants, F and R parameters using single and multi linear regression analysis. From the results of statistical analyses, the effects of substituents on the above group frequencies were discussed.