The reaction of 3-aminophenol (I) with pivaloyl chloride and then with DHP and TsOH gives the protected pivalanilide (II), which is condensed with ethyl chloroformate by means of BuLi in THF yielding the benzoate ester (III). The condensation of benzoate (III) with acetophenone (IV) by means of NaH in refluxing dioxane affords the intermediate diketone (V), which, without purification, was treated with HCl in ethanol at room temperature to give the protected flavone (VI). Finally, thee removal of the two pivaloyl protecting groups was effected with HCl in refluxing ethanol.

The reaction of 3-aminophenol (I) with pivaloyl chloride and then with DHP and TsOH gives the protected pivalanilide (II), which is condensed with ethyl chloroformate by means of BuLi in THF yielding the benzoate ester (III). The condensation of benzoate (III) with acetophenone (IV) by means of NaH in refluxing dioxane affords the intermediate diketone (V), which, without purification, was treated with HCl in ethanol at room temperature to give the protected flavone (VI). Finally, thee removal of the two pivaloyl protecting groups was effected with HCl in refluxing ethanol.

The reaction of 3-aminophenol (I) with pivaloyl chloride and then with DHP and TsOH gives the protected pivalanilide (II), which is condensed with ethyl chloroformate by means of BuLi in THF yielding the benzoate ester (III). The condensation of benzoate (III) with acetophenone (IV) by means of NaH in refluxing dioxane affords the intermediate diketone (V), which, without purification, was treated with HCl in ethanol at room temperature to give the protected flavone (VI). Finally, thee removal of the two pivaloyl protecting groups was effected with HCl in refluxing ethanol.