Preparation of Thioflavones via Thiophosphoryl Chloride Mediated Cyclodehydration and Thionation of 1-(2-Hydroxyphenyl)-3-arylpropane-1,3-diones

A simple and convenient one-pot strategy for the prepa ration of thioflavones from 1,3-diketones is described. Cyclodehydration of a range of β-diketones and thionation of the resulting flavones was achieved using thiophosphoryl chloride (PSCl 3 ) which serves as both a catalyst and thionating agent.