Preparation of Thioflavones via Thiophosphoryl Chloride Mediated Cyclodehydration and Thionation of 1-(2-Hydroxyphenyl)-3-arylpropane-1,3-diones - Vimal, Manorama; Pathak, Uma; Pandey, Lokesh Kumar; Suryanarayana, Malladi V. S. (Synthesis, 2011)