2164 No. 25 ment of, 2 according to the method described by Potts et al.'with phosphorus pentasulfide in refluxing pyridine, affords triphenylthieno [3, 4-clisothiazole (2) in 80-93% yield as glistening, deep violet needles (armp=-120 dec.; uv (CH2C12) Amax= 529 nm (lg