4-Thionazolidones,derivatives and analogs

A hitherto unknown isomer of rhodanine, 4-thiothiazolid-2-one (isorhodanine), is prepared by boiling thiazolidine-2, 4-dione with P₂S₅ in anhydrous dioxane for 3 hr. Isorhodanine I is characterized by great reactivity of the methylene and thione groups. The 4-phenylhydrazone and 4-phenylimino derivatives of I are prepared, as well as condensation products obtained by condensing I with aromatic aldehydes and diazonium salts. 5-Methylisorhodanine is also prepared. A derivative of I containing a quinoline ring is further obtained by reacting I with anthranilaldehyde.For Part II see [2].