Phosphoryl Chloride Mediated Synthesis of 5-Arylidene-2,4-Thiazolidinediones Derivatives via Aromatic Bisulfite Adducts

The carbon-carbon bond formation by the condensation of bisulfite adduct of aromatic aldehydes with thiazolidine-2, 4-dione to furnish 5-arylidene-2,4-thiazolidinedione’s has been investigated. This novel methodology was applied to convert substituted aryl bisulfite adducts to corresponding 5-arylidene-2,4-thiazolidinedione’s with POCl3 in less-polar solvents such as toluene, chlorobenzene and o-xylene. 5-(4-methoxybenzylidene)thiazolidine-2,4-dione and 5-(4-ethoxybenzylidene)thiazolidine-2,4-dione were obtained in good yields.