Phosphonium Ylides Stabilized with Cyano Group and 5-Acylamino-4-phenyl-2-thiazolyl Residue

Available ylide reagent Ph₃P = C(CN)C(S)NH₂ readily enters cyclocondensation with N-(chlorophenacyl)benzamide and its analogs. By this route were prepared new stabilized phosphonium ylides containing cyano group and the corresponding 5-acylamino-4-phenyl-2-thiazolyl fragment. All these compounds even under standard conditions are dephosphorylated under the action of hydrogen chloride in acetic acid to form 5-acylamino-4-phenyl-2-cyanomethylthiazoles in high yields. Their structure was proved by spectroscopic studies and independent synthesis.