Potential antidiabetic zinc(II) complexes of novel 5-oxo-2-thioxopyrrolidine derivatives synthesized via an unprecedented reaction

We have developed a synthetic route to novel ethyl 1-arylmethyl-5-oxo-2-thioxopyrrolidine-3-carboxylates (1a–e) via an unprecedented reaction of ethyl 1-arylmethyl-4-acetoxy-5-oxo-2,5-dihydro-1H-pyrrole-3carboxylates with potassium thioacetate. Synthesized products 1a–e were further converted into their zinc(II) complexes (10a–e), having an S2O2-type coordination mode, that showed improved insulin-mimetic activities compared to ZnSO4, a positive standard, and also the previously reported zinc(II) complexes of ethyl 1-benzyl-4-hydroxy-5-oxo-2,5-dihydro-1H-pyrrole-3-carboxylates with O4-type coordination mode.