Synthesis and X-ray crystal structure of unexpected novel thiazolidinone/1,3,4-thiadiazole heterocycle via S-alkylation and Smiles rearrangement dual approaches

Abstract

A new unexpected hybrid based on the arylidene-thiazolidinone and 1,3,4-thiadiazole scaffolds via combined S-alkylation and Smiles rearrangement dual protocols. The one-pot reaction of arylidene-thiazolidinone with the hydrazonoyl chloride in a basic medium (Et3N) with benzene as solvent afforded the discovered compound at room temperature (25 °C). The molecular architecture of the designed hybrid were assigned based on the spectrophotometric tools. Based on Hirshfeld analysis, the molecules are connected by short O…H (19.6%), S…H (7.3%), H…C (20.1%), and C…C (0.7%) interactions. Density-functional theory (DFT) calculations indicated polar molecules (7.595 Debye). Its structure is stabilized by different σ-σ*, π→π*, n→σ*, and n→π* intramolecular charge transfer (IMCT) processes. The two longest wavelength bands observed in the UV–Vis spectra of diethyl(S,Z)-2-(2-(5-(4-hydroxybenzylidene)-4-oxo-4,5-dihydrothiazol-2-yl)-2-phenylhydrazinyl)-3-phenyl-2,3-dihydro-1,3,4-thiadiazole-2,5-dicarboxylate 3 were calculated at 364.0 (HOMO→LUMO+1) and 305.1 nm (HOMO-2→LUMO), which considerably agree with the experimental data.