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

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 degrees 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 center dot center dot center dot H (19.6%), S center dot center dot center dot H (7.3%), H center dot center dot center dot C (20.1%), and C center dot center dot center dot C (0.7%) interactions. Density-functional theory (DFT) calculations indicated polar molecules (7.595 Debye). Its structure is stabilized by different sigma-sigma*, n ->sigma* , pi ->pi*, and n ->pi* intramolecular charge transfer (IMCT) processes. The two longest wave-length 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. (C) 2021 Elsevier B.V. All rights reserved.