Hybrids of Thiazolidin-4-Ones and 1,3,4-Thiadiazole: Synthesis and Biological Screening of A Potential New Class of Acetylcholinesterae Inhibitors

Using propanoic acid and thiosemicarbazide as starting materials, a new sequence of thiazolidin-4-one analogs with thiadiazole derivative was synthesized in appreciable yield. Spectral techniques such as IR, 1H NMR, 13C NMR, and MS were used to validate the structures of the synthesized compounds (4a-t). In vitro acetylcholinesterase inhibitory activity of these synthesized compounds was assessed using an Ellman's method spectrophotometer and donepezil as a standard drug. Compounds 2-((5-ethyl-1,3,4-thiadiazol-2-yl)imino)-5-(4-methylbenzylidene)thiazolidin-4-one(4o) and 5-(4-(benzyloxy)benzylidene)-2-((5-ethyl-1,3,4-thiadiazol-2-yl)imino)thiazolidin-4-one(4i) were found to be potent AChE enzyme inhibitors, with pIC50 (mM) values of 1.30±0.007 and 1.22±0.002, respectively. Finally, these significant results could pave the way for the development of new AChE inhibitors and will serve as the basis for future research.

The detection of polyamines by an extended gate-type organic transistor functionalized with a carboxylate attached 1,3,4-thiadiazole derivative

We herein report an extended gate-type organic thin-film transistor (OTFT)-based polyamine sensor and its application for pattern recognition. The extended-gate electrode was functionalized with a complex of copper(II) ions and...

Novel cocrystals of the potent 1,2,4-thiadiazole-based neuroprotector with carboxylic acids: virtual screening, crystal structures and solubility performance

Five new multicomponent solid forms of the biologically active 1,2,4-thiadiazole derivative (TDZH) with dicarboxylic and hydroxybenzoic acids have been discovered by combined virtual/experimental cocrystal screening.

Synthesis, Spectroscopic Studies and Keto-Enol Tautomerism of Novel 1,3,4-Thiadiazole Derivative Containing 3-Mercaptobutan-2-one and Quinazolin-4-one Moieties

In this study, a novel 1,3,4-thiadiazole derivative containing 3-mercaptobutan-2-one and quinazolin-4-one moieties (Compound 3) is synthesized by the coupling of 2-amino-1,3,4-thiadiazole-5-(3-mercaptobutan-2-one) (Compound 1) with 2-Phenyl-4H-3,1-benzoxazin-4-one (Compound 2) in one molecule moiety. Compound 3 is found to exist as two types of intra-molecular hydrogen bonding with keto-enol tautomerism characters, which is further confirmed using FTIR, 1H-NMR, 13C-NMR, mass spectrometer, and UV-Visible spectra. The 1H-NMR and UV-Visible spectra of Compound 3 are investigated in different solvents such as methanol, chloroform, and DMSO. Compound 3 exhibits keto-enol tautomeric forms in solvents with different percentage ratios depending on the solvent polarity. The 1H-NMR and UV-Visible spectral results show that Compound 3 favors the keto over the enol form in polar aprotic solvents such as DMSO and the enol over the keto form in non-polar solvents such as chloroform. The 13C-NMR spectrum gives two singles at δ 204.5 ppm, due to ketonic carbon, and δ 155.5 ppm, due to enolic carbon, confirming the keto-enol tautomerism of Compound 3. Furthermore, the molecular ion at m/z 43 and m/z 407 in the mass spectrum of Compound 3 and fragmentation mechanisms proposed reveal the existence of the keto and enol forms, respectively.