Novel 1,3,4-bisthiadiazoline derivatives: Syntheses, in-vitro antimicrobial and antioxidant studies

• Main Authors: Shehneela Nisa, Mohamad Yusuf
• Format: Article
• Language: English
• Published: Elsevier 2021-02-01
• Series: Journal of Saudi Chemical Society
• Subjects: Dinaphthaldehydes; Bisthiosemicarbazones; Bisthiadiazolines; Bisheterocycles; Aliphatic; Aromatic chains
• Online Access: http://www.sciencedirect.com/science/article/pii/S1319610320301848

The present study describes the syntheses of a series of novel symmetrical bisthiadiazolines 4(a-j) built around the ten types of aliphatic/aromatic linkers. These bisheterocycles have been systematically synthesized by using the ring closure reactions of bisthiosemicarbazones 3(a-j) by refluxing under the acetic anhydride (Ac2O) medium. The latter have been efficiently achieved through the condensation reactions of appropriate dinaphthaldehydes 2(a-j) with thiosemicarbazide in the presence of dry MeOH/HCl conditions. The treatment of 2-hydroxy-1-naphthaldehyde 1 with suitable dihalogenated reagents under the anhydrous K2CO3/Bu4N+I−/dry acetone medium furnished new intermediates 2(a-j). IR, 1H NMR, 13C NMR, ESI-MS & elemental analyses spectral data were in full agreement to their proposed structures. The aliphatic chains linked bisthiadiazolines 4(a-f) displayed significant antioxidant potencies while aromatic spacers based products 4(g-j) were found to exhibit better antimicrobial properties. The molecular docking simulations have also been carried out to visualize the possible interaction of most active antimicrobial compound 4g at the active sites of Staphylococcus aureus tyrosyl-tRNA synthetase protein (PdB: 1JIL).