Functionalization of 2-Mercapto-5-methyl-1,3,4-thiadiazole: 2-(ω-Haloalkylthio) Thiadiazoles vs. Symmetrical Bis-Thiadiazoles

Zhanina S Petkova; Rusi I Rusew; Boris L Shivachev; Vanya B Kurteva

doi:10.3390/molecules29091938

Functionalization of 2-Mercapto-5-methyl-1,3,4-thiadiazole: 2-(ω-Haloalkylthio) Thiadiazoles vs. Symmetrical Bis-Thiadiazoles

Molecules. 2024 Apr 24;29(9):1938. doi: 10.3390/molecules29091938.

Authors

Zhanina S Petkova¹, Rusi I Rusew², Boris L Shivachev², Vanya B Kurteva¹

Affiliations

¹ Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 9, 1113 Sofia, Bulgaria.
² Institute of Mineralogy and Crystallography "Acad. Ivan Kostov", Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 107, 1113 Sofia, Bulgaria.

Abstract

A study on the functionalisation of 2-mercapto-5-methyl-1,3,4-thiadiazole has been conducted, yielding two series of products: 2-(ω-haloalkylthio)thiadiazoles and symmetrical bis-thiadiazoles, with variable chain lengths. The experimental conditions were optimised for each class of compounds by altering the base used and the reagents' proportions, leading to the development of separate protocols tailored to their specific reactivity and purification needs. The target halogenide reagents and bis-thiadiazole ligands were obtained either as single products or as mixtures easily separable by chromatography. Characterisation of the products was performed using 1D and 2D NMR spectra in solution, complemented by single crystal X-ray diffraction (XRD) for selected samples, to elucidate their structural properties.

Keywords: 2-mercapto-5-methyl-1,3,4-thiadiazole; NMR; XRD; bis-thiadiazole ligands; ω-haloalkylthio derivatives.

Grants and funding

Financial support from The EU, COST Action CA22147 European metal-organic framework network: combining research and development to promote technological solutions (EU4MOFs), and by the Bulgarian Ministry of Education and Science, the Operational Program “Science and Education for Smart Growth” 2014–2020, co-financed by European Union through the European Structural and Investment Funds, under the Projects Centre of Excellence “National centre of mechatronics and clean technologies”, project BG05M2OP001-1.001-0008 (for Bruker D8venture XRD equipment), and Centre of Competence “Sustainable utilization of bio-resources and waste of medicinal and aromatic plants for innovative bioactive products”, project BG05M2OP001-1.002-0012 (for Q Exactive Plus Hybrid Quadrupole-Orbitrap MS equipment), is gratefully acknowledged.