Thiadiazoles Explained

In chemistry, thiadiazoles are a sub-family of azole compounds, with the name thiadiazole originating from the Hantzsch–Widman nomenclature. Structurally, they are five-membered heterocyclic compounds containing one sulfur and two nitrogen atoms. The ring is aromatic by virtue of the two double bonds one of the lone pairs of electrons of sulfur. Four constitutional isomers are possible, differing by the relative positions of the sulfur and nitrogen atoms. The nomenclature thus includes the locations of each of those three atoms, with the first of the three numbers referring to the sulfur.

The compounds themselves are rarely synthesized and possess no particular application, however, compounds bearing them as a structural motif are fairly common in pharmacology. Of them, 1,3,4-thiadiazole is the most common, appearing in such medications as cephazolin and acetazolamide.^{[1] [2] [3]}

In the Hurd-Mori reaction, an acyl hydrazone reacts with thionyl chloride or selenium dioxide to give a 1thia- or 1selena-2,3diazole.^[4]

Notes and References

1. Hu. Yang. Li. Cui-Yun. Wang. Xiao-Ming. Yang. Yong-Hua. Zhu. Hai-Liang. 1,3,4-Thiadiazole: Synthesis, Reactions, and Applications in Medicinal, Agricultural, and Materials Chemistry. Chemical Reviews. 114. 10. 2014. 5572–5610. 0009-2665. 10.1021/cr400131u. 24716666.
2. Jain. Abhishek Kumar. Sharma. Simant. Vaidya. Ankur. Ravichandran. Veerasamy. Agrawal. Ram Kishore. 1,3,4-Thiadiazole and its Derivatives: A Review on Recent Progress in Biological Activities. Chemical Biology & Drug Design. 81. 5. 2013. 557–576. 1747-0277. 10.1111/cbdd.12125. 23452185. free.
3. Book: Wim Dehaen. Vasiliy A. Bakulev. Edward C. Taylor. Jonathan A. Ellman. The Chemistry of Heterocyclic Compounds, The Chemistry of 1,2,3-Thiadiazoles. 27 April 2004. John Wiley & Sons. 978-0-471-65691-3. 5–.
4. Thuc . Dinh Ngoc . Synthesis and characterization of some new 1,2,3-thiadiazole and 1,2,3-selenadiazole triterpene derivatives from allobetulone and 2-oxoallobetulin . Synthetic Communications . 2020 . 50 . 11 . 1665–1671 . 10.1080/00397911.2020.1750655. 219092397 .