thiadiazole C??? ??, ??, ??
??
1,2,3-Thiadiazole is a five-membered, π-excessive, stable, almost planar, unsaturated, conjugated, heteroaromatic comprised of one sulfur atom, two adjacent nitrogen atoms (S–N–N), and two carbon atoms. There are four possible noninterconvertible regioisomeric structures depending on the relative position of heteroatoms.
??? ??
The parent 1,2,3-thiadiazole is a yellow-colored liquid with a bp of 157°C. It is a weak base, thermally stable, and soluble in water and most of the organic solvents such as alcohol, ether, DCM, and chloroform.
??
1,2,3-Thiadiazoles have broader applications as insecticide synergists, cross-linked polymer compounds, and herbicides. Besides agro-applications there are other applications such as sedative, antibacterial and antibiotic, antiviral, and neurodegenerative.
?? ??
As is evident from the electron density map on the ring atoms, both C4 and C5 carbon atoms have the least electron density compared to nitrogen, making them resistant to electrophilic attack on carbon atoms but facile to nitrogen atoms. However, nucleophilic substitution is facile to carbon atoms.
thiadiazole ?? ?? ? ???
???
?? ??
