“…While the core 1,2,4-thiadiazole heterocycle 3 may appear benign, many such compounds can react quite readily with thiols − but not other functional groups like alcohols or amines. , Many properties of 1,2,4-thiadiazoles have been documented. − The 1,2,4-thiadiazole core can be susceptible to ring-opening reactions, recyclization side products, and nonenzymatic reductions. − Notably, this scaffold is similar to the “het_thio_N_5A” PAINS substructure, although it differs by resonance and substitution at the N2-position, meaning this chemotype could bypass some PAINS filters depending on its structural representation and certain chemoinformatic parameters …”