In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called The testing conditions of sodium carbonate, sodium sulfate and certain other hydrated salts, published in 1931, which mentions a compound: 17927-65-0, Name is Aluminum(III) sulfate xhydrate, Molecular Al2H8O13S3, Name: Aluminum(III) sulfate xhydrate.
The H2O content of Na2CO3.10H2O can be determined by heating at 98° to constant weight The most stable hydrate is Na2CO3.2H2O; it is formed on standing from anhydrous soda or from the other hydrates. Na2SO4.10H2O loses all the H2O by drying a few hrs. at 98°, although the natural decahydrate, mirabilite, is stable. Borax requires heating to redness to accomplish complete dehydration. CuSO4.5H2O is very stable and does not lose water on standing over H2SO4. Al2(SO4)3.18H2O is also very stable and does not easily lose H2O. The chrome alums are easily deprived of H2O.
In addition to the literature in the link below, there is a lot of literature about this compound(Aluminum(III) sulfate xhydrate)Name: Aluminum(III) sulfate xhydrate, illustrating the importance and wide applicability of this compound(17927-65-0).
Reference:
Isothiazole – Wikipedia,
Isothiazole – ScienceDirect.com