Tetrahydrofuran is a heterocyclic organic compound with the molecular formula C4H8O. Tetrahydrofuran belongs to ethers and is the complete hydrogenation product of furan. It is a colorless, water-miscible organic liquid with small viscosity at normal temperature and pressure. Because of its long liquid range, it is a commonly used medium polar aprotic solvent. Its main use is as a precursor of high molecular polymers.
Thiazine is an organic compound containing four carbon rings, one nitrogen atom and one sulfur atom. Thiazine has three isomers, 1,2-thiazine, 1,3-thiazine and 1,4-thiazine, which are arranged differently in the ring. Nitrogen-containing heterocyclic compounds such as 1,4-thiazine and its benzo derivatives are important compounds in many different research fields due to their remarkable biological properties.