Over the past few years, many pyrazole fused-ring systems, especially with applications in medicinal chemistry, have been published. These include general structures such as pyrazoline, pyrazoline, pyrazoquinoline, pyrazoloisoquinoline, pyrazoline, pyrazolopyrazine, pyrazolopyrazine, pyranopyrazole, pyrano Pyrazoles, pyrazolotriazines and pyrazole fused phosphorus rings.
Tetrahydrothiophene is a sulfur-containing saturated heterocyclic compound obtained by catalytic hydrogenation of thiophene. After thiophene is reduced to tetrahydrothiophene, it no longer has a conjugated system and aromaticity. Therefore, tetrahydrothiophene shows the properties of general thioethers. Easily oxidized to sulfoxides and sulfones. Tetrahydrothiophene can be used as a raw material for the production of pharmaceuticals, pesticides and photochemicals.