Benzothiopyran

A chemical compound where a benzene ring is fused to a six-membered ring containing sulfur, similar in structure to other benzofused heterocycles.

From 'benzo-' (benzene) + 'thiopyran' (six-membered ring with sulfur and four carbons; 'pyran' from Greek pyron, grain, originally named for a resemblance to a chalice shape). Nomenclature developed in early 20th-century synthetic organic chemistry.