Begin with a five-membered thiophene ring (four carbons and one sulfur) and label the ring atoms such that the sulfur occupies position 1 and carbon-5 carries a methyl group. At carbon-2, attach a substituent that is a single stereogenic carbon (R configuration). This chiral carbon is further substituted with three groups:
- A secondary amine bearing an ethyl group (-NH-CH2-CH3),
- A six-membered saturated ring (a tetrahydropyran) composed of five carbons and one oxygen, where the oxygen is positioned para to the point at which the chain joins the ring, and
- A hydrogen atom.