What does cumarone mean?
Cumarone is a colourless, aromatic organic compound with the formula C8H6O, consisting of a benzene ring fused to a furan ring; it is now more usually called benzofuran. It occurs in coal tar and is obtained industrially from the light-oil fractions recovered during coking, where it appears alongside its close relative indene. Its principal historical importance lies in the production of cumarone–indene (or coumarone–indene) resins — hard, water-resistant thermoplastics formed by acid-catalysed polymerisation — which were once extensively used in paints, varnishes, floor tiles, printing inks, and adhesives. Although chemically related to coumarin, the fragrant substance of tonka beans, cumarone itself has little odour and no culinary role; its name simply derives from that association. Today the word survives mainly in technical literature and in older industrial texts, since pure benzofuran is generally referred to by its systematic name in contemporary chemistry.
nounA colourless, aromatic liquid heterocyclic compound, C8H6O, whose fused ring structure is also known as benzofuran; it occurs in coal tar and is used chiefly as a starting material for resins.
- (Chemistry) The heterocyclic compound C8H6O, known systematically as benzofuran, obtained especially from coal tar.
- (Industrial chemistry) The cumarone fraction or material used, together with indene, in the manufacture of cumarone (coumarone–indene) resins.
"The resin was prepared by polymerising cumarone with indene in the presence of a Friedel–Crafts catalyst."
"Cumarone is separated commercially from the light-oil fraction of coal tar by fractional distillation."
"Early coumarone–indene resins, valued for their adhesiveness and water resistance, were widely used in floor tiles and varnishes."
Rarely needed; used only when referring collectively to derivatives or substituted variants of the compound.
"Substituted cumarones were screened for antifungal activity."
Despite its name suggesting something sweet like its cousin coumarin, cumarone is an industrial workhorse — the stuff of coal-tar resins, not perfumes.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cumarone
The name cumarone was formed in German chemical nomenclature of the late nineteenth century from 'cumaron', a contraction reflecting its relationship to coumarin: both compounds were associated with the coumarou (the tonka-bean tree, Coumarouna/Dipteryx), whose name entered European languages via French 'coumarou' from an Indigenous South American (Cariban/Tupi) source. Cumarine-derived terminology spread into English alongside the growing coal-tar chemical industry, and the compound's identity with benzofuran was later established through structural studies.
How cumarone is actually used
Cumarone is almost entirely confined to technical and industrial contexts — organic chemistry, chemical engineering, and the plastics and coatings industries. It never appears in everyday speech. In older British technical literature the spelling 'coumarone' is frequent, while modern systematic nomenclature prefers 'benzofuran'.
Easily confused with cumarone
Coumarin is a sweet-smelling lactone found in tonka beans and used in perfumery, while cumarone (benzofuran) is a reactive hydrocarbon-like liquid used to make resins.