1,2,3,4-Tetraphenylnaphthalene is a polycyclic aromatic hydrocarbon commonly prepared in the undergraduate teaching laboratory as an introduction to the Diels-Alder reaction, in this case between benzyne, which acts as the dienophile, (generated in situ) and tetraphenylcyclopentadienone, which acts as the diene.Organic Syntheses, Coll. Vol. 5, p.1037 (1973); Vol. 46, p.107 (1966). Link It has two crystalline forms, and therefore has two different melting points.
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