ChemInform Abstract: Coupling of Anthrone by Mercury(II) Salts.

Abstract

Its use as a phenol coupling reagent, however, has not been attempted much . Recently we have reported the coupling of 2,7-dihydroxynaphthalene using mercuric oxide2. Another report appeared in the literature that utilized Hg (II) salts for phenol coupling reaction. The mercuration, however, is more common process occurring in this type of reactions leading to organomercurals4.5. All these facts prompted us to undertake the reaction of anthrone (1) with common Hg (II) salts such as HgCI2 and Hg(OAch under different conditions. The isolation of a host of naturally occurring phenolic bianthronyls6 of important physiological properties and their probable biogenesis through oxidative phenol coupling of the respective monomers created interest amongst us in studying the possible coupling of anthrone leading to bianthronyls using Hg (II) salts. Earlier literature says that mercuric halide would insert to acidic carbons readily, a base helps, and thermal activation would lead to dimerization. For instance, the substrate dibenzyl ketone would dimerize to 1,4-dioxo-2,3,5,6tetrapheny lcyclohexane 7 . Acidity wise, anthrone is also activated and therefore has the chance to dimerize readily. It is interest ing to note that 1, when ICfluxed for nearly 3 hr with Hg(OAc)2 either in glacial acetic acid or in ethanol, afforded a single isolable product establi shed as bianthronyl 2 with >70% yields. The same product in >60% yield could also be obtained