Reactions of quinones with aromatic ethers. Part II. Polyalkoxytriphenylenes and -dibenzo[fg,op]naphthacene-1,10-quinones from chloranil and o-dialkoxybenzenes
Veratrole reacts with chloranil in aqueous sulphuric acid to give 2,3,6,7,10,11-hexamethoxytriphenylene (2; R = Me) and 2,5,6,9,12,13-hexamethoxydibenzo[fg,op]naphthacene-1,10-quinone (3; R = Me). The latter is converted into the corresponding leucoacetate and leucomethyl ether. Related products result from a similar oxidation of o-diethoxybenzene. The oxidation of veratrole by moist iron(III) chloride gives, in addition to the above compounds, o-methoxyphenol and 2,5,6,9,12,13-hexamethoxydibenzo[fg,op]naphthacene-1,8-quinone (1; R = Me).