Synthesis and evaluation of fluorescent materials for colour control of peroxyoxalate chemiluminescence. I. The phenylethynylation of anthraquinone

The synthesis of 9,10-bis(phenylethynyl)anthracene has been examined in detail prior to the synthesis of a series of phenylethynyl substituted aromatic compounds which are of interest as fluorescent materials for peroxyoxalate chemiluminescence. Reductions of the 9,10- bis(phenylethynyl)-9,10-dihydroanthracene-9,10-diol precursor by stannous chloride and by sodium hypophosphite-potassium iodide both gave a series of byproducts, in addition to 9,10- bis(phenylethynyl)anthracene. The formation of these compounds is interpreted in terms of a free-radical process. The interaction of 10-hydroxy-10-(phenylethynyl)anthrone with both the reducing systems has been rationalized and the reaction with concentrated sulfuric acid reinterpreted.