The interaction of free radicals and aromatics. I. Reaction of anthracene and of pyrene with 2‐cyano‐2‐propyl radicals

Abstract

Abstract2‐Cyano‐2‐propyl radicals (R) generated by decomposition of 2,2′‐azo‐isobutyronitrile were found to add on to anthracene (A) at one of the reactive 9,10 positions, yielding radicals R—A with a free valence at the other meso‐position. The latter combine to a dimer (R—A—A—R) in 22.5% yield and, with R, form cis and trans R—A—R in 49% and 13.5% yield. Under the same conditions, pyrene gave little reaction.Thermal decomposition of both R—A—A—R and R—A—R produces anthracene and 2‐cyano‐2‐propyl radicals in high yields, while H—A—A—H (9,9′,10,10′‐tetrahydrodianthranyl‐9,9′) gives anthracene and 9,10‐dihydroanthracene.The significance of these results relative to the formation of substitution products from aromatics and highly reactive radicals is discussed.