Bromination and the Friedel–Crafts acetylation of monosubstituted pyrenes were examined. Acetylation of 1-acetyl- and 1-ethylpyrene occurred at the 8-, 6-, or 3-position, but the reaction of 1-methoxypyrene afforded only the 8- and 6-acetyl derivatives. By acetylation, 4-acetylpyrene yielded the 1- and 6-acetyl compounds, and 4-ethylpyrene gave the 6- and 8- derivatives. Also, 4-bromopyrene afforded