Reaction with acetic anhydride and oleic acid gives bismuth trioleate. Aromatic rings are acetylated by acetic anhydride. It forms a cyclic acid anhydride, succinic anhydride. Typically phthalate esters are prepared from the widely available phthalic anhydride. DMA is prepared commercially by the reaction of dimethylamine with acetic anhydride or acetic acid. Naphthalene is a precursor in the production of phthalic anhydride. It is the anhydride of phthalic acid. Benzoquinone reacts with acetic anhydride and sulfuric acid to give the triacetate of hydroxyquinol. Finally, the amine is acetylated with acetic anhydride. Dicarboxylic acids are converted to the anhydrides upon treatment with acetic anhydride. It is the imide derivative of phthalic anhydride. The useful dye quinizarin is produced by diacylation of hydroquinone with phthalic anhydride. This was based on reacting paraformaldehyde and ammonium nitrate in acetic anhydride. Synthesis by oxidation of acetic anhydride by peroxides, is conceptually similar. "o"-Xylene is an important precursor to phthalic anhydride.