Examples of activated aromatic rings are toluene, aniline and phenol. The aniline dye malachite green is prepared from benzaldehyde and dimethylaniline. Aniline Yellow was the first azo dye. The first azo dye was aniline yellow. Aromatic nitriles are often prepared in the laboratory from the aniline via diazonium compounds. Heating the reaction mixture is sufficient to hydrolyze the amide back to the nitrated aniline. Heterocycles are commonly found in a wide range of products including aniline dyes and medicines. At high temperatures aniline and carboxylic acids react to give the anilides. Nubuck characteristics are similar to aniline leather. It is produced on a large scale from benzene as a precursor to aniline. Chemically, it is an organic compound consisting of an aniline derivatized with a sulfonamide group. At first the production of dyes based on aniline was critical. Better results were achieved by adding 2.5% mono methyl aniline (M.M.A.) to 100 octane fuel. The three compounds seriously discussed are ethylene, aniline, and dinitrophenol. It is one of three isomers of the methoxy-containing aniline derivative.