Aniline → Benzenamine, 2-(2-phenyldiazenyl)-

In the examples which follow, the yield of benzenediazonium salt was determined by reacting the benzenediazonium solution with aniline and then rearranging the intermediate triazene to give aminoazobenzene. Thus, the solution containing the diazonium salt was charged into a mixture containing aniline, in large excess (5 to 7 times the theoretical amount), aniline hydrochloride, in half the stoichiometric amount relative to the aniline, and water. The mixture was maintained at 50° C. and aminoazobenzene (ortho and para isomers) was obtained very rapidly in quantitative yield. The excess aniline hydrochloride was then neutralized, the aniline and the aminoazobenzene were extracted with ethyl acetate, and the ethyl acetate and the aniline were distilled. This yields crude aminoazobenzene (ortho+para), the composition of which was determined by vapor phase chromatography.