Production of high-quality aromatic amino azo compounds by the rearrangement of 1,3-diaryl triazenes

摘要

A 1,3-diaryl triazene, in a solution obtained by the diazotization-coupling of a primary aromatic monoamine with a gas containing NO and NO2, which solution contains the monoamine and up to about 30 percent by weight of the triazene, based on the weight of the solution, is contacted with 0.4-2.0 percent of a strong acid, preferably nitric acid (based on the weight of the triazene-containing solution), at 50 DEG -120 DEG C. The triazene rearranges to an aromatic amino azo compound in a high para/ortho isomer ratio with minimum formation of binuclear by-products.