A STUDY OF THE KINETICS OF THE AZO COUPLING REACTION USED IN THE SYNTHESIS OF CI REACTIVE ORANGE-4

The azo coupling reaction between diazotized 2-naphthylamino-1,5-disul phonic acid and the condensation product of 2,4,6-trichloro-1,3,5-tria zine with 5-hydroxy-2(N-methyl)naphthylamino-7-sulphonic acid was stud ied. In addition to the azo coupling, decomposition of the diazonium s alt, and also dimerization of the coupling components occurs. The rate constants of all the reactions were estimated spectrophotometrically and potentiometrically. The relationship between the concentration of dye and time was estimated using a computer and these functions were c ompared with experimental data. For the best fitting curves, rate cons tants of dye formation were estimated.