The disclosed synthesis technique for mauve sulfanilyl-contained bridge azo dye with structural formula as following comprises: dissolving the N, N'-1, 4-biphenyl-(4-amino) benzsulfamide and NaNO2 by mole ratio as 1:2-3 into diluted NaOH solution and then pour into diluted HCl solution together while holding pH value as 1-5 and temperature as 0-5Deg to obtain the diazol solution; using the diazol and phenol derivative, naphthol-sulfonic derivative, phenylamine derivative or naphthylamine derivative by mole ratio s 1:2-3 for coupling reaction in diluted Na2CO3 solution with temperature as 5-28Deg and pH value as 1.0-5.0; then, salting out, filtering, drying, and grinding. This product is almost equal to direct-scarlet 4B for cellulose fiber dyeing and super to the 4B for leather dyeing. |