Azo coupling in two-phase water-alcohol mixtures

In the process of preparing an azo dye by coupling a diazonium compound in aqueous solution with a coupling compound having the formula ##STR419## where X.sup.6 is selected from the class consisting of hydrogen, halogen, alkyl of up to four carbons, and alkoxy of up to four carbons;

• X.sup.7 is selected from the class consisting of X.sup.6 and alkylcarbonylamino of up to 8 carbons in the alkyl moiety;
• X.sup.8 and X.sup.9 are independently unsubstituted or monosubstituted alkyl, the substitution being selected from the class consisting of halogen, hydroxy, cyano, alkyl-carbonyloxy, alkoxy, alkoxy-carbonyl, alkoxy-carbonyloxy, phenoxycarbonyl, phenoxy-carbonyloxy, cyclohexyl, phenyl, halophenyl, alkylphenyl, phenoxy, halophenoxy and alkylphenoxy, each alkyl and alkoxy having up to four carbons;
• or
• X.sup.8 and X.sup.9 together with the N to which they are both bonded form a heterocyclic ring in which the N is linked through methylene groups to oxygen, another N, or an additional carbon;
• and
• X.sup.10 is selected from the class consisting of hydrogen and X.sup.8
• at a temperature between about 0.degree. and 80.degree. in the presence of an acid, the improvement which comprises effecting the coupling essentially in a twophase mixture of water and a simple alkanol having four to six carbons in the molecule and soluble in water to the extent of not over about 15% by weight at 15.degree. C., the mixture containing from about 15 to about 90% alkanol by weight, and then directly separating the dye in over 85% purity from the reaction mixture.