| 摘要 |
A process for the preparation of azo dyes of the formula <IMAGE> (1) in which X is -NH2 or -OH, A is a benzene or naphthalene radical which can be substituted by nitro, halogen, sulfo, C2-C6alkanoylamino, C1-C6-alkoxycarbonylamino, sulfonamido and sulfone groups and B is a benzene radical which is monosubstituted or disubstituted by C1-C6alkyl, or a naphthalene radical which can be substituted by amino, phenylamino, C1-C6alkylamino and sulfo, or a 1-phenyl-3-methyl-5-pyrazlone radical which can be substituted by halogen, C1-C6alkyl and C1-C6alkoy, these radicals being bound to the azo group in the o-position with respect to the hydroxyl or amino groups, comprises diazotizing in aqueous solution an amine of the formula <IMAGE> (2) in the presence of at least one ketone of the formula <IMAGE> (3) in which R1 and R2, independently of one another, are each C1-C4alkyl, and coupling the product on to a coupling component of the formula <IMAGE> (4) in which A, B and X in formulae (2) and (4) are as defined in formula (1). The present invention makes it possible to prepare the azo dyes mentioned in high yields.
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