Hoechst Aktiengesellschaft

Hans Frischkorn

Erich Schinzel

Thomas Martini

Gunter Rosch

Heinz Probst

Klaus Uhl

Herbert Friedrich

Compounds of the general formula ##STR1## in which n denotes 1 or 2,

Bisbenzoxazolylnaphthalenes containing sulfonate or sulfonamide groups,

Mixtures of optical brighteners consisting of 1 to 60% by weight of a brightener from the bisbenzoxazolylnaphthalene series and 99 to 40% by weight of one or more brighteners of the formulae 2 to 10 listed in the description.

Mixtures of optical brighteners and their use

Mixtures of optical brighteners composed of

Mixtures of optical brighteners

Process for the preparation of naphthalene-1,4-dicarboxylic acid, wherein 4-bromo-1-naphthoic acid is reacted with at least 1 mole of copper-(I) cyanide per mole of 4-bromonaphthoic acid in a polar, aprotic solvent, and the copper salt complex of 4-cyanonaphthoic acid thus obtained is saponified in an alkaline medium.

Process for the preparation of naphthalene-1,4-dicarboxylic acid

A process for the preparation of naphthalene-1,4-dicarboxylic acid, which comprises reacting 1,4-dihalogenonaphthalene with at least 2 moles of copper-I cyanide per mole of dihalogenonaphthalene in a polar, aprotic solvent and subjecting the copper salt complex of 1,4-dicyanonaphthalene thus obtained to alkaline hydrolysis.

Colorless formulations of optical brighteners from the 4,4'-bis-triazinylamino-stilbene-disulfonic acid series, which are obtained by heating the brightener together with an oxyalkylate.

Colorless formulations of optical brighteners from the series of

Compounds of the formula ##STR1## wherein R.sup.1 to R.sup.8 each mean, independent from one another, a hydrogen atom or a non chromophoric substituent, R.sup.9 means a hydrogen atom, an alkyl group, a halogen atom, preferably a chlorine or bromine atom, an optionally functionally modified carboxy or sulfo group. They are prepared by reacting 1 mol of 1,7-naphthalene dicarboxylic acid or its acid chloride with 2 mols of an o-aminophenol and subsequent cyclization of the di-N,N'-acyl compounds obtained in the first step. These compounds are valuable optical brighteners.

Mixture of benzoxazole derivatives

Compounds of the formula ##STR1## and the corresponding lower alkyl quaternary salts thereof in which A represents a group of the formula ##STR2## and in which R.sup.1 stands for a group of the formula ##STR3## whereby R represents a hydrogen atom or a lower alkyl group, R.sup.2 has the same meaning as R.sup.1 or stands for a hydrogen atom or a group of the formula ##STR4## whereby the aromatic rings may be substituted by non-chromophoric substituents. Due to their good fluorescence these compounds can be used as optical brighteners for organic materials, especially textile materials.

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Hofheim am Taunus, Germany

Hans Frischkorn