Bayer Aktiengesellschaft

Josef Schroeder

Carl-Wolfgang Schellhammer

Uwe Claussen

Heinrich Gold

Process for the preparation of benzanthrones of the formula ##STR1## in which R designates alkyl or halogen and

Process for the preparation of benzanthrones

Pyrazoline compounds of the formula ##STR1## wherein R.sub.1 and R.sub.2 denote hydrogen or chlorine,

1-[p-(2-Trialkylammonium)propylsulfonylphenyl]-3-(phenyl)-pyrazoline

Bis-benzoxazolyl compounds of the formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 independently of one another denote hydrogen, halogen, optionally substituted C.sub.1 -C.sub.8 -alkyl, optionally substituted C.sub.1 -C.sub.4 -alkoxy, aralkyl, aryl, carboxyl, cyano, C.sub.1 -C.sub.4 -alkoxycarbonyl, carboxamide which is optionally substituted by C.sub.1 -C.sub.4 -alkyl, aryl or aralkyl, or C.sub.1 -C.sub.4 -alkylsulphonyl, or 2 adjacent radicals R.sub.1 -R.sub.4 represent a fused, optionally substituted aromatic or hydroaromatic ring, are suitable for the brightening of plastics and of polyester fibres.

Bis-benzoxazolyl-compounds

2-Styrylbenztriazoles of the formula ##STR1## in which R denotes C.sub.1 -C.sub.4 -alkyl, benzyl or C.sub.1 -C.sub.4 -alkoxyethyl are suitable for whitening organic materials.

Whiteners, their preparation and use

Pyrazoline compounds of the formula ##STR1## wherein R represents C.sub.3 -C.sub.20 -alkyl and X, Y and Z independently of one another represent hydrogen, halogen, C.sub.1 -C.sub.4 -alkyl, trifluoromethyl, C.sub.1 -C.sub.4 -alkoxy, aryl or acylamino, are useful as optical brighteners for macromolecular materials.

Optical brighteners

2-Aryl-v-triazoles are obtained by reacting .alpha.-oximinoaryl-hydrazones of the formula ##EQU1## IN WHICH Ar represents an aromatic-carbocyclic or aromatic-heterocyclic radical, R.sub.1 denotes alkyl, aryl or nitro, R.sub.2 denotes hydrogen, alkyl or aryl and n denotes the numbers 1 or 2 with at least 2 equivalents of an isocyanate or carbamic acid halide or with at least 1 equivalent of a pyrocarbonic acid ester.

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Cologne, Germany

Josef Schroeder