Hoechst Aktiengesellschaft

Walter Kunstmann

Joachim Ribka

Bernhard Mees

Wolfgang Rieper

1,2,4-TRIAMINO BENZENES ARE OBTAINED IN HIGH YIELD AND PURITY BY CATALYTIC HYDROGENATION OF 2,4-DINITRO ANILINES IN WATER CONTAINING AT LEAST ONE MOLAR EQUIVALENT OF A MONO- OR DI-CARBOXYLIC ACID. The products are known and useful as intermediates for dyes and biocides.

Process for the preparation of triamino benzenes by catalytic

Monoazo compounds obtained by diazotising meta- or para-acylamino anilines and coupling on acetoacetylamino benzimidazolones are pigments of excellent fastness properties.

Monoazo pigments from diazotized acylamino-anilines and acetoacetylamino

Pigments of the general formula ##STR1## wherein x is sulfur, oxygen or --NR--, R is hydrogen or alkyl of 1 to 4 carbon atoms, A is ##STR2## Y.sub.1, Y.sub.2, Z.sub.1, Z.sub.2, Z.sub.3, Z.sub.4, Z.sub.5, Z.sub.6 and Z.sub.7 are hydrogen, chlorine, bromine, methyl, ethyl, methoxy or ethoxy. These new disazo pigments can be used in all fields of dyeing where pigments are typically used. They are distinguished by improved fastness properties and tinctorial strength.

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Neuenhain, Taunus, Germany

Walter Kunstmann