Clariant Corporation

Cassella Aktiengesellschaft

Allessa Gmbh

Gunther Effenberger

Hubert Kruse

Joachim Ritzer

Doris Neumann

Detlef Wehle

Michael Roos

Dietmar Breier

Jens Ruppert

Jürgen Beyer

Olaf Just

A method for hydrogenating optionally substituted phenols with one hydroxyl group to cyclohexanones over modified, palladium-comprising supported catalysts. This is possible surprisingly in selected alcoholic solvents with high selectivity. Here it is even possible to recycle the catalysts employed, which hitherto has only been possible with considerable loss of selectivity.

Method for preparing cyclic ketones

The invention relates to a method for producing a phenothiazine granulate with a narrow particle size distribution. At least 98% pure phenothiazine in liquid form is pressed through a device provided with boreholes and a frequency is applied to said liquid phenothiazine. The liquid phenothiazine discharged through the boreholes enters a cooling medium having a temperature of between &#x2212;196 and +120&#xb0; C. The drops of liquid phenothiazine thus produced are brought to a temperature below melting point and are optionally solidified in another post-cooling area. Optionally, fine-grain particles or coarse-grained particles thus formed can be subsequently removed by appropriate methods. The bulk density of the obtained phenothiazine granulates ranges more particularly from 720&#x2013;780 kg/m.

Process for producing phenothiazine granules

In the process for the preparation of the dyestuff of the formula I ##STR1## by diazotization and coupling, the aqueous suspension present when the coupling has ended is heated to temperatures of 50.degree. C. up to the boiling point of the aqueous phase in the presence of a dispersing agent.

Process for the preparation of new crystal modification of an azo

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Bad Vilbel, Germany

Gunther Effenberger