Allessa Gmbh

Clariant Corporation

Allessa Chemie Gmbh

Joachim Ritzer

Doris Neumann

Thomas Wessel

Berthold Schiemenz

Gunther Effenberger

Lars Bierer

A method is described for the catalytic hydrogenation of aromatic nitro compounds with hydrogen to the corresponding amines in the presence of a supported catalyst comprising platinum. The method is characterized in that the catalyst comprising platinum has been modified with a tungsten compound and with a phosphorus compound in an oxidation state of &#x3c;5. High yields and high selectivities are possible with the method.

Method for hydrogenating nitroaromatic systems with selected platinum catalysts

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 present invention relates to a process for preparing substituted benzoyl chlorides of the formula (1)where R, x and y have the meaning given below, which comprises reacting a benzaldehyde of the formula (2)where R, independently of each other, is identical or different and is an unsubstituted phenyl radical or a phenyl radical that is substituted by halogen, NO, CN, (C-C)alkyl or (C-C)alkoxy, or is halogen, NO, CN, NR', OR&#x2032;, SOR&#x2032;, SOOR&#x2032;, COR&#x2032; or COR&#x2032;, where R&#x2032; is an unbranched or branched C-Calkyl radical, an unsubstituted phenyl radical or a phenyl radical which is substituted by halogen, NO, CN, (C-C)alkyl or (C-C)alkoxy, x is 1 or 2 and y is 1, 2 or 3, with a chlorinating agent in the presence of a free-radical initiator and a solvent at from &#x2212;20 to +200&#xb0; C.

Process for preparing substituted benzoyl chlorides

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Rodenbach, Germany

Joachim Ritzer