Basf Se Corporation

Basf Aktiengesellschaft

Eike Johannes Bergner

Klaus Ebel

Gunnar Heydrich

Gabriele Gralla

Rocco Paciello

Wolfgang Krause

Matthias Rauls

Thorsten Johann

Nawid Kashani-Shirazi

Steffen Oehlenschläger

Joachim Schmidt-Leithoff

Marko Friedrich

Oliver Löber

Hartmut Hibst

Gerd Kaibel

Boris Breitscheidel

Klemens Massonne

Klaus Harth

Christian Walsdorff

Klaus Halbritter

Frank Haese

Christoph Jäkel

Ralf Noe

Melanie Maas-Brunner

Axel Salden

Christoph Jäkal

The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method has the following steps

Method for producing optically active, racemic menthol

The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method comprises the following steps a) catalytic hydrogenation of neral and/or geranial to give citronellal, b) cyclization of citronellal to isopulegol in the presence of an acidic catalyst, c) purification of isopulegol by crystallization and d) catalytic hydrogenation of isopulegol to give menthol.

The present invention relates to a process for preparing racemic or optically active menthol by catalytically hydrogenating racemic or optically active isopulegol in the presence of hydrogen and catalysts which comprise nickel-, copper-, zirconium- and molybdenum-containing compounds. The present invention relates specifically to a corresponding process far continuously catalytically hydrogenating L-isopulegol to L-menthol.

Process for preparation of menthol by hydrogenation of isopulegol

Processes comprising: (a) enantioselectively hydrogenating a staffing material comprising a component selected from geraniol, nerol and mixtures thereof to form optically active citronellol; (b) converting the optically active citronellol to optically active citronellal; (c) cyclizing the optically active citronellal to form a mixture comprising optically active isopulegol; and (d) subjecting the mixture to further processing comprising: (i) separating the optically active isopulegol from the mixture and hydrogenating the separated optically active isopulegol to form optically active menthol; or (ii) hydrogenating the optically active isopulegol in the mixture to form optically active menthol and separating the optically active menthol from the mixture.

Method for the production of menthol

The present invention relates to a process for preparing optically active aldehydes or ketones which have from 3 to 25 carbon atoms and at least one racemizable stereocenter by catalytic dehydrogenation of the corresponding optically active primary or secondary alcohols in the gas phase in the presence of a catalyst.

Method for producing optically active carbonyl compounds

The invention relates to a process for preparing cyclohexanedicarboxylic acids or derivatives thereof, such as esters and/or anhydrides, encompassing the reaction of diene/maleic acid anhydride mixtures, in particular of butadiene/maleic acid anhydride mixtures or of mixtures of maleic acid anhydrides and C5-dienes to give alkyl-substituted or unsubstituted cyclohexenedicarboxylic acid anhydrides in the condensed phase, ester formation, and then hydrogenation to give the corresponding cyclohexanedicarboxylic acid derivative, and also to the use of the cyclohexanedicarboxylic acids or derivatives thereof prepared according to the invention as plasticizers for plastics.

Method for producing cyclohexane dicarboxylic acids and the derivatives thereof

Growing community of inventors

Schriesheim, Germany

Eike Johannes Bergner