Bayer Aktiengesellschaft

Lanxess Deutschland Gmbh

Bayer Healthcare Aktiengesellschaft

Kernforschungsanlage Julich Gesellschaft MIT Beschrankter Haftung

Herbert Diehl

Karlfried Wedemeyer

Heinz U Blank

Reinhold Gehring

Andreas Krebs

Klaus Mohrs

Georg Martin

Edwin Ritzer

Werner Heilmann

Rolf Grosser

Franz-Josef Mais

Gerhard Franckowiak

Hanns-Ingolf Paul

Paul Naab

Walter Lange

Josef Kasbauer

Guido Giffels

Gerold Schade

Hans-Peter Wirges

Mathias Berwe

Joachim Komoschinski

Erich Hammerschmidt

Rudolf Zerbes

Peter P Wenzl

Lutz Frohn

Heinrich Pelster

Karl-Heinz Wahl

Karl-Wilhelm Henneke

Dietrich Seidel

Joachim Westen

Bettina Hölzer

Wilfried Jaworek

Tobias Reichelt

Hubert Habetz

Friedrich Dürrholz

Karl Rittner

Elvira Krebs, Legal Representative

The present invention relates to a process for the enantiomeric enrichment of cis-8-benzyl-7,9-dioxo-2,8-diazabicyclo[4.3.0]nonane with the aid of continuous countercurrent chromatography, which is also described as SMB chromatography (SMB=simulated moving bed). In a further aspect, the invention relates to a process for the preparation of (1S,6R)-8-benzyl-7,9-dioxo-2,8-diazabicyclo[4.3.0]nonane using the aforementioned process, which furthermore includes a racemization step.

Process for the enantiomeric enrichment of cis-8-benzyl-7,9-dioxo-2,8-diazabicyclo[4.3.0]nonane

An improved process for preparing carbamic ester derivatives of the general formula (1) by reaction with carbon monoxide and water in the presence of a palladium catalyst is provided.

Process for preparing carbamic ester derivatives

The invention relates to a special two-step method for producing amines on the basis of amides by reacting them with halides or hypohalites in an aqueous solution in a Hofmann degradation reaction. The amide is reacted in an alkaline solution and/or suspension with halides or hypohalites and the reaction mixture obtained in step 1 is added to an aqueous alkaline solution having a temperature of at least 40&#xb0; C.

Method of producing amines

The present invention relates to a novel process for preparing 8-methoxy-3-quinolonecarboxylic acids which are antibiotics having potent antibacterial action.

Method for producing 8-methoxy-quinolinecarboxylic acids

The present invention describes a process for preparing 4-amino-1-naphthol ethers which is characterized in that naphthol ethers are first prepared from 1-naphthols, the former are then converted to the corresponding 4-acetamino-1-naphthol ethers and then the acyl group is cleaved off, and further describes 4-acetamino-1-naphthol ethers obtained thereby.

Preparation of 4-amino-1-naphthol ethers

Piperidines are prepared in an advantageous manner by catalytic hydrogenation of activated pyridines in the presence of palladium catalysts if the palladium catalyst is palladium-on-carbon and the solvents are aromatic hydrocarbons.

Process for preparing piperidines

Cis-R-dioxo-benzylpyrrolopiperidine is racemized in a particularly advantageous manner by treating it with a substoichiometric amount of base, preferably at temperatures below about 40&deg; C.

Racemization of R,S-dioxo-benzylpyrrolopiperidine

3-Hydroxybenzyl alcohol can be prepared in a simple and inexpensive way by subjecting 3-chloromethylphenyl chloroformate to an acidolysis with a carboxylic acid or a carboxylic acid salt and subsequently subjecting the reaction product of the first step to an alcoholysis.

Process for preparing 3-hydroxybenzyl alcohol

The invention relates to a process for the preparation of nifedipine by the reaction of methyl 2-(2-nitrobenzylidene)acetoacetate and methyl 3-aminocrotonate and the use of the nifedipine thus prepared for the production of a medicament.

Process for preparing nifedipine

The present invention relates to a one-pot process for the preparation of 7-heterocyclyl-substituted 3-quinolonecarboxylic acid derivatives. They possess a strong anti-microbial effect. They include active compounds such as, for example, ofloxacin, ciprofloxacin or enrofloxacin.

One-pot process for the preparation of 3-quinolonecarboxylic acid

Cyclopropanecarboxamide can be prepared by reaction of a cyclopropanecarboxylic ester with NH.sub.3, in which the ester alcohol has 4-8 C atoms and can be straight-chain or branched and which process is carried out in the presence of catalytic amounts of an alkali metal alcoholate of a monohydric C.sub.1-C.sub.8 alcohol at 60.degree.-200.degree. C. in the absence of a hydrocarbon solvent.

Process for the preparation of cyclopropanecarboxamide

The present process for the preparation of cyclopropylamine by the so-called Hofmann degradation of cyclopropanecarboxamide is characterized in that the cyclopropanecarboxamide is employed in the form of a solution. The new process can be carried out at 5.degree.-35.degree. C. The cyclopropylamine is obtained after introducing the reaction mixture into a concentrated alkali metal hydroxide solution.

Process for the preparation of cyclopropylamine

The present invention relates to the preparation of thiocyanatomethylthiobenzothiazoles by the reaction of halomethylthiobenzothiazoles with thiocyanates at elevated temperature in aqueous solution in the presence of a phase transfer catalyst.

Process for the preparation of thiocyanatomethylthiobenzothiazoles

5-Fluorotoluene-2,4-disulphochloride is prepared by chlorosulphonation of 3-fluorotoluene by first reacting the 3-fluorotoluene with chlorosulfuric acid and then with an inorganic acid chloride at temperatures up to 130.degree. C. until the evolution of gas is complete, and then heating the reaction mixture at temperatures of up to 200.degree. C. and, after the completion of the gas evolution, reacting the product at a lower temperature with further inorganic acid chloride, or reacting the 3-fluorotoluene with powerful sulphonating agents at an elevated temperature, if appropriate in the presence of inert solvents and/or diluents, to give the corresponding disulphonic acid and then treating the disulphonic acid with inorganic acid chlorides.

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Leverkusen, Germany

Herbert Diehl