The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 20, 2002
Filed:
Apr. 27, 2001
Gerhard Breipohl, Frankfurt, DE;
Jürgen Michalowsky, Kelkheim, DE;
Aventis Pharma Deutschland GmbH, Frankfurt am Main, DE;
Abstract
Disclosed is a method for producing (−)cis-3-hydroxy-1-methyl-4-(2,4,6-trimethoxyphenyl)-piperidine characterized in that 1-methyl-piperidine-4-one is converted into hydrobromide, subsequently transformed with bromine into 3(R,S)-bromine-1-methyl-4-oxo-piperidine-hydrobromide and reacted with 1,3,5-trimethoxybenzol to form 3(R,S)-bromine-1-methyl-4-(2,4,6-trimethoxyphenyl)-1,2,3,6-tetrahydro-pyridine-hydrobromide. By stirring the reaction solution into an organic solvent, 3(R,S)-bromine-1-methyl-4-(2,4,6-trimethoxyphenyl)-1,2,3,6-tetrahydro-pyridine-hydrobromide is initially isolated as a solid and subsequently the product is mixed with water and converted into 3(R,S)-hydroxy-1-methyl-4-(2,4,6-trimethoxyphenyl)-1,2,3,6-tetrahydro-pyridine by means of stirring. The product thus prepared is catalytically hydrogenated into a racemic 3,4-cis-alcohol and subsequently, enantiomerically pure (−)cis-3-hydroxy-1-methyl-4-(2,4,6-trimethoxyphenyl)-piperidine is obtained by separation of racemic mixtures with chiral auxiliary reagents from racemic 3,4-cis alcohol.