摘要 |
Disclosed is a method for producing (-)cis-3-hydroxy-1-methyl-4-(2,4,6-trimethoxyphenyl)-piperidine characterised 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 1,3,5trimethoxybenzol 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-alcahol 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 3,4cis alcohol.
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