Patent ID: 7030247
Filing Date: 2006-04-18
Classification: C07D

Abstract:
1. A method for producing biperiden by reacting an exo/endo mixture of 1-(bicyclo-[2.2.1]hept-5-en-2-yl)-3-piperidino-1-propanone with an exo/endo ratio of at least 2.5:1 with a phenylmagnesium compound to give a biperiden-containing mixture of isomers of 1 -(bicyclo-[2 .2.1]hept-5-en-2-yl)-1-phenyl-3-piperidino-1 -propanol, characterized in that the isolation of biperiden from the mixture of isomers comprises the following steps: a) reacting the mixture of isomers with HC1 in a mxture of water and a polar, water-miscible organic solvent, and isolation of the hydrochloride formed thereby, b) reacting the hydrochloride with heating in a mixture of water and at least one polar dialkyl ether of limited or zero miscibility with water and having 4 to 8 C atoms with a base, c) separating the two phases formed at elevated temperature, d) evaporating part of the ether from the organic phase and e) crystallizing of the biperiden by cooling.