Preparation of biperiden used for treating Parkinson's disease by reacting diphenylmagnesium and bicycloheptenenyl-substituted propanone of high exo/endo ratio

摘要

Preparation of biperiden (I; a mixture of 1-(bicyclo(2,2,1)hept-5-en-2-yl(exoR))-1-phenyl-3-piperidinopropanol (1,S) and the corresponding (exoS)/(1,R) compound) comprises reacting a mixture of 1-(bicyclo(2,2,1)-hept-5-en-2-yl)-3-piperidino-1-propanone (II) having exo/endo ratio of at least 2.5:1 with diphenylmagnesium (DPM) and recovering (I) from the resulting mixture of isomers. An Independent claim is also included for (II) having an exo/endo ratio of 2.5-4:1.