Biperideno production process.

Process for the preparation of biperiden of formula (Ia) (See formula) through the reaction of the exo / endo mixture of 1- (bicyclo [2.2.1] hept-5-en-2-yl) -3- piperidino-1-propanone (II) in an exo / endo of at least 2.5: 1 ratio, with a compound of phenylmagnesium resulting in a mixture of isomers of 1- (bicyclo [2.2.1] hept-5- en-2-yl) -1-phenyl-3-piperidino-1-propanol (I) containing biperiden, characterized in that the isolation of biperiden (Ia) contained in the isomer mixture comprises the following steps: a) conversion mixture of isomers with HC1 in a mixture of water and a water miscible polar organic solvent and isolation of the hydrochloride obtained in it, b) conversion of the hydrochloride under heating, with a base in a mixture of water and at least one dialkyl ether polar limitedly water miscible or water immiscible with 4 to 8 C atoms, c) Separation of the two phases formed hot, d) Evaporation n of a part of the ether from the organic phase and e) Crystallization of biperiden (Ia) by cooling.