Patent ID: 8530701
Filing Date: 2013-09-10
Classification: A61K,A61P,C07C

Abstract:
1. A process for producing a 2-[4-(3- or 2-fluorobenzyloxy)benzylamino]propanamide compound selected from wherein safinamide (Ia), ralfinamide (Ib), the respective R-enantiomer (I′a) or (I′b), or the respective racemic mixture (Ia, I′a) and (Ib, I′b) or a salt thereof with a pharmaceutically acceptable acid has a content of the respective impurity, which is lower than 0.03% by weight, characterized in that a Schiff base intermediate of formula (IIa), (IIIb) (i) is obtained by an iminoalkylation reaction of 4-(3- or 2-fluorobenzyloxy)benzaldehyde with L-alaninamide or D-alaninamide or the racemic mixture thereof, (ii) after completion of the iminoalkylation reaction, is submitted to a reduction reaction with a reducing agent selected from sodium borohydride and potassium borohydride (iii) the process being further characterized in that the 4-(3- or 2-fluorobenzyloxy)benzaldehyde starting material employed for the preparation of the Schiff base intermediate (IIIa), (IIIb), (III′a), (III′b) or the respective racemic mixture (IIIa, III′a) or (IIIb, III′b) has a content of 3-(3- or 2-fluorobenzyl)-4-(3- or 2-fluorobenzyloxy)benzaldehyde impurity lower than 0.03% by weight; whereby safinamide (Ia), ralfinamide (Ib), the respective R-enantiomer (I′a) or (I′b) or the respective racemic mixture (Ia, I′a) or (Ib, I′b) is obtained in a free base form and optionally, said free base form is converted to a salt thereof with a pharmaceutically acceptable acid.