| abstract |
The present invention relates to an improved process for racemizing one of the enantiomers, or an enantiomerically enriched mixture, of an optically active compound (S)- N , N -dimethyl-3-(2-thienyl)-3-hydroxypropanamine, a key intermediate used for the preparation of ( S )- N -methyl-3-(1-naphthalenyloxy)-3-(2- thienyl) propanamine (duloxetine) or its hydrochloride salt. Moreover, the present invention also relates to an improved process for the preparation of ( S )- N -methyl-3- (1-naphthalenyloxy)-3-(2-thienyl) propanamine (duloxetine) or its hydrochloride salt having low content of undesired R-isomer and chiral purity not less than 99%. |