A process for the preparation of an intermediate useful for the asymmetric synthesis of (+)duloxetine

摘要

A process for the preparation of (+)duloxetine, or an acid addition salt thereof, comprising:
(i) Resolving racemic (±)N-methyl duloxetine with a less than stoichiometric amount of a chiral acid in combination with suitable amounts of a hydrohalogen acid to give a salt of the chiral acid and (+)N-methyl duloxetine, substantially free from (-)N-methyl duloxetine;
(ii) Demethylating the (+)N-methyl duloxetine prepared in step (i) to give (+)duloxetine or another acid addition salt in enantiomerically pure form.