Zentiva K.s.

Josef Cinibulk

Ludek Ridvan

Lukas Placek

Kamal Jarrah

Monika Zatopkova

Stanislav Radl

Ivo Strelec

A method for the preparation of a duloxetine hydrochloride salt from a duloxetine base, comprising the steps of: reacting duloxetine base with concentrated hydrochloric acid in ethylmethylketone; and crystallizing duloxetine hydrochloride salt from said concentrated hydrochloric acid in ethylmethylketone.

Method for the preparation of (S)-N-methyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine hydrochloride (duloxetine)

A method of preparation of (S)-N-methyl-3-(1-naphthyloxy)-3-(2-mienyl)propylamine of Formula (I) and its pharmaceutically acceptable salts, comprising a) reaction of (RS)-N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine with optically active D-tartaric acid or an acid salt derived from D-tartaric acid forming a mixture of diastereoisomeric salts of N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine and D-tartaric acid (2:1), b) isolation of the salt (S)-N,N-dimethyl-3-(naphthyloxy) -3-(2-thienyl)propylamine/D-tartrate (2:1) from the mixture of diastereoisomeric salts in an organic solvent, water or a mixture thereof and release of (S)-N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine by action of an inorganic or organic base, c) demethylation of (S)-N,N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propylamine by action of an alkylchloroformate of formula ClCOOR (R=C-Calkyl, or C-Caryl or alkylraryl), especially phenyl, ethyl or methyl chloroformate, and d) hydrolytic release of the duloxetine base of formula I and optionally conversion of the base to a salt with the respective acid, or salt of a weak base. 

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Prague, Czechia

Josef Cinibulk