- AN IMPROVED PROCESS FOR THE PREPARATION OF DULOXETINE HYDROCHLORIDE
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The present disclosure provides solution to the problem associated in the preparation of duloxetine hydrochloride. This disclosure is successful in preventing the racemization and thereby prevents the formation of unwanted isomer of duloxetine hydrochloride. In addition, the disclosure provides a simple technique for removal of unreacted reactant, 1-fluoronapthalene used as a reactant in the process to obtain (S)-(+)-N-methyl-3(1-naphthalenyloxy)-3-(2-thienyl)propanamine hydrochloride, compound of formula (VI).
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- Process for the preparation of enantiomerically pure 3-hydroxy-3-arylpropylamines and their optical stereoisomers
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The invention provides a process for the preparation of enantiomerically pure 3-hydroxy-3-arylpropylamines via novel semiester derivatives containing o-carboxy benzoyl group as intermediates. The 3-hydroxy-3-arylpropylamines serve as precursor for the preparation of serotonin or noradrenalin reuptake inhibitors such as duloxetine, atomoxetine, fluoxetine, nisoxetine and norfluoxetine.
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Page/Page column 8
(2009/06/27)
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- Process for making duloxetine and related compounds
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A compound of formula 10 is useful in making duloxetine.
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Page/Page column 7
(2008/12/06)
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- Process for the Preparation of 1-Naphthol Mixed Ethers and Intermediates of Crystalline Forms of (+) and (-)-Duloxetine
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The invention relates to a process for the preparation of duloxetine (1a), comprising the reaction between 1-fluoronaphthalene and 3-N,N-dimethylamino-1-(2-thienyl)-propan-1-ol in the presence of 1,3-dimethyl-2-oxo-hexahydropyrimidine (DMPU) as the solvent; a method for the identification of duloxetine enantiomers and for the determination of its optical purity is also disclosed.
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Page/Page column 3
(2008/12/09)
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- NOVEL PROCESS FOR PREPARATION OF DULOXETINE HYDROCHLORIDE
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An improved, safer and easy to operate on plant scale process for synthesis of duloxetine hydrochloride (1) having chiral purity greater than 99.9% that is characterized by the following: (i) preparation of racemic condensed compound (RS)-N,N-di methyl-3- (1-naphthyloxy)-3-(2-thienyl)propanamine (4) by reaction of racemic hydroxy compound (2) with 1-fluronaphthalene (3) in presence of a base such as sodamide, potassium amide or potassium bis(trimethylsilyl)amide (KHDMS) in polar aprotic solvent, (ii) optical resolution of racemic condensed compound (5a + 5b) with di-benzoyl-L-tartaric acid (7, DBTA, R = H) or di-para-anisoyl-L-tartaric acid (7, DATA, R = OCH3) to obtain crude (S)-N.N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propanamine dibenzoyl tartarate salt (8a) or (S)-N.N-dimethyl-3-(1-naphthyloxy)-3-(2-thienyl)propanamine di-p-anisoyl tartarate salt (9a) respectively, (iii) optionally purification of crude tartarate salts (8a or 9a) by crystallization, (iv) optionally purification of duloxetine hydrochloride (1) by crystallization and (v) racemization of undesired (R)-N,N-di methyl-3-(1-naphthyloxy)-3-(2-thienyl)propanamine (5b) by treatment with base potassium bis(trimethylsilyl)amide (KHDMS) to obtain racemic mixture of condensed compounds (5a and 5b). A novel salt S(+)-N.N-dimethyl-3-(1-naphthylenyloxy)-3-(2-thienyl)propanamine dibenzoyl -(L)- tartarate (8a) and S(+)-N.N-dimethyl-3-(1-naphthylenyloxy)-3-(2-thienyl)propanamine di-p-anisoyl-(L)- tartarate (9a). Novel process for racemization of undesired (R)-N,N-di methyl-3-(1-naphthyloxy)-3-(2-thienyl)propanamine (5b) by treatment with KHDMS to obtain racemic mixture condensed compounds (5a and 5b).
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Page/Page column 25
(2008/12/07)
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- IMPROVED PROCESS FOR PURE DULOXETINE HYDROCHLORIDE
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A process for the preparation of pure Duloxetine hydrochloride comprises the steps of : a) reacting 1-(thiophen-2-yl)ethanone with dimethylamine hydrochloride, b) purifying the component in a solvent, c) reducing the component with an alkali metal borohydride, d) resolving the compound with a chiral acid, and treating the obtained compound with weak inorganic base, e) reacting the compound to give Duloxetine oxalate salt and f) converting the Duloxetine salt into its hydrochloride salt. Further the purifications of the obtained compound and of two intermediate products are described.
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Page/Page column 17
(2008/06/13)
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- A process for the preparation of an intermediate useful for the asymmetric synthesis of (+)duloxetine
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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.
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Page/Page column 5
(2010/11/28)
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