- A west Luo river sandbank chiral intermediate mandelic acid salt preparation method
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A purpose of the present invention is to provide a method for simultaneously recycling (R)-(-)-N,N-dimethyl-3-(2-thienyl)-3-hydroxypropylamine (II) and S-mandelic acid to prepare a duloxetine chiral intermediate (S)-(-)-N,N-dimethyl-3-(2-thienyl)-3-hydroxypropylamine S-mandelate (I). The formulas (I) and (II) are defined in the instruction.
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Paragraph 0037; 0041-0045
(2017/07/19)
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- Preparation method of (S)-3-N,N-disubstituted amino-1-(2-thienyl)-1-propanol
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The invention discloses a preparation method of (S)-3-N,N-disubstituted amino-1-(2-thienyl)-1-propanol shown as the formula (I). The method comprises: taking 2-acetyl thiophene shown in the formula (II) as a raw material, and allowing 2-acetyl thiophene to completely react with di(trichloromethyl)carbonic ester (III) and N,N-disubstituted methanamide (IV) in an organic solvent under the catalysis of an organic base to obtain N,N-disubstituted amino-1-(2-thienyl)-1-acrylketone shown as the formula (V); and performing hydrogenation reduction with lithium aluminium hydride to obtain N,N-disubstituted amino-1-(2-thienyl)-1-propanol shown as the formula (VI); and performing splitting with S-mandelic acid and recrystallization with ethyl acetate to obtain the target product shown as the formula (I). The preparation method is low in cost, mild in reaction condition, less in waste water, waste gas and industrial residue, small in energy consumption, and high in yield. The preparation method is safe and is suitable for industrial production.
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Paragraph 0043; 0044
(2018/03/24)
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- Chemoenzymatic synthesis of (S)-duloxetine using carbonyl reductase from Rhodosporidium toruloides
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A chemoenzymatic strategy was developed for (S)-duloxetine production employing carbonyl reductases from newly isolated Rhodosporidium toruloides into the enantiodetermining step. Amongst the ten most permissive enzymes identified, cloned, and overexpressed in Escherichia coli, RtSCR9 exhibited excellent activity and enantioselectivity. Using co-expressed E. coli harboring both RtSCR9 and glucose dehydrogenase, (S)-3-(dimethylamino)-1-(2-thienyl)-1-propanol 3a was fabricated with so far the highest substrate loading (1000 mM) in a space-time yield per gram of biomass (DCW) of 22.9 mmol L-1 h-1 g DCW-1 at a 200-g scale. The subsequent synthetic steps from RtSCR9-catalyzed (S)-3a were further performed, affording (S)-duloxetine with 60.2% overall yield from 2-acethylthiophene in >98.5% ee.
- Chen, Xiang,Liu, Zhi-Qiang,Lin, Chao-Ping,Zheng, Yu-Guo
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- IMPROVED PROCESS FOR THE PREPARATION OF DULOXETINE AND ITS PHARMACEUTICALLY ACCEPTABLE SALT
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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%.
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Page/Page column 20
(2011/04/19)
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- AN IMPROVED PROCESS FOR THE PREPARATION OF DULOXETINE AND SALTS THEREOF
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The present invention relates to improved process for the preparation of Duloxetine of formula (I) and salts thereof wherein said improvement takes place in step of condensation.
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Page/Page column 7
(2010/08/04)
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- PROCESS FOR THE PREPARATION ENANTIOMERICALLY PURE SALTS OF N-METHYL-3-(1-NAPHTHALENEOXY)-3-(2-THIENYL)PROPANAMINE
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The present invention relates to duloxetine salts having enantiomeric purity of 98% or more and a process for such salts.
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Page/Page column 3
(2010/12/29)
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- PROCESS FOR THE PREPARATION OF 3-ARYLOXY-3-ARYLPROPANAMINES
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The present invention provides a process for the preparation of 3-aryloxy-3-arylρropanamine derivatives. Particularly the present invention provides a process for the preparation of duloxetine and pharmaceutically acid addition salts thereof specifically, duloxetine hydrochloride of formula (I), using 3-O-protected propanolamine derivatives. The invention also aims at providing a process for the preparation of highly pure duloxetine hydrochloride of formula (I) from duloxetine free base via its acid addition salts The invention further aims at providing a process for the purification of duloxetine hydrochloride, wherein the level of unwanted R-enantiomer is reduced to nearly 0%.
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Page/Page column 16-17
(2009/04/25)
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- AN IMPROVED PROCESS FOR THE SEPARATION OF ENANTIOMERICALLY PURE COMPOUNDS
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The present patent application relates to an improved process for the separation of enantiomerically pure compounds. Specifically it relates to separation of enantiomerically pure Rivastigmine, Duloxetine, Escitalopram and their intermediates in high yields.
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Page/Page column 20; 21
(2009/12/28)
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- PROCESS FOR THE PREPARATION OF DULOXETINE AND ITS SALTS
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The present invention relates to duloxetine salts having enantiomeric purity of 98% or more and a process for such salts.
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Page/Page column 7
(2008/06/13)
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- A PROCESS FOR PREPARATION OF (S)-(+)-N-METHYL-3(1-NAPHTHYLOXY)-3(2-THIENYL)PROPYLAMINE HYDROCHLORIDE
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The present invention provides an improved process for preparation of intermediate of Duloxetine base and hydrochloride salt thereof.
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Page/Page column 10-11
(2008/12/07)
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- Process for the preparation of (S)-(-)-N,N-dimethyl-3-(2-thienyl)-3-hydroxypropananine, a duloxetine intermediate
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A chiral resolution process for the preparation of (S)-AT-OL, and a process for the racemization of AT-OL are provided.
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Page/Page column 6
(2008/06/13)
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- Process for preparing duloxetine and intermediates thereof
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Processes for preparing chemically pure duloxetine and chemically pure duloxetine intermediates are provided.
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Page/Page column 5
(2010/11/29)
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- Synthesis of (S)-3-(N-methylamino)-1-(2-thienyl)propan-1-ol: Revisiting Eli Lilly's resolution-racemization-recycle synthesis of duloxetine for its robust processes
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(±)-3-(N,N-Dimethylamino)-1-(2-thienyl)propan-1-ol (6), prepared from 2-acetylthiophene (4) in a two-step overall yield of 79%, is resolved into (S)-6 of 93% ee as its diastereomeric salt (8) with (S)-mandetic acid (7) according to Eli Lilly's procedures developed for the resolution-racemization- recycle (RRR) synthesis of duloxetine (2) with some modifications in terms of practicality. On its liberation from 8, (S)-6 undergoes N-demethylative ethyl carbamate formation in two discrete but successive steps in an overall yield of 87% from 8: (1) O-ethyl carbonate formation and (2) ethyl carbamate formation with concomitant loss of the N-methyl group. Alkaline hydrolysis then affords (S)-3-(N-methylamino)-1-(2-thienyl)propan-1-ol (1) of 100% ee, an alleged penultimate precursor to duloxetine (2), in 75% yield after a single recrystallization from ethylcyclohexane. In the overall process thus developed, PhMe is substituted successfully for t-BuOMe, a solvent that has been used favorably in Eli Lilly's original RRR synthesis of 2.
- Fujima, Yoshito,Ikunaka, Masaya,Inoue, Toru,Matsumoto, Jun
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p. 905 - 913
(2012/12/23)
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