- A Photoswitchable Inhibitor of the Human Serotonin Transporter
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The human serotonin transporter (hSERT) terminates serotonergic signaling through reuptake of neurotransmitter into presynaptic neurons and is a target for many antidepressant drugs. We describe here the development of a photoswitchable hSERT inhibitor, termed azo-escitalopram, that can be reversibly switched between trans and cis configurations using light of different wavelengths. The dark-adapted trans isomer was found to be significantly less active than the cis isomer, formed upon irradiation.
- Cheng, Bichu,Ladefoged, Lucy Kate,Maesen, Jannick Bang,Morstein, Johannes,Schi?tt, Birgit,Sinning, Steffen,Trauner, Dirk
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Read Online
- Substrate modification approach to achieve efficient resolution: Didesmethylcitalopram: A key intermediate for escitalopram
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Research work presented here describes an approach to achieve the enantiopure escitalopram (1) via didesmethyl escitalopram (4), which is easily resolvable compared to citalopram (1a) through diastereomeric salt crystallization. The resolved intermediate (didesmethylcitalopram) was subsequently used for the preparation of the desired drug. This simple modification of the substrate makes a remarkable difference in the chemical resolution process. The first resolution of didesmethylcitalopram (±)-4 to furnish (+)-4, a novel key intermediate to assemble escitalopram (1) was achieved via diastereomeric salt resolution using (-)-di-p-toluoyltartaric acid (DPTTA). The resolution conditions were optimized; a key feature of this process is the addition of specific quantity of water at a specific temperature to the reaction mixture.
- Elati, Chandrashekar R.,Kolla, Naveenkumar,Vankawala, Pravinchandra J.,Gangula, Srinivas,Chalamala, Subrahmanyeswarara,Sundaram, Venkatraman,Bhattacharya, Apurba,Vurimidi, Himabindu,Mathad, Vijayavitthal T.
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Read Online
- Enzymatic resolution of a quaternary stereogenic centre as the key step in the synthesis of (S)-(+)-citalopram
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The enzymatic resolution of 4-[(4-dimethylamino)-1-(4′-fluorophenyl)- 1-hydroxy-1-butyl]-3-(hydroxymethyl)-benzonitrile, a useful intermediate in the synthesis of enantiomerically pure citalopram, has been studied. Candida antarctica lipase B (CAL-B) catalyzes the enzymatic acetylation of the primary benzylic alcohol with high enantioselectivity at the quaternary stereogenic centre. The enzymatic enantioselective hydrolysis of the 3-acetyloxymethyl derivative catalyzed by CAL-B is also possible.
- Solares, Laura F.,Brieva, Rosario,Quiros, Margarita,Llorente, Isidro,Bayod, Miguel,Gotor, Vicente
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Read Online
- Method for preparing citalopram and S - citalopram
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The invention relates to a method of preparing citalopram and S-citalopram by carrying out cyclization reaction on a diol compound (II) or S-diol compound (II') in a nixed solvent of a C4-C7 ketone solvent and water and aryl sulfonyl chloride or alkyl sulfonyl chloride under an alkaline condition. The solvent used by the invention is great in solubility to reactants and products, so that the use level of the solvent is reduced, the yield is improved and meanwhile the method is good in post-treatment extraction effect and simple and convenient to operate. The compounds (II and II') are as shown in the specification.
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Paragraph 0014; 0026-0027
(2021/07/01)
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- NEW SALT AND SOLID STATE FORMS OF ESCITALOPRAM
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The present disclosure relates to a new salt of escitalopram and its solid state forms, processes for the preparation thereof, pharmaceutical compositions thereof, and methods of use thereof.
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Paragraph 061
(2019/05/02)
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- PROCESS FOR PRODUCING HYDROBROMIDE OF DIOL COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for producing 4-[4-(dimethylamino)-1-(4-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)-benzonitrile hydrobromide with a high purity and a high isolation yield. SOLUTION: Provided is a process for producing 4-[4-(dimethylamino)-1-(4-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)-benzonitrile hydrobromide characterized in bringing 4-[4-(dimethylamino)-1-(4-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)-benzonitrile and hydrogen bromide into contact in a mixed solvent of an ester-based solvent and water. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
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Paragraph 0044
(2020/05/14)
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- Evaluation of the Edman degradation product of vancomycin bonded to core-shell particles as a new HPLC chiral stationary phase
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A modified macrocyclic glycopeptide-based chiral stationary phase (CSP), prepared via Edman degradation of vancomycin, was evaluated as a chiral selector for the first time. Its applicability was compared with other macrocyclic glycopeptide-based CSPs: TeicoShell and VancoShell. In addition, another modified macrocyclic glycopeptide-based CSP, NicoShell, was further examined. Initial evaluation was focused on the complementary behavior with these glycopeptides. A screening procedure was used based on previous work for the enantiomeric separation of 50 chiral compounds including amino acids, pesticides, stimulants, and a variety of pharmaceuticals. Fast and efficient chiral separations resulted by using superficially porous (core-shell) particle supports. Overall, the vancomycin Edman degradation product (EDP) resembled TeicoShell with high enantioselectivity for acidic compounds in the polar ionic mode. The simultaneous enantiomeric separation of 5 racemic profens using liquid chromatography-mass spectrometry with EDP was performed in approximately 3?minutes. Other highlights include simultaneous liquid chromatography separations of rac-amphetamine and rac-methamphetamine with VancoShell, rac-pseudoephedrine and rac-ephedrine with NicoShell, and rac-dichlorprop and rac-haloxyfop with TeicoShell.
- Hellinghausen, Garrett,Lopez, Diego A.,Lee, Jauh T.,Wang, Yadi,Weatherly, Choyce A.,Portillo, Abiud E.,Berthod, Alain,Armstrong, Daniel W.
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p. 1067 - 1078
(2018/08/01)
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- PRODUCTION METHOD OF (1S)-1-[3-(DIMETHYLAMINO)PROPYL]-1-(4-FLUOROPHENYL)-1,3-DIHYDROISOBENZOFURAN-5-CARBONITRILE OXALATE
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PROBLEM TO BE SOLVED: To provide a (1S)-1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5-carbonitrile (escitalopram) oxalate having extremely high optical purity and extremely little residual solvent. SOLUTION: The following production method is used: (1S)-1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5-carbonitrile oxalate, by 1 part by mass, is dissolved and heated in an organic solvent containing 8-15 parts by volume of ethanol, then the solution is cooled at a rate of at least 25°C/h or more to crystallize so as to obtain the oxalate as a crystallized product. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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- PRODUCTION METHOD OF (1S)-4-[4-(DIMETHYLAMINO)-1-(4'-FLUOROPHENYL)-1-HYDROXYBUTYL]-3-(HYDROXYMETHYL)-BENZONITRILE HEMI(+)-DI-(p-TOLUOYL) TARTRATE, AND PRODUCTION METHOD OF (1S)-1-[3-(DIMETHYLAMINO)PROPYL]-1-(4-FLUOROPHENYL)-1,3-DIHYDROISOBENZOFURAN-5-CARBONITRILE AND SALT THEREOF USING THE TARTRATE
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PROBLEM TO BE SOLVED: To provide a (1S)-4-[4-(dimethylamino)-1-(4'-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)-benzonitrile hemi(+)-di-(p-toluoyl) tartrate having extremely high optical purity, and escitalopram having extremely high optical purity and its salt obtained from the above tartrate. SOLUTION: A production method is used, in which a crude (1S)-4-[4-(dimethylamino)-1-(4'-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)-benzonitrile hemi(+)-di-(p-toluoyl) tartrate is recrystallized in a mixture solvent of alcohol and water, with the content of the water being 3.0 to 15.0 mass% in the mixture solvent of the alcohol and water, so as to obtain a recrystallized material of the above tartrate having extremely high optical purity. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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- PRODUCTION METHOD OF S-4-[4-(DIMETHYLAMINO)-1-(4'-FLUOROPHENYL)-1-HYDROXYBUTYL]-3-(HYDROXYMETHYL)-BENZONITRILE, AND PRODUCTION METHOD OF (1S)-1-[3-(DIMETHYLAMINO)PROPYL]-1-(4-FLUOROPHENYL)-1,3-DIHYDROISOBENZOFURAN-5-CARBONITRILE AND SALT THEREOF USING THE COMPOUND
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PROBLEM TO BE SOLVED: To provide a (1S)-4-[4-(dimethylamino)-1-(4'-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)-benzonitrile having extremely high chemical purity and optical purity, and escitalopram having extremely high optical purity and its salt obtained from the above compound. SOLUTION: The following production method is used: (1S)-4-[4-(dimethylamino)-1-(4'-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)-benzonitrile hemi(+)-di-(p-toluoyl) tartrate is made to react in a solvent comprising at least one sparingly water-soluble organic solvent selected from the group consisting of aromatic hydrocarbons and halogenated hydrocarbons, and water so as to obtain an educt of the tartrate. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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- PROCESS FOR PRODUCING (1S)-4-[4-(DIMETHYLAMINO)-1-(4'-FLUOROPHENYL)-1-HYDROXYBUTYL]-3-(HYDROXYMETHYL)-BENZONITRILE HEMI(+)-DI-(p-TOLUOYL) TARTARIC ACID SALT, AND PROCESS FOR PRODUCING (1S)-1-[3-(DIMETHYLAMINO)PROPYL]-1-(4-FLUOROPHENYL)-1,3-DIHYDRO-ISOBENZOFURAN-5-CARBO-NITRILE AND SALT THEREOF USING SAID TARTARIC ACID SALT
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PROBLEM TO BE SOLVED: To provide a production process in which (1S)-4-[4-(dimethylamino)-1-(4'-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)-benzonitrile hemi(+)-di-(p-toluoyl) tartaric acid salt that has extremely high chemical purity and optical purity is obtained in high yield. SOLUTION: Provided is a production process characterized in producing a tartaric acid salt as a crystallized product by reacting racemate 4-[4-(dimethylamino)-1-(4'-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)-benzonitrile with (+)-di-(p-toluoyl) tartaric acid to yield (1S)-4-[4-(dimethylamino)-1-(4'-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)-benzonitrile hemi(+)-di-(p-toluoyl) tartaric acid salt and followed by carrying out crystallization of the tartaric acid salt with a solvent containing 1-butanol. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPO&INPIT
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- NOVEL RECOVERY AND RECYCLING PROCESS OF RACEMIC 4-(4-DIMETHYLAMINO)-1-(4'-FLUOROPHENYL)-1-(HYDROXYBUTYL)-3-(HYDROXYMETHYL)-BENZONITRILE
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Disclosed herein is a novel recovery and recycling process of racemic 4-(4- dimethylamino)-1-(4'-fluorophenyl)-1-(hydroxybutyl)-3-(hydroxymethyl)- benzonitrile (hereinafter referred as cyanodiol). The racemic cyanodiol is an intermediate useful for preparation of Citalopram, Escitalopram or pharmaceutically acceptable salts thereof.
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Page/Page column 28; 29
(2017/02/09)
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- Synthesis method of aryl alcohol compound and Escitalopram
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The invention discloses a synthesis method of an aryl alcohol compound and Escitalopram. The synthesis method of the aryl alcohol compound comprises the following steps: under gas protection and in an organic solvent and in the presence of transition metal, diphosphine ligand and alkali, the compound of formula 1 reacts with an aryl boron reagent 2. The synthesis method of Escitalopram comprises the following steps: (1) under gas protection and in an organic solvent and in the presence of transition metal, diphosphine ligand and alkali, the compound of formula 4 reacts with the aryl boron reagent 2; (2) under gas protection and in an organic solvent and in the presence of alkali, the compound of formula 5 reacts with dimethylamine or hydrochloride thereof; (3) under gas protection and in an organic solvent and in the presence of organic phosphine ligand and a palladium catalyst, the compound of formula 7 reacts with metal cyanide; and (4) under gas protection and in an organic solvent and in the presence of a reducing agent, the compound of formula 6 reacts. The synthesis method disclosed by the invention has high yield and enantioselectivity.
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Paragraph 0155
(2016/10/10)
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- PROCESS FOR THE CYCLODEHYDRATION OF DIOLS AND USE THEREOF FOR THE MANUFACTURING OF AMBRAFURAN AND OTHER CYCLOETHER DERIVATIVES
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The present invention relates to a process for manufacturing tetrahydrofuran, tetrahydropyran and, more generally, cycloether derivatives through the cyclodehydration of 1,4- or 1,5- diols. More specifically, the process of the invention involves (i) the stereoselective cyclodehydration in water of 1,4- or 1,5- diols comprising at least one chiral tertiary alcohol functional group with retention of the initial chirality, and/or (ii) the cyclodehydration in water of 1,4- or 1,5- diols, said diols being non-miscible with and/or non-soluble in water, into corresponding cycloether derivatives, by bringing the reaction mixture to high temperature water (HTW) conditions and/or by mixing the aqueous reaction mixture with a solid catalyst, such as for example a smectite clay. The present invention further relates to the use of the process of the invention for manufacturing ambrafuran, especially (-)-ambrafuran and other cycloether derivatives.
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Page/Page column 50
(2013/03/26)
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- PROCESS FOR THE PURIFICATION OF PHARMACEUTICALLY ACCEPTABLE SALTS
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The present invention is concerned with a process in connection with the purification of a pharmaceutically acceptable salt of escitalopram or citalopram.
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Page/Page column 10-11
(2012/02/05)
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- CRYSTALLINE BASE OF ESCITALOPRAM AND ORODISPERSIBLE TABLETS COMPRISING ESCITALOPRAM BASE
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The present invention relates to the crystalline base of the well known antidepressant drug escitalopram, S -1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzo-furancarbonitrile, formulations of said base, a process for the preparation of purified salts of escitalopram, such as the oxalate, using the base, the salts obtained by said process and formulations containing such salts, and a process for the preparation of purified escitalopram free base or salts of escitalopram, such as the oxalate, using the hydrobromide, the salts obtained by said process and formulations containing such salts. Finally the present invention relates to an orodispersible tablet having a hardness of at least 22 N and an oral-disintegration time of less than 120 s and comprising an active pharmaceutical ingredient adsorbed onto a water soluble filler wherein the active pharmaceutical ingredient has a melting point in the range of 40-100 °C, as well as a method for making such an orodispersible tablet.
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Page/Page column 6; 8-9
(2011/02/25)
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- Preparation of Escitalopram, Its Salts and Intermediates
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The present patent application relates to an improved process for the preparation of escitalopram, its salts and intermediates. It also relates to a novel crystalline form S of citalopram diol intermediate, process for preparation and its use in the preparation of citalopram, escitalopram and their salts.
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Page/Page column 6
(2011/05/03)
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- Enantioenriched synthesis of Escitalopram using lithiation-borylation methodology
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The asymmetric synthesis of Escitalopram has been completed using a lithiation-borylation reaction as the key step. Suitably functionalized enantioenriched carbamate (er 98:2) and boronic ester coupling partners were prepared and following deprotonation with s-BuLi and borylation, the tertiary alcohol was obtained in 42% yield and 93:7 er. The lithiation-borylation reaction was found to tolerate nitrile, benzylic alcohol and N-Boc functionalities. The tertiary alcohol was converted to Escitalopram in three further steps.
- Partridge, Benjamin M.,Thomas, Stephen P.,Aggarwal, Varinder K.
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supporting information; experimental part
p. 10082 - 10088
(2012/02/05)
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- PREPARATION OF ESCITALOPRAM, ITS SALTS AND INTERMEDIATES
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The present patent application relates to an improved process for the preparation of escitalopram, its salts and intermediates. It also relates to a novel crystalline form S of citalopram diol intermediate, process for preparation and its use in the preparation of citalopram, escitalopram and their salts.
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Page/Page column 18
(2010/04/03)
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- Process for the Preparation of Escitalopram
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The present invention provides a novel process for the preparation of a compound of Formula III, and novel processes for preparing escitalopram using the compound of Formula III.
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Page/Page column 8
(2010/08/18)
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- Structure-activity relationships for a novel series of citalopram (1-(3-(dimethylamino)propyl)-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5- carbonitrile) analogues at monoamine transporters
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(±)-Citalopram (1, 1-(3-(dimethylamino)propyl)-1-(4-fluorophenyl)-1, 3-dihydroisobenzofuran-5-carbonitrile), and its eutomer, escitalopram (S-(+)-1) are selective serotonin reuptake inhibitors (SSRIs) that are used clinically to treat anxiety and depression. To further explore structure-activity relationships at the serotonin transporter (SERT), a series of (±)-4- and 5-substituted citalopram analogues were designed, synthesized, and evaluated for binding at the SERT, dopamine transporter (DAT) and norepinephrine transporter (NET) in native rodent tissue. Many of these analogues showed high SERT binding affinities (Ki = 1-40 nM) and selectivities over both NET and DAT. Selected enantiomeric pairs of analogues were synthesized and both retained enantioselectivity as with S- and R-1, wherein S > R at the SERT. In addition, the enantiomeric pairs of 1 and 5 were tested for binding at the homologous bacterial leucine transporter (LeuT), wherein low affinities and the absence of enantioselectivity suggested distinctive binding sites for these compounds at SERT as compared to LeuT. These novel ligands will provide molecular tools to elucidate drug-protein interactions at the SERT and to relate those to behavioral actions in vivo.
- Zhang, Peng,Cyriac, George,Kopajtic, Theresa,Zhao, Yongfang,Javitch, Jonathan A.,Katz, Jonathan L.,Newman, Amy Hauck
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experimental part
p. 6112 - 6121
(2010/11/16)
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- PREPARATION OF ESCITALOPRAM
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A substantially pure (S)-4-[4-(dimethylamino)-1-(4′-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)benzonitrile intermediate for preparing escitalopram is prepared by: a) combining racemic (±)-4-[4-(dimethylamino)-1-(4′-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)benzonitrile with (?)-di-p-toluoyltartaric acid, in a solvent; b) separating a solid phase comprising a salt of (?)-di-p-toluyltartaric acid with (R)-4-[4-(dimethylamino)-1-(4′-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)benzonitrile enantiomer, and a liquid phase comprising a salt of (?)-di-p-toluoyltartaric acid with (S)-4-[4-(dimethylamino)-1-(4′-fluorophenyl)-1-hydroxy-butyl]-3-(hydroxymethyl)benzonitrile enantiomer; c) reacting the liquid phase with a base and isolating enantiomerically enriched (S)-4-[4-(dimethylamino)-1-(4′-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)benzonitrile enantiomer; d) combining enantiomerically enriched (S)-enantiomer obtained in c) with (+)-di-p-toluoyltartaric acid, in a solvent; and e) reacting a precipitate from d) with a base.
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Page/Page column 5
(2010/10/19)
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- Response to the comments by Elati et al. in response to our article examining one of their previous articles
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This reply highlights and discusses what we observe as internal inconsistencies in the data and analysis presented by Elati and coauthors in conjunction with their resolution protocols, as well as inconsistencies between their original manuscript, the ass
- Dancer, Robert James,Lopez De Diego, Heidi Lopez
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experimental part
p. 38 - 43
(2010/04/22)
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- Process for the preparation of escitalopram
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The present invention relates to a novel process for the preparation of Escitalopram, which comprises: (ii) de-methylating (±)-1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile (Formula II) (Citalopram) to produce (±)-1-[3-(methylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile (desmethyl Citalopram) (XII), (iii) isolating the pure desmethyl Citalopram (XII), (iv) separating the enantiomers from the pure desmethyl Citalopram (XII) with an optically active acid to obtain (S)-(+)-1-[3-(methylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile ((S)-(+)-desmethyl Citalopram) (XIII), (v) methylating an enantiomerically pure compound (XIII) using suitable methylating agent to produce Escitalopram (I).
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Page/Page column 10
(2009/02/10)
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- process for the preparation of escitalopram
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The present invention relates to an improved process for the preparation of Escitalopram of the Formula (I), which comprises, isolation of Diol compound as an oxalate salt, resolution of Diol compound and cyclization of resolved compound of Formula (VII). The present invention provides a process to obtain pure Diol compound by preparing its Oxalate salt, which is useful for resolution of enantiomers.
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Page/Page column 5
(2009/04/24)
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- Process for resolving citalopram via its (S)-enriched citalopram tartrate compound.
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The invention relates to an (S)-enriched citalopram tartrate compound, wherein at least 70% of the citalopram moieties are the (S)-enantiomer of citalopram.
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Page/Page column 6
(2008/12/08)
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- AN IMPROVED PROCESS FOR THE PREPARATION OF ESCITALOPRAM
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The present invention relates to an improved process for the preparation of Escitalopram of the Formula (I), which comprises, isolation of Diol compound as an oxalate salt, resolution of Diol compound and cyclization of resolved compound of Formula (VII). The present invention provides a process to obtain pure Diol compound by preparing its Oxalate salt, which is useful for resolution of enantiomers .
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Page/Page column 10-11
(2010/11/25)
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- CRYSTALLINE BASE OF ESCITALOPRAM AND ORODISPERSIBLE TABLETS COMPRISING ESCITALOPRAM BASE
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The present invention relates to the crystalline base of the well known antidepressant drug escitalopram, S-1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile, formulations of said base, a process for the preparation of purified salts of escitalopram, such as the oxalate, using the base, the salts obtained by said process and formulations containing such salts, and a process for the preparation of purified escitalopram free base or salts of escitalopram, such as the oxalate, using the hydrobromide, the salts obtained by said process and formulations containing such salts. Finally the present invention relates to an orodispersible tablet having a hardness of at least 22 N and an oral-disintegration time of less than 120 s and comprising an active pharmaceutical ingredient adsorbed onto a water soluble filler wherein the active pharmaceutical ingredient has a melting point in the range of 40-100° C., as well as a method for making such an orodispersible tablet.
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Page/Page column 7
(2008/06/13)
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- Chemoenzymatic process for the synthesis of escitalopram
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A process is described for the preparation of escitalopram and the pharmaceutically acceptable salts thereof starting from 5-cyanophthalide by a process which provides an enantioselective enzymatic deacylation reaction of a complex of the formula where R represents a C 1 -C 4 alkyl residue or an aryl residue under the action of an esterase from Aspergillus niger.
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- "PROCESS FOR PREPARATION OF CITALOPRAM AND ENANTIOMERS"
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The present invention provides a process for preparation of l-[3-(dimethylamino)propyl]- l-(4-fluorophenyl)-l,3-dihydro-5-isobenzofuran carbonitrile comprising reacting a compound of formula (Iva), in the presence of a base with a compound of formula RX, wherein R is selected from alkyl, alkenyl, aryl and heteroaryl which may be optionally substituted with electron withdrawing groups and X is selected from F, Cl, Br, I, CN, Otf and ORi, wherein Tf represents trifluoromethanesulfonyl group, and R1 is optionally substituted alkyl, Z is a cyano group or a group that may be converted to a cyano group; further wherein RX is selected such that an intermediate ether derivative, a compound of formula (Va) formed from said reaction cyclizes to a compound of formula (VI), and where Z is not a cyano group, conversion of the group Z in the compound of formula (VI) to a cyano group to form l-[3-(dimethylamino)ρropyl]-l-(4-fluoroρhenyl)-l,3-dihydro-5-isobenzofuran carbonitrile. The present invention also provides novel ether compound, a compound of formula (Va) and a process for preparation thereof.
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Page/Page column 20
(2010/10/20)
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- A PROCESS FOR THE PREPARATION OF ESCITALOPRAM
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The present invention relates to an improved process for the preparation of escitalopram of the formula-(I) which consists of a sequential double Grignard reaction on 5-iodophthalide to get the dihydroxy compound of formula-(XVI), its resolution using a chiral acid, cyclization of resolved compound of the formula-(XVII), and cyanation of compound of the formula-(XVIII) using DMF and copper (I) cyanide. The present process utilizes the facile displacement of iodo group with cyano group in the final step of escitalopram. Escitalopram is a widely used anti-depressant.
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Page/Page column 13-14
(2010/10/20)
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- PROCESS FOR THE PREPARATION OF CITALOPRAM AND ESCITALOPRAM
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A process is described for the preparation of citalopram (I) and of the active enantiomer thereof, escitalopram (II), which process comprises the cyclisation reaction of the corresponding precursor diol of the formula III or, respectively, IV in the presence of an azodicarboxylate, a phosphine and a strong base.
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Page/Page column 7
(2008/06/13)
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- CRYSTALLINE CITALOPRAM DIOL INTERMEDIATE ALKALI
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The present invention relates to the diol intermediate of citalopram useful for treatment of depression, that is to say, the crystal of free alkali of 3-hydroxylmethyl-4-[1-(4-fluorophenyl)-1-hydroxyl-4-(dimethylamino)] butylbenzonitrile and the method of crystallization thereof. The present invention has disclosed the method to prepare pure citalopram and its purified salts through crystallization of the described alkali;the optical resolution method of citalopram diol intermediate, the method to prepare S-citalopram and its purified salts by crystals mentioned above. The present invention has also disclosed the method to prepare citalopram and its purified salts, S-citalopram and its purified salts, as well as pharmaceutical formulation thereof obtained. Using methods of the present invention, the quality and yield of the product can be signally improved, and the production cost of the medicinal material can be decreased.
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Page/Page column 10
(2008/06/13)
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- METHOD FOR THE SEPARATION OF INTERMEDIATES WHICH MAY BE USED FOR THE PREPARATION OF ESCITALOPRAM
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The invention relates to a method of separating and isolating an acylated derivative of 4-[(S)-4-dimethylamino-1-(4-fluorophenyl)-1-hydroxybutyl]-3-hydroxymethylbenzonitrile by reaction of a mixture of the 4-[(S)-4-dimethylamino-1-(4-fluorophenyl)-1-hydroxy-butyl]-3-hydroxymethylbenzonitrile and an acylated derivative thereof with a compound which form a derivative of the 4-[(S)-4-dimethylamino-1-(4-fluorophenyl)-1-hydroxy-butyl]-3-hydroxymethylbenzonitrile containing a carboxylic acid group. The acylated derivative containing a carboxylic acid group precipitates once it is formed and may easily be separated from the reaction mixture.
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Page/Page column 27
(2008/06/13)
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- PREPARATION OF ESCITALOPRAM
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Enantiomerically enriched citalopram is prepared by methylating enantiomerically enriched didesmethylcitalopram, obtained by directly resolving racemic didesmethylcitalopram using a chiral acid.
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Page/Page column 29
(2008/06/13)
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- A PROCESS FOR THE PREPARATION OF HIGH PURITY ESCITALOPRAM
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The present invention discloses an improved process for the preparation of high purity escitalopram base of formula (I) by reacting the acid addition salt of formula (XVIII) with copper (I) cyanide and with or without copper (I) iodide in dimethylformamide medium at 145-150 °C. Cyanation on the acid addition salt of formula (XVIII) is found to be superior in yield and quality over the parent base compound of formula (XVII). The process is compatible to scale up operations thereby making the process commercially viable for escitalopram oxalate. Escitalopram oxalate is an antidepressant available in the market.
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Page/Page column 13
(2008/06/13)
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- PRODUCT
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A process of purifying citalopram, either in racemic or enantiomeric form, which process comprises (i) providing a crude mixture comprising citalopram, either in racemic or enantiomeric form, dissolved in a water immiscible organic solvent, and which mixture also includes one or more citalopram derivatives which are present as citalopram. impurities; (ii) washing the crude mixture with at least one dilute aqueous solution of a polybasic acid, either in free form or as a partial alkali metal salt, so as to separate citalopram from citalopram impurities present in the crude mixture; and (iii) where required converting citalopram free base, separated from citalopram impurities further to step (ii), to a pharmaceutically acceptable salt.
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- PROCESSES FOR THE PREPARATION OF ESCITALOPRAM AND ITS PRECURSOR
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The present invention relates to an improved process for the preparation of escitalopram of the formula-I which consists of a sequential double Grignard reaction on 5-bromophthalide, isolation of di-magnesium salt, neutralization of di-magnesium salt, resolution of dihydroxy compound of the formula-IV and cyclization of resolved compound of the formula-IV, cyanation of compound of the formula-IV using DMF and copper(I)cyanide. The present process utilizes the insoluble property of di-magnesium salt of formula-XII in a mixture of THF and a non-polar organic solvent and separates it from impurities by simple filtration thereby making the isolation and purification process simple.
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- METHOD FOR THE SEPARATION OF INTERMEDIATES WHICH MAY BE USED FOR THE PREPARATION OF ESCITALOPRAM
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The present invention relates to a novel method for the preparation of diol intermediates having the formula (II) and/or the opposite enantiomer of an acylated diol having the formula (IV) useful for the preparation of escitalopram involving selective enzymatic acylation or deacylation.
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- PROCESS AND INTERMEDIATES FOR PREPARING ESCITALOPRAM
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The antidepressant drug Escitalopram is prepared from 5-bromophthalide via the diol intermediate (4-bromo-2-(hydroxymethyl)phenyl)-(4-fluorophenyl)methanol. The racemic diol intermediate is converted to an enantiomerically enriched form by first converting the diol to a monoester intermediate and then reacting the monoester intermediate with an optically active acid, most preferably (+)-di-p-toluoyl tartaric acid, to form a salt. The salt is then crystallized to recover an enantiomerically enriched, crystalline form thereof. The monoester intermediate is preferably formed by reacting the racemic diol intermediate with an acid or a reactive acid derivative which, in a particularly preferred embodiment, is acetic anhydride.
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