- BIOCATALYTICAL PROCESS FOR RACEMIZATION OF D-EPHEDRINE
-
This invention relates to methods for racemization of dextro-rotatory ephedrine via enzymatic kinetic conversion, and is particularly useful for conversion of dextro- rotatory ephedrine (d- ephedrine) to racemic mixture of dextro-rotatory ephedrine (d-ephedrine) and levo-rotatory ephedrine (l-ephedrine) to recover the levo-rotatory ephedrine that exhibit potential bronchodilatory and anti-hypotensive activities. The process provides a suspension of Rhizopus Oryzae fungi pellets in diammonium phosphate buffer having pH in the range of pH 5 to 9 and effective sonication to extract specific enzymes for inversion of functional groups present on the chiral carbon atom of d-ephedrine molecule at low temperature which has advantages of working at lower temperature range (20 to 50 °C), lower energy consumption, lesser formation of by-products.
- -
-
Page/Page column 9-12
(2020/05/28)
-
- Process for preparing beta-aminoalcohol from terminal olefin
-
The invention provides a method for preparing beta-aminoalcohol from terminal olefin. The method comprises the following steps: with the terminal olefin as a raw material, adding dibromohydantoin, conducting stirring, and then adding organic amine to obtain corresponding beta-aminoalcohol. The method has the advantages of mild conditions, easy operation, cheap raw materials, and wide application prospect.
- -
-
Paragraph 0031; 0032; 0048
(2020/06/17)
-
- Peroxygenase-Catalysed Epoxidation of Styrene Derivatives in Neat Reaction Media
-
Biocatalytic oxyfunctionalisation reactions are traditionally conducted in aqueous media limiting their production yield. Here we report the application of a peroxygenase in neat reaction conditions reaching product concentrations of up to 360 mM.
- Alcalde, Miguel,Arends, Isabel W. C. E.,Hollmann, Frank,Paul, Caroline E.,Rauch, Marine C. R.,Tieves, Florian
-
-
- Evaluation of the Edman degradation product of vancomycin bonded to core-shell particles as a new HPLC chiral stationary phase
-
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.
-
p. 1067 - 1078
(2018/08/01)
-
- Chiral Manganese Aminopyridine Complexes: the Versatile Catalysts of Chemo- and Stereoselective Oxidations with H2O2
-
In the last decade, manganese(II) complexes with N-donor tetradentate aminopyridine ligands emerged as efficient catalysts of enantioselective epoxidation of olefins and direct selective oxidation of C?H groups in complex organic molecules, with environmentally benign oxidant hydrogen peroxide. In this personal account, we summarize the progress of these catalysts with regard to ligands design, structure-reactivity correlations, evaluation of the substrate scope, as well as mechanistic studies, shedding light on the nature of active sites and the mechanisms of selective oxygenations. Several practically promising catalytic syntheses with the aid of Mn aminopyridine catalysts are exemplified.
- Ottenbacher, Roman V.,Talsi, Evgenii P.,Bryliakov, Konstantin P.
-
-
- Unlocking the potential of phenacyl protecting groups: CO2-based formation and photocatalytic release of caged amines
-
Orthogonal protection and deprotection of amines remain important tools in synthetic design as well as in chemical biology and material research applications. A robust, highly efficient, and sustainable method for the formation of phenacyl-based carbamate esters was developed using CO2 for the in situ preparation of the intermediate carbamates. Our mild and broadly applicable protocol allows for the formation of phenacyl urethanes of anilines, primary amines, including amino acids, and secondary amines in high to excellent yields. Moreover, we demonstrate the utility by a mild and convenient photocatalytic deprotection protocol using visible light. A key feature of the [Ru(bpy)3](PF6)2-catalyzed method is the use of ascorbic acid as reductive quencher in a neutral, buffered, two-phase acetonitrile/water mixture, granting fast and highly selective deprotection for all presented examples.
- Speckmeier, Elisabeth,Klimkait, Michael,Zeitler, Kirsten
-
p. 3738 - 3745
(2018/04/14)
-
- Peptide Metal-Organic Frameworks for Enantioselective Separation of Chiral Drugs
-
We report the use of a chiral Cu(II) 3D metal-organic framework (MOF) based on the tripeptide Gly-l-His-Gly (GHG) for the enantioselective separation of metamphetamine and ephedrine. Monte Carlo simulations suggest that chiral recognition is linked to preferential binding of one of the enantiomers as a result of either stronger or additional H-bonds with the framework that lead to energetically more stable diastereomeric adducts. Solid-phase extraction of a racemic mixture by using Cu(GHG) as the extractive phase permits isolating >50% of the (+)-ephedrine enantiomer as target compound in only 4 min. To our knowledge, this represents the first example of a MOF capable of separating chiral polar drugs.
- Navarro-Sánchez, José,Argente-García, Ana I.,Moliner-Martínez, Yolanda,Roca-Sanjuán, Daniel,Antypov, Dmytro,Campíns-Falcó, Pilar,Rosseinsky, Matthew J.,Martí-Gastaldo, Carlos
-
p. 4294 - 4297
(2017/04/03)
-
- Diastereoselective hydrogenation of α,β-unsaturated but-2-enamides to access the chiral 3-(p-tolyl) butanoic acids
-
An alternative methodology for the synthesis of chiral 3-(p-tolyl) butanoic acids is presented. This was accomplished through the diastereoselective hydrogenation reaction of different chiral N-3-(p-tolyl) but-2-enamides, using Pd/C in EtOH, to produce the corresponding chiral N-3-(p-tolyl) butanamides with high chemical yields and moderate diastereomeric ratios. Removal of the chiral auxiliary from N-3-(p-tolyl) butanamides gave the respective enantiomerically pure acids.
- Jiménez, Jacqueline,López, Mildred,Carranza, Vladimir,Mendoza, Angel,Varela, Jenaro,Sansinenea, Estibaliz,Ortiz, Aurelio
-
p. 235 - 239
(2016/12/28)
-
- POLYMORPHIC AND AMORPHOUS FORMS OF (R)-2-HYDROXY-2-METHYL-4-(2,4,5-TRIMETHYL-3,6-DIOXOCYCLOHEXA-1,4-DIENYL)BUTANAMIDE
-
Disclosed herein are polymorphic and amorphous forms of anhydrate, hydrate, and solvates of (R)-2-hydroxy-2-methyl-4-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dienyl)butanamide and methods of using such compositions for treating or suppressing oxidative stress disorders, including mitochondrial disorders, impaired energy processing disorders, neurodegenerative diseases and diseases of aging. Further disclosed are methods of making such polymorphic and amorphous forms.
- -
-
Paragraph 0188
(2016/07/05)
-
- A short enantioselective synthesis of ephedrine, amphetamine and their analogues via two stereocentered Co(III)-catalyzed hydrolytic kinetic resolution of racemic syn-benzyloxy epoxide
-
An efficient route for the synthesis of 6 drugs belonging to phenethylamine and amphetamine classes in excellent overall yields and high optical purity has been described. The strategy involves introduction of stereogenic centers by means of two-stereocentered Co(III)-catalyzed hydrolytic kinetic resolution (HKR) of racemic syn-benzyloxy epoxide followed by Pd-catalyzed regioselective cationic hydrogenation of amino alcohols as the key reactions.
- Lalwani, Komal G.,Sudalai, Arumugam
-
supporting information
p. 6488 - 6490
(2015/11/16)
-
- Measurement of stable isotope ratios in methylamphetamine: A link to its precursor source
-
The illicit drug methylamphetamine is often prepared from the precursor ephedrine or pseudoephedrine, which in turn are obtained by three processes: extraction from the Ephedra plant ("natural"), via fermentation of sugars ("semi-synthetic"), and by a "fully synthetic" route from propiophenone. We report the first method to differentiate between the three industrial routes used to produce the precursors ephedrine and pseudoephedrine by measurement of stable isotope ratios of nitrogen (δ15N), hydrogen (δ2H), and carbon (δ13C). Analysis of 782 samples of seized methylamphetamine allowed classification into three groups using k-means clustering or the expectation-maximization algorithm applied to a Gaussian mixture model. By preparation of 30 samples of ephedrine by the "fully synthetic" industrial process and measuring their δ15N, δ2H, and δ13C values, we observed that 15N becomes significantly depleted compared to the methylamine starting material. Conversion of ten ephedrine samples to methylamphetamine showed that this depletion is maintained in the final drug product, of which the δ15N, δ13C, and δ2H values were distinct from those of ephedrine and methylamphetamine samples of a semi-synthetic (fermentation pathway) origin. Combining modeling analysis with the new experiments and published information on the values of δ2H gave a definitive assignment of the three model groups, and equations to obtain probabilities for the precursor origin of any new sample. A simple rule of thumb is also presented. Making an assignment using delta values is particularly useful when no other chemical profiling information is available.
- Salouros, Helen,Sutton, Gordon J.,Howes, Joanna,Hibbert, D. Brynn,Collins, Michael
-
p. 9400 - 9408
(2013/10/21)
-
- Synthesis of three novel fluorine-18 labeled analogues of l -deprenyl for Positron Emission Tomography (PET) studies of Monoamine Oxidase B (MAO-B)
-
The aim in this project was to synthesize and to study fluorine-18 labeled analogues of l-deprenyl which bind selectively to the enzyme monoamine oxidase B (MAO-B). Three fluorinated l-deprenyl analogues have been generated in multistep organic syntheses. The most promising fluorine-18 compound N-[(2S)-1-[18F]fluoro-3-phenylpropan-2-yl]-N-methylprop-2-yn-1-amine (4c) was synthesized by a one-step fluorine-18 nucleophilic substitution reaction. Autoradiography on human brain tissue sections demonstrated specific binding for compound 4c to brain regions known to have a high content of MAO-B. In addition, the corresponding nonradioactive fluorine-19 compound (13) inhibited recombinant human MAO-B with an IC50 of 170.5 ±29 nM but did not inhibit recombinant human MAO-A (IC50 > 2000 nM), demonstrating its specificity. Biodistribution of 4c in mice showed high initial brain uptake leveling at 5.2 ±0.04%ID/g after 2 min post injection. In conclusion, compound 4c is a specific inhibitor of MAO-B with high initial brain uptake in mice and is, therefore, a candidate for further investigation in PET.
- Nag, Sangram,Lehmann, Lutz,Heinrich, Tobias,Thiele, Andrea,Kettschau, Georg,Nakao, Ryuji,Gulyás, Balázs,Halldin, Christer
-
supporting information; experimental part
p. 7023 - 7029
(2011/12/15)
-
- PROCESSES AND INTERMEDIATES FOR PREPARING A MACROCYCLIC PROTEASE INHIBITOR OF HCV
-
A process for preparing [(1R,2R)-4-oxo-1,2-cyclopentanedicarboxylic acid II, by the resolution of racemic 4-oxo-1,2-cyclopentanedicarboxylic acid (V), said process comprising: (a) reacting 4-oxo-1,2-cyclopentanedicarboxylic acid (V) with brucine or (1R,2S)-(-)- ephedrine, thus preparing the bis-brucine or bis-(1R,2S)-(-)-ephedrine salt of (V), and (b) precipitating selectively the bis-brucine or bis-(1R,2S)-(-)-ephedrine salt of (1R,2R)-4-oxo-1,2-cyclopentanedicarboxylic acid II, while the bis-brucine or bis- (1R,2S)-(-)-ephedrine salt of [(1S,2S)-4-oxo-1,2-cyclopentanedicarboxylic acid stays in solution; (c) liberating the acid II by removal of brucine or (1R,2S)-(-)-ephedrine from the precipitated salt obtained in step (b).
- -
-
Page/Page column 21-22
(2011/10/10)
-
- Synthesis of 2-Arylethylamines by the Curtius Rearrangement
-
2-Arylethylamine derivatives were synthesized using the Curtius reaction and with three different methods of preparing the acyl azide functional group. Carbamates derived from isocyanate were convenient protecting groups for alkylation of amines. Starting from benzaldehyde, amphetamine was prepared in three steps through an oxazolidin-2-one intermediate in 62% overall yield. Copyright Taylor & Francis Group, LLC.
- Schulze, Matthias
-
experimental part
p. 1461 - 1476
(2010/07/08)
-
- Composition and stereochemistry of ephedrine alkaloids accumulation in Ephedra sinica Stapf
-
Ephedra sinica Stapf (Ephedraceae) is a widely used Chinese medicinal plant (Chinese name: Ma Huang). The main active constituents of E. sinica are the unique and taxonomically restricted adrenergic agonists phenylpropylamino alkaloids, also known as ephedrine alkaloids: (1R,2S)-norephedrine (1S,2S)-norpseudoephedrine, (1R,2S)-ephedrine, (1S,2S)-pseudoephedrine, (1R,2S)-N-methylephedrine and (1S,2S)-N-methylpseudoephedrine. GC-MS analysis of freshly picked young E. sinica stems enabled the detection of 1-phenylpropane-1,2-dione and (S)-cathinone, the first two putative committed biosynthetic precursors to the ephedrine alkaloids. These metabolites are only present in young E. sinica stems and not in mature stems or roots. The related Ephedra foemina and Ephedra foliata also lack ephedrine alkaloids and their metabolic precursors in their aerial parts. A marked diversity in the ephedrine alkaloids content and stereochemical composition in 16 different E. sinica accessions growing under the same environmental conditions was revealed, indicating genetic control of these traits. The accessions can be classified into two groups according to the stereochemistry of the products accumulated: a group that displayed only 1R stereoisomers, and a group that displayed both 1S and 1R stereoisomers. (S)-cathinone reductase activities were detected in E. sinica stems capable of reducing (S)-cathinone to (1R,2S)-norephedrine and (1S,2S)-norpseudoephedrine in the presence of NADH. The proportion of the diastereoisomers formed varied according to the accession tested. A (1R,2S)-norephedrine N-methyltransferase capable of converting (1R,2S)-norephedrine to (1R,2S)-ephedrine in the presence of S-adenosylmethionine (SAM) was also detected in E. sinica stems. Our studies further support the notion that 1-phenylpropane-1,2-dione and (S)-cathinone are biosynthetic precursors of the ephedrine alkaloids in E. sinica stems and that the activity of (S)-cathinone reductases directs and determines the stereochemical branching of the pathway. Further methylations are likely due to N-methyltransferase activities.
- Krizevski, Raz,Bar, Einat,Shalit, Or,Sitrit, Yaron,Ben-Shabat, Shimon,Lewinsohn, Efraim
-
experimental part
p. 895 - 903
(2010/08/19)
-
- Polymer-immobilized catalyst for asymmetric hydrogenation of racemic α-(N-benzoyl-N-methylamino)propiophenone
-
Asymmetric hydrogenation of α-(N-benzoyl-N-methylami-no)propiophenone through dynamic kinetic resolution was performed by using a polymer-immobilized chiral diamine-ruthenium-BINAP-t-BuOK system in order to yield syn-β-amidealcoholexclusivelywithnearlyperfectenantioselectivity.
- Chiwara, Vinia Ipai,Haraguchi, Naoki,Itsuno, Shinichi
-
body text
p. 1391 - 1393
(2009/07/04)
-
- Stereocontrolled alkylative construction of quaternary carbon centers
-
Protocols for the stereodefined formation of α,α-disubstituted enolates of pseudoephedrine amides are presented followed by the implementation of these in diastereoselective alkylation reactions. Direct alkylation of α,α-disubstituted pseudoephedrine amide substrates is demonstrated to be both efficient and diastereoselective across a range of substrates, as exemplified by alkylation of the diastereomeric pseudoephedrine α-methylbutyramides, where both substrates are found to undergo stereospecific replacement of the α-C-H bond with α-C-alkyl, with retention of stereochemistry. This is shown to arise by sequential stereospecific enolization and alkylation reactions, with the alkyl halide attacking a common π-face of the E- and Z-enolates, proposed to be opposite the pseudoephedrine alkoxide side chain. Pseudoephedrine α-phenylbutyramides are found to undergo highly stereoselective but not stereospecific α-alkylation reactions, which evidence suggests is due to facile enolate isomerization. Also, we show that α,α-disubstituted pseudoephedrine amide enolates can be generated in a highly stereocontrolled fashion by conjugate addition of an alkyllithium reagent to the s-cis-conformer of an α-alkyl-α,β-unsaturated pseudoephedrine amide, providing α,α-disubstituted enolate substrates that undergo alkylation in the same sense as those formed by direct deprotonation. Methods are presented to transform the α-quaternary pseudoephedrine amide products into optically active carboxylic acids, ketones, primary alcohols, and aldehydes. Copyright
- Kummer, David A.,Chain, William J.,Morales, Marvin R.,Quiroga, Olga,Myers, Andrew G.
-
supporting information; experimental part
p. 13231 - 13233
(2009/02/06)
-
- The preparation of stable aziridinium ions and their ring-openings
-
The reaction of enantiomerically pure 2-substituted 1-phenylethyl-aziridine with methyl trifluoromethanesulfonate generated a stable methylaziridinium ion, which was reacted with various external nucleophiles, including nitrile, to yield synthetically valuable and optically pure acyclic amine derivatives in a completely regio- and stereoselective manner. The Royal Society of Chemistry.
- Kim, Yongeun,Ha, Hyun-Joon,Yun, Sae Young,Lee, Won Koo
-
supporting information; experimental part
p. 4363 - 4365
(2009/03/12)
-
- Asymmetric hydrogenation of aromatic ketones catalyzed by the TolBINAP/DMAPEN-ruthenium(II) complex: A significant effect of N-substituents of chiral 1,2-diamine ligands on enantioselectivity
-
(Chemical Equation Presented) Asymmetric hydrogenation of acetophenone in the presence of Ru(II) catalysts coordinated by TolBINAP and a series of chiral 1,2-diamines was studied. The sense and degree of enantioselectivity were highly dependent on the N-substituents of the diamine ligands. The N-substituent effect was discussed in detail. Among these catalysts, the (S)-TolBINAP/(R)- DMAPEN-Ru(II) complex showed the highest enantioselectivity. The mode of enantioface selection was interpreted by using transition state models based on the X-ray structure of the catalyst precursor. The chiral catalyst effected the hydrogenation of alkyl aryl ketones and arylglyoxal dialkyl acetals to afford the chiral alcohol in >99% ee in the best cases. Hydrogenation of racemic benzoin methyl ether with the chiral catalyst through dynamic kinetic resolution gave the anti-alcohol (syn:anti = 3:97) in 98% ee, while the reaction of α-amidopropiophenones resulted in the syn-alcohols (symanti = 96:4 to >99:1) in >98% ee.
- Ooka, Hirohito,Arai, Noriyoshi,Azuma, Keita,Kurono, Nobuhito,Ohkuma, Takeshi
-
supporting information; experimental part
p. 9084 - 9093
(2009/04/11)
-
- General asymmetric hydrogenation of α-branched aromatic ketones catalyzed by TolBINAP/DMAPEN-ruthenium(II) complex
-
(Chemical Equation Presented) A catalyst system consisting of RuCl 2[(S)-tolbinap][(R)-dmapen] and t-C4H9OK in 2-propanol effects asymmetric hydrogenation of arylglyoxal dialkylacetals to give the α-hydroxy acetals in up to 98% ee. Hydrogenation of racemic α-amidopropiophenones under dynamic kinetic resolution predominantly gives the syn alcohols in up to 99% ee and >98% de, while the reaction of racemic bezoin methyl ether gives the anti alcohols in excellent stereoselectivity.
- Arai, Noriyoshi,Ooka, Hirohito,Azuma, Keita,Yabuuchi, Toshio,Kurono, Nobuhito,Inoue, Tsutomu,Ohkuma, Takeshi
-
p. 939 - 941
(2007/10/03)
-
- Convenient access to glutamic acid side chain homologues compatible with solid phase peptide synthesis
-
(Chemical Equation Presented) Preparation of several side chain length variants of glutamic acid is achieved via olefin cross metathesis of allyl glycine derivatives. The products are suitably protected for direct use in Fmoc solid-phase peptide synthesis, as demonstrated by successful synthesis of test sequences.
- Ryan, Shannon J.,Zhang, Yongda,Kennan, Alan J.
-
p. 4765 - 4767
(2007/10/03)
-
- Nonracemic α-allenyl carbinols from asymmetric propargylation with the 10-trimethylsilyl-9-borabicyclo[3.3.2]decanes
-
(Chemical Equation Presented) The asymmetric propargylboration of aldehydes at -78°C in 98% ee). The reagents 1 are easily prepared in both enantiomeric forms with a simple Grignard procedure and air-stable borinate complexes 2. The ozonolysis of 6 proceeds smoothly through an acylsilane intermediate to give a TMS ester, which is hydrolyzed to the α-hydroxy acid quantitatively with water.
- Hernandez, Eliud,Soderquist, John A.
-
p. 5397 - 5400
(2007/10/03)
-
- Novel lincomycin derivatives possessing antibacterial activity
-
Novel lincomycin derivatives are disclosed. These lincomycin derivatives exhibit antibacterial activity. The compounds of the subject invention may exhibit potent activities against bacteria, including Gram positive organisms, and may be useful antimicrobial agents. Methods of synthesis and of use of the compounds are also disclosed.
- -
-
-
- Diastereoselective reduction of α-aminoketones: Synthesis of anti- and syn-β-aminoalcohols
-
Reduction of N-t-BOC-protected-N-alkyl α-aminoketones with LiEt 3BH or Li(S-Bu)3BH furnishes protected syn-β-aminoalcohols with high selectivities. In contrast, removal of the BOC group followed by reduction of the aminoketone gives anti-β- aminoalcohols with variable selectivities. With aromatic ketones, selectivities are typically high while aliphatic ketones show mediocre to high selectivities depending on steric considerations.
- Fraser, David S.,Park, Sheldon B.,Chong, J. Michael
-
-
- Determination of origin of ephedrine used as precursor for illicit methamphetamine by carbon and nitrogen stable isotope ratio analysis
-
The sale of ephedrine, one of the precursors of methamphetamine, is strictly controlled and monitored in various countries to prevent the production of illicit methamphetamine. There are three kinds of production scheme for ephedrine manufacture, and it is very useful for precursor control to investigate the origin of ephedrine used for the synthesis of illicit methamphetamine. By means of stable isotope ratio mass spectrometry (IR-MS), we investigated the origin of ephedrine based on the δ13C and δ15N values. The various origins of ephedrine (biosynthetic, semisynthetic, or synthetic) could be discriminated clearly by using these values. The δ15N values of synthetic ephedrine were more negative than those of ephedrine from other sources. By the repeated distillation of methylamine in our laboratory, we confirmed that this could be due to isotope separation during distillation for the purification of methylamine used for ephedrine synthesis. The values for ephedrine used as the precursor were well-correlated with those for methamphetamine synthesized from it. This drug characterization analysis should be useful to illuminate the origin of the precursors used for clandestine methamphetamine and to trace the diversion of medicinal ephedrine for illicit manufacture of methamphetamine.
- Kurashima, Naoki,Makino, Yukiko,Sekita, Setsuko,Urano, Yasuteru,Nagano, Tetsuo
-
p. 4233 - 4236
(2007/10/03)
-
- Stereoisomers with high affinity for adrenergic receptors
-
The present invention provides stereoscopically-pure diastereomers of Formula I: 1In a preferred embodiment, the stereoisomers of the present invention are of Formula II, depicted below: 2R2, R3 and le are independently H, OH, OCH3, CH2OH, NHCONH2, NH2, halogen or CF3, and R1 is pyridine, or an amine which may be substituted with hydrogen, lower alkyl, lower alkylenearyl, lower alkylenephenyl, lower alkylenehydroxyphenyl, lower alkyleneamine, lower alkyleneaminoaryl, lower alkylaminohydroxyphenyl, or a similar functional group. TV is hydrogen, hydroxyl or methyl; R6 is hydrogen, lower alkyl, lower alkylenaryl, lower alkylenephenyl, lower alkylenehydroxyphenyl, lower alkyleneamine, lower alkyleneaminoaryl, lower alkylaminohydroxyphenyl, and the like. For both Formula I and Formual II, the firs carbon on the side chain progressing from the ring is preferably in the R-configuration. The second carbon atom on the side chain of Formula II, which is attached to IV, may or may not be a chiral center. However, when the second carbon atom is a chiral center, it is preferably in the S-configuration. The present invention contemplates each stereoisomer of Formula I and II in substantially-pure form. The present invention also provides methods of relieving nasal, sinus and bronchial congestion and of treating attention deficit hyperactivity disorder and obesity. The present stereoisomers may also be used to induce pupil dilation. These methods include administering to a mammal a composition containing a therapeutically effective amount of a stereoscopically-pure stereoisomer of Formula I or II with a pharmaceutically acceptable excipient.
- -
-
-
- Asymmetric synthesis of (-)-pseudoephedrine from (2S,3S)-3-phenyloxiran-2-ylmethanol. Stereospecific interchange of amino and alcohol functions
-
A ring-opening reaction of N-methylaziridines with Boc2O/NaI has been applied to the asymmetric synthesis of pseudoephedrine. 3-Methylamino-3-phenyl-1,2-propanediol 1, derived from (2S,3S)-3-phenyloxiran-2-ylmethanol, was converted into the oxazolidin-2-one 4, a precursor of pseudoephedrine. The reaction occurs with a stereospecific interchange of amino and alcohol functions.
- Testa, Ma Luisa,Hajji, Chakib,Zaballos-Garcia, Elena,Belen Garcia-Segovia, Ana,Sepulveda-Arques, Jose
-
p. 1369 - 1372
(2007/10/03)
-
- The imine (+)-pseudoephedrine glycinamide: A useful reagent for the asymmetric synthesis of (R)-α-amino acids
-
The new imine derived from Myers (+)-pseudoephedrine glycinamide can be diastereoselectively alkylated with alkyl halides at room temperature using NaOEt or LiO-tert-Bu as bases under phase transfer conditions. Hydrolysis to the corresponding alkylated products was easily achieved under mild conditions to afford (R)-α-amino acids.
- Guillena, Gabriela,Najera, Carmen
-
p. 181 - 183
(2007/10/03)
-
- Enantiomeric analysis of pharmaceutical compounds by Ion/molecule reactions
-
Protonated complexes involving cyclodextrin hosts and guest compounds that are pharmacologically important are produced in the gas phase and reacted with a gaseous amine. The guest is exchanged to produce a new protonated complex with the amine. The reaction is enantioselective and is used to develop a method for determining enantiomeric excess using only mass spectrometry. The pharmaceutical compounds include DOPA, amphetamine, ephedrine, and penicillamine. The presence of more than one reacting species is observed with DOPA and penicillamine. Molecular dynamics calculations are used to understand the nature of the interactions and the possible source of the variations in the reactivities.
- Grigorean,Lebrilla
-
p. 1684 - 1691
(2007/10/03)
-
- 2-AMINO-4-PHENYL-4-OXO-BUTYRIC ACID DERIVATIVES
-
Use in the prevention and/or in the treatment of neurodegenerative diseases of 2-amino-4-phenyl-4-oxo-butyric acid derivatives which act as kynureninase enzyme inhibitors and/or kynurenine-3-hydroxylase enzyme inhibitors. Several of these derivatives are new and, as such, constitute a further object of this invention, together with the process for their preparation and the pharmaceutical compositions containing them.
- -
-
-
- Process for the separation of a mixture of enantiomers
-
A diastereomer complex obtained via a process for the separation of enantiomers is disclosed, wherein separation can be rapidly effected such that enantiomers are obtained with high e.e. values. The process pets the separation of mixtures of enantiomers in which more than one resolving agent is used, of which at least one resolving agent is optically active, and which yields a diastereomer complex containing at least two resolving agents in optically active form. The process provides for, inter alia, a diastereomer complex having at least three compounds of which at least two compounds are resolving agents in optically active form, and at least one compound is an onantiomer in optically active form. Also provided is a diastereomer complex having at least three compounds of which at lea one compound is a resolving agent in optically active form, and at least two compounds which are enantiomers in optically active form.
- -
-
-
- Process for producing optically active chrysanthemic acid
-
The present invention provides an advantageous method for producing an optically active chrysanthemic acid. Disclosed is a method for producing an optically active chrysanthemic acid whose trans isomer ratio and optical purity are improved, which comprises reacting chrysanthemic acid having a trans isomer ratio of not less than 50% and an optical purity of not less than 10% e.e. with an optically active organic amine to optically resolve said chrysanthemic acid.
- -
-
-
- Asymmetric aldol reactions using (S,S)-(+)-pseudoephedrine-based amides: Stereoselective synthesis of α-methyl-β-hydroxy acids, esters, ketones, and 1,3-syn and 1,3-anti diols
-
A very efficient method for performing stereoselective aldol reactions is reported. The reaction of (S,S)-(+)-pseudoephedrine-derived propionamide enolates with several aldehydes yielded exclusively one of the four possible diastereomers in good yields, although transmetalation of the firstly generated lithium enolate with a zirconium(II) salt, prior to the addition of the aldehyde, is necessary in order to achieve high syn selectivity. The so-formed syn-α-methyl-β-hydroxy amides were transformed into other valuable chiral nonracemic synthons such as α-methyl-β-hydroxyacids, esters, and ketones. Finally, a stereocontrolled reduction procedure starting from the so-obtained α-methyl-β-hydroxy ketones has been developed allowing the synthesis of either 1,3-syn- or 1,3-anti-α-methyl-1,3-diols in almost enantiopure form by choosing the appropriate reaction conditions.
- Vicario, Jose L.,Badia, Dolores,Dominguez, Esther,Rodriguez, Monica,Carrillo, Luisa
-
p. 3754 - 3759
(2007/10/03)
-
- Photocycloaddition of N-acyl enamines to aldehydes and its application to the synthesis of diastereomerically pure 1,2-amino alcohols
-
The regio- and stereoselective synthesis of the protected cis-3- aminooxetanes cis-5 and cis-7 is reported. The oxetanes were obtained by the photocycloaddition of aliphatic (6c-e) and aromatic (4, 6a) aldehydes to the corresponding enamides (1a-d,h) or enecarbamates (1e-g). The enamine derivatives used in the Paterno-Buchi reaction were either commercially available or prepared from the corresponding acetaldehyde imines 2 by acylation. The oxetane formation proceeded with good-to-excellent simple diastereoselectivity for aromatic aldehydes (56-82% yield) and moderate selectivity for aliphatic aldehydes (46-55% yield). The cis-3-aminooxetanes are precursors for syn- and anti-1,2-amino alcohols. The relative configuration established in the photochemical step was retained upon nucleophilic ring opening between the oxygen atom and carbon atom C-4. By this means, syn-1,2-amino alcohols such as 8 and 10 were available in good yields. In contrast, the N-Boc-protected cis-3-aminooxetanes cis-5e and cis- 5f were transformed into anti-1,2-amino alcohols. Upon treatment with trifluoroacetic acid, they underwent an intramolecular nucleophilic substitution at the carbon atom C-2 of the oxetane and the oxazolidinones 11 and 12 were formed. Because the substitution occurs with inversion of configuration, anti-1,2-amino alcohols, e.g., ephedrine (15), are accessible.
- Bach,Schroder
-
p. 1265 - 1273
(2007/10/03)
-
- Method for producing optically active chrysanthemic acid
-
The present invention provides an advantageous method for producing an optically active chrysanthemic acid. Disclosed is a method for producing an optically active chrysanthemic acid whose trans isomer ratio and optical purity are improved, which comprises reacting chrysanthemic acid having a trans isomer ratio of not less than 50% and an optical purity of not less than 10% e.e. with an optically active organic amine to optically resolve said chrysanthemic acid.
- -
-
-
- Fluoxetine process from benzoylpropionic acid
-
A synthesis of fluoxetine is disclosed. The process begins with a lower alkyl ester of 3-benzoylpropionic acid, which is reduced in the presence of a chiral ligand to produce the corresponding γ-hydroxy ester, and the ester is cleaved. The free acid is then condensed with the alcohol to form a γ-lactone, which is treated with ammonia to provide the γ-hydroxy amide. The amide undergoes a Hoffman rearrangement to provide a 2-oxo-1,3 oxazine, which is reduced to 3-(methylamino)-1-phenyl-1-propanol. The alcohol is deprotonated and reacted with a 4-chloro- or 4-fluoro benzotrifluoride to provide fluoxetine free base.
- -
-
-
- Scavenger assisted combinatorial process for preparing libraries of amides, carbamates and sulfonamides
-
This invention relates to a novel solution phase process for the preparation of amide, carbamate, and sulfonamide combinatorial libraries. These libraries have utility for drug discovery and are used to form wellplate components of novel assay kits.
- -
-
-
- Stereoselective synthesis of (1R)- and (1R,2S)-1-aryl-2-alkylamino alcohols from (R)-cyanohydrins
-
Hydrogenation of (R)-cyanohydrins (R)-1 with LiAlH4 occurs without racemization to give the (R)-2-amino alcohols (R)-3. (1R,2S)-2-Amino alcohols (1R,2S)-4 are obtained with high diastereoselectivity by addition of methyl Grignard to O-silyl protected cyanohydrins (R)-2 and subsequent hydrogenation with NaBH4. The N-alkylated 2-amino alcohols (R)-8 and (1R,2S)-9 can be prepared either by reductive alkylation of the corresponding 2-amino alcohols (R)-3 and (1R,2S)-4, respectively, or by a transimination reaction of the Grignard addition products with primary amines and subsequent hydrogenation with NaBH4. The lower diastereoselectivity of hydrogenation in case of the N-alkylmino compounds in comparison to the N-unsubstituted imines is explained by a weaker chelating effect.
- Effenberger, Franz,Gutterer, Beate,Jaeger, Juergen
-
p. 459 - 467
(2007/10/03)
-
- Stereoselective umpolung reactions with metalated p-chiral cyanohydrin phosphates-enantioselective synthesis of tertiary cyanohydrins
-
We present the first cyanohydrin derivative 4 that allows diastereoselective umpolung reactions. In 4 the OH group of the cyanohydrin is linked with a chiral phosphate, which can be removed hydrolytically after asymmetric synthesis. Cyclization of pseudoephedrine 1d with POCl3 gave 2d. This was followed by addition of racemic benzaldehyde cyanohydrin 3 to give the key intermediate 4d. With complete retention of the configuration at phosphorus. Deprotonation of 4d, followed by addition of a wide variety of electrophiles afforded the crystalline products 5 with high diastereomeric excesses (de up to 94%). High asymmetric induction was also achieved for the reaction of 4-Li+ with acyl halides, α-bromoacetates, 2-cycloalkenones, α,β-unsaturated esters, and γ-bromoacetates. Lewis acid assisted hydrolysis proceeded without racemization and gave high yields of ketone cyanohydrins 6. From the ring-opened chiral auxiliary 7, optically pure pseudoephedrine 1 was readily recovered by acid hydrolysis. Optically pure (R) and (S) ketone cyanohydrins are now accessible in a very general strategy, which circumvents the substrate limitations of enzymatic synthesis.
- Schrader, Thomas
-
p. 1273 - 1282
(2007/10/03)
-
- Synthesis of syn- and anti-1,2-amino alcohols by regioselective ring opening reactions of cis-3-aminooxetanes
-
N-t-Butyloxycarbonyl (Boc) substituted cis-2-phenyl-3-aminooxetanes 3 undergo a ring expansion to oxazolidinones 5 upon treatment with trifluoroacetic acid. The reaction occurs at the C(2) position under inversion of configuration. Alternatively, 3-aminooxetanes can be ring-opened at the less substituted C(4) position with retention of the relative configuration between C(2) and C(3) as exemplified by the synthesis of (+)-pseudoephedrine (2). The cis3-aminooxetanes serve as precursors for either syn- or anti-1,2-amino alcohols.
- Bach, Thorsten,Schroeder, Juergen
-
p. 3707 - 3710
(2007/10/03)
-
- Amino acid derivatives, the process for their preparation and their applications to therapy
-
Amino acid derivatives of formula (Ia) and (Ib) and prodrugs thereof containing a group responsible for chelating the zinc atom of enkephalinase and angiotensin convertase enzymes are disclosed as inhibitors of these enzymes.
- -
-
-
- Chiral separation of drug enantiomers by capillary electrophoresis using succinyl-β-cyclodextrin
-
A capillary electrophoretic method for the enantiomeric separation of 11 drugs was developed using an uncoated fused-silica capillary and succinyl β-cyclodextrin as a chiral additive. The effect of the pH of the background electrolyte on selectivity and resolution was studied in the range pH 3.3-9.3. Best results were obtained in a neutral medium. Generally, the presence of a hydroxy group at the chiral C-atom of the analyte seems to be essential because similar compounds without a hydroxy group at the chiral centre did not show chiral resolution. In addition to the enantioselective inclusion into the chiral cavity, hydrogen bondings and formation of ion pairs between the negatively charged selector and cationic analytes can be assumed as mechanisms.
- Schmid,Wirnsberger,Guebitz
-
p. 852 - 854
(2007/10/03)
-
- (1S,2S)-2-Amino-1-phenyl-1,3-propanediol, a spin off from chloramphenicol manufacture, as chiral synthon for (1S, 2S)-pseudoephedrine and (R)-phenylalaninol
-
(1S,2S)-2-Amino-1-phenyl-1,3-propanediol (3a), a discarded optically active material in one of the processes for the manufacture of chloramphenicol, has been transformed into (S,S)-pseudoephedrine (4) and (R)-phenylalaninol (5). The opposite selectivity of highly regioselective oxidative ring opening of the benzaldehyde acetal of (1S,2S)-2-phthalimido-1-phenyl-1,3-propanediol by NBS and highly regioselective ring opening of the cyclic sulphite of the same substrate by LiBr are the key steps in the transformations respectively.
- Akamanchi,Ranbhan,Shah
-
p. 293 - 302
(2007/10/03)
-
- ?-Allyl palladium methodology for selective deprotection of allylamines. Practical synthesis of secondary amines
-
The palladium-promoted deallylation of allylamines derived from primary and secondary amines is achieved with high to quantitative yield in the presence of 2-mercaptobenzoic acid as an allyl scavenger.This method was used for the sequential cleavage of diallylamines.A synthetic application of this procedure is presented in the preparation of secondary amines from diallylamines. - Keywords: allylamine; deallylation; sequential deprotection; ?-allyl palladium complexes; 2-mercaptobenzoic acid; substitution of amines
- Lemarie-Audoire, Sandrine,Savignac, Monique,Dupuis, Christophe,Genet, Jean Pierre
-
p. 1157 - 1166
(2007/10/03)
-
- Saponification agents. 2. Synthesis of arylisocyanates with ethyl lactate and their use in racemic bases saponification
-
Reaction of the arylisocyanates 2a-c with ethyl (S)-(-)-lactate, followed by careful saponification, afforded the corresponding chiral acids (S)-(-)- 4a-c. The latter were successfully used for the resolution of various racemic bases belonging to both the ephedrine and α-aryl ethylamine series.
- Brown,Moudachirou
-
p. 10309 - 10320
(2007/10/02)
-
- Selective deprotective method using palladium-water soluble catalysts
-
Allylcarboxy and Allyloxycarbonyl groups can be removed without affecting dimethylallylcarboxy and cinnamylcarboxy groups in the same molecule. using Pd(O) water soluble catalyst prepared in situ, with diethylamine as allyl scavenger. Homogeneous or biphasic media are suitable: the yields of deprotection are quantitative.
- Lemaire-Audoire,Lemaire-Audoire, Sandrine,Savignac,Savignac, Monique,Blart,Blart, Errol,Pourcelot,Pourcelot, Guy,Genet,Genet, Jean Pierre,Bernard,Bernard, Jean-Marie
-
p. 8783 - 8786
(2007/10/02)
-
- Application of the Mitsunobu reaction to ephedrines and some related amino alcohols. Aspects of intramolecular participation of the amino group
-
Inversion of configuration at the benzylic hydroxyl group of (1S,2S)-pseudoephedrine (2) to afford (1R,2S)-ephedrine is known to be a difficult process.The Mitsunobu reactions of 1 and 2 might offer a route to achieve such inversions.In fact Mitsunobu reactions on 1 and 2 are known to proceed via aziridines formed on intramolecular SN2 substitution by the amine functionality.The Mitsunobu reactions of N-methylated and N-benzylated ephedrines have been found to proceed via the corresponding aziridinium ions.These aziridinium ions can be opened (SN2 substitution) by nucleophiles like phthalimide and thiols.Intramolecular participation in 2 can be avoided by use of the tert-butyloxycarbonyl-(BOC) or benzyloxycarbonyl- (CBZ) protected derivatives.Mitsunobu reactions on these derivatives lead to inversion of configuration at the benzylic hydroxyl center.In contrast the BOC and CBZ derivatives of 1 are deprotected under Mitsunobu conditions.The Mitsunobu reactions of threo (1S,2S)-2-amino-1,3-propanediol have also been examined.An attempt to achieve protection by reaction with dimethylformamide dimethyl acetal led to the more substituted 2-oxazoline as established by X-ray crystallography.The desired inversion of configuration of the benzylic hydroxylic group was eventually achieved by protection of the amino substituent as the phthalimide and protection of the primary hydroxyl group as the tosylate.
- Poelert, Martin A.,Hulshof, L. A.,Kellogg, Richard M.
-
p. 355 - 364
(2007/10/02)
-
- Method for preparing a benzaldehyde intermediate
-
A method is provided for preparing a chiral benzaldehyde of the structure STR1 by acylating an anhydride of the structure STR2 with a chiral oxazolidine of the structure STR3 where Q is MgHal or Li, and X, Y and Z are as described herein, to form a keto acid which is reduced and cyclized. The resulting benzaldehyde may be used in making the final anti-thrombotic - anti-vasospastic compounds. Novel intermediates are also provided.
- -
-
-