- Photometric Characterization of the Reductive Amination Scope of the Imine Reductases from Streptomyces tsukubaensis and Streptomyces ipomoeae
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Imine reductases (IREDs) have emerged as promising enzymes for the asymmetric synthesis of secondary and tertiary amines starting from carbonyl substrates. Screening the substrate specificity of the reductive amination reaction is usually performed by time-consuming GC analytics. We found two highly active IREDs in our enzyme collection, IR-20 from Streptomyces tsukubaensis and IR-Sip from Streptomyces ipomoeae, that allowed a comprehensive substrate screening with a photometric NADPH assay. We screened 39 carbonyl substrates combined with 17 amines as nucleophiles. Activity data from 663 combinations provided a clear picture about substrate specificity and capabilities in the reductive amination of these enzymes. Besides aliphatic aldehydes, the IREDs accepted various cyclic (C4–C8) and acyclic ketones, preferentially with methylamine. IR-Sip also accepted a range of primary and secondary amines as nucleophiles. In biocatalytic reactions, IR-Sip converted (R)-3-methylcyclohexanone with dimethylamine or pyrrolidine with high diastereoselectivity (>94–96 % de). The nucleophile acceptor spectrum depended on the carbonyl substrate employed. The conversion of well-accepted substrates could also be detected if crude lysates were employed as the enzyme source.
- Matzel, Philipp,Krautschick, Lukas,H?hne, Matthias
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p. 2022 - 2027
(2017/10/07)
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- A facile preparation of N-methylpentan-l-amine: A key intermediate for ibandronate sodium
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A facile preparation of N-methylpentan-l-amine, which is a key intermediate for the synthesis ibandronate sodium, an anti-osteoclast agent is described. This route is cost effective over the previous methods. Part of this work could be an easy access for the preparation of various N,N-alkyl or aryl amine derivatives.
- Reddyab, V V R M Krishna,Chintamani,Udaykiran,Madhusudhan,Mukkanti
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experimental part
p. 1257 - 1260
(2010/12/24)
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- PROCESS FOR THE SYNTHESIS OF IBANDRONATE SODIUM
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The present invention relates to an improved process for the synthesis of Ibandronate sodium of formula (I). The present invention also provides novel processes for the synthesis of 3-[N-(methylpentyl)amino]propionic acid (III).
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Page/Page column 6-7
(2010/08/07)
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- CRYSTALLINE FORM A OF IBANDRONIC ACID AND PROCESS FOR THE PREPARATION
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The present invention relates crystalline Form A of Ibandronic acid having Formula (I) and a process for the preparation thereof.
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Page/Page column 25-26; 26-27
(2008/06/13)
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- PROCESS FOR PREPARING IBANDRONATE
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The invention relates to a novel multi step synthesis of 3-(N-methyl-N-pentyl)amino-1-hydroxypropane-1,1-diphosphonic acid, monosodium salt, monohydrate, of the formula
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Page/Page column 2
(2008/12/04)
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- 2,3,4,5-TETRAHYDRO-1H-1,5-BENZODIAZEPINE DERIVATIVE AND MEDICINAL COMPOSITION
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The present invention has its object to provide a 2,3,4,5-tetrahydro-1H-1,5-benzodiazepine derivative represented with the Formula (1) , or the pharmaceutically acceptable salt, which is effective as a therapeutic and prophylactic agent for diabetes, diabetic nephropathy, or glomerulosclerosis.
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- Method for synthesizing bisphosphonate
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The invention relates to a novel multi step synthesis of 3-(N-methyl-N-pentyl) amino-1-hydroxypropane-1,1-diphosphonic acid, monosodium salt, monohydrate, of the formula
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Page/Page column 2-3
(2008/06/13)
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- Preparation process of aminoacetamide derivative
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Disclosed herein are novel processes for preparing aminoacetamide derivatives, wherein: (1) a secondary amine is reacted with a 2-haloacetamide in the presence or absence of at least one solvent selected from water, lower alcohols, aromatic solvents and acetic acid esters; (2) an N-benzylideneamine derivative is reacted with dimethyl sulfate or diethyl sulfate to form a secondary amine, and this secondary amine is then reacted with a 2-haloacetamide; and (3) a primary amine is reacted with benzaldehyde to form an N-benzylideneamine derivative, this product is then reacted with dimethyl sulfate or diethyl sulfate to form a secondary amine, and this secondary amine is further reacted with a 2-haloacetamide. The 2-aminoacetamide derivatives are useful as intermediates for the preparation of novel antibiotics.
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- Transformation of Monoamine Oxidase-B Primary Amine Substrates into Time-Dependent Inhibitors. Tertiary Amine Homologues of Primary AMine Substrates
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A family of N-methylated and N,N-dimethylated alkyl and arylalkylamines was prepared and more than half of the analogues were shown to be time-dependent pseudo-first-order inhibitors of monoamine oxidase-B.Some of the time-dependent inactivators were reversible and others were irreversible with respect to prolonged dialysis following inactivation.Partition ratios ranged from zero to 11 000.These results are rationalized in terms of a combination of an inductive effect and a stereoelectronic effect as a result of hindered rotation of an active site covalent adduct.A molecualr mechanics calculation indicates that there is at least 10 kcal/mol of torsional energy to be overcome in order for the enzyme adduct to be released.These findings show that tertiary amine homologues of primary amine substrates of monoamino oxidase are time-dependent inhibitors, and this should be useful in the design of new inactivators of this enzyme.
- Ding, Charles Z.,Lu, Xingliang,Nishimura, Kuniko,Silverman, Richard B.
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p. 1711 - 1715
(2007/10/02)
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- ELECTROCHEMICAL REDUCTIVE AMINATION. II. AMINATION OF ALIPHATIC ALDEHYDES WITH PRIMARY AMINES
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The formation of a secondary amine by the electrolysis of an aqueous solution containing an aldehyde and a primary amine was studied.The formation of the secondary amines passes through the intermediate stage of an aldimine.The highest yield of secondary amine is attained at a molar ratio of primary amine to aldehyde of 1.2:1.As electrode material lead, cadmium, zinc, and copper may be used.As supporting electrolyte a phosphate buffer with a pH close to the pKa of the primary amine is recommended.By the method developed 32 amines with various structures were synthesized.
- Smirnov, Yu. D.,Pavlichenko, V. F.,Tomilov, A. P.
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p. 374 - 380
(2007/10/02)
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- Highly Selective Aromatic Chlorination. Part 3. Kinetics and Mechanism of Chlorination of Electron-rich Aromatic Compounds by N-Chloroamines in Acidic Solution
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The highly selective chlorination of electron-rich aromatic compounds with N-chloroamines in trifluoroacetic acid (TFA) is first order in both the aromatic substrate and the chlorinating agent.Kinetic and competitive kinetic studies show that electron-donating substituents on the substrate and electron-withdrawing substituents on the N-chloroamine have a marked rate-enhancing effect.Two mechanisms that fit the experimentally observed kinetics and that account for the high selectivity for 4-chlorination in terms of an electronic effect are proposed, namely an arenium-ion mechanism and an electron-transfer chain reaction.Evidence from chemical trapping experiments and from other studies suggest that for the majority of the substrates the chlorination proceeds by the arenium ion mechanism.However, for substrates, such as 1,4-dimethoxybenzene, that are very susceptible to one-electron oxidation chlorination may proceed at least in part by the electron-transfer chain reaction.
- Smith, John R. Lindsay,McKeer, Linda C.,Taylor, Jonathan M.
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p. 1529 - 1536
(2007/10/02)
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- A New Synthesis of Imines via Grignard- and Cuprate Additions to N-Trimethylsilylformamides
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Various imines and some amines were synthesized by the addition of Grignard reagents, homo- and hetero-cuprates to N-silylated-, N-alkyl-, or N-arylformamides 1.
- Feringa, Ben L.,Jansen, Johan F. G. A.
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p. 184 - 186
(2007/10/02)
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- POLAR RADICALS XVIII. ON THE MECHANISM OF CHLORINATION BY N-CHLOROAMINES: INTERMOLECULAR AND INTRAMOLECULAR ABSTRACTION.
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The photochlorinations of the n-butyl, n-pentyl, and n-hexyltrimethylammonium chlorides, using molecular chlorine in hexachloroacetone or 15percent CD3CO2D/85percent H2SO4, or using N-chlorodimethylamine in the acid solvent are described.The ammonium group exerted a strong polar directing effect upon the site of substitution.This effect was found to be more pronounced in the more polar protic solvent.The reagent, N-chlorodimethylamine, generated the dimethylamminium radical, whose reaction showed a polar sensitivity toward hydrogen abstraction similar to that of the chlorine atom, but exhibiting a much greater secondary/primary selectivity.Comparison of the isomer distributions obtained from the self photochlorination reactions of N-chloro-n-hexylmethylamine and N-chloro-n-pentylmethylamine in the acid solvent, with the distribution pattern obtained for the chlorinations of the ammonium salts with N-chlorodimethylamine, suggested that the self chlorinations of the N-chloroamines proceed by the intramolecular hydrogen abstraction mechanism suggested previously.
- Tanner, Dennis D.,Arhart, Richard,Meintzer, Christian P.
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p. 4261 - 4278
(2007/10/02)
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- Competing Hydride Transfer and Ene Reactions in the Aminoalkylation of 1-Alkenes with N,N-Dimethylmethyleniminium Ions. A Literature Correction
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A literature report that N,N-dimethylmethyleniminium ion (2) reacts with propylene and styrene to form unsaturated tertiary amines is shown to be incorrect.The major products are the secondary amines 1-(methylamino)butane and 1-(methylamino)-3-phenylpropane in which N-demethylation has occurred along with the saturation of the alkene.Analogous major products are formed with 1-butene, 1-hexene, 1-octene, 1-dodecene, 1-tetradecene, p-methylstyrene, and m-nitrostyrene as substrates.When the substrates are isobutylene, 2-ethyl-1-hexene, α-methylstyrene, and p-methoxystyrene, the major products are tertiary amines, but the secondary amines are also formed in smaller yields.The small yields of tertiary amines obtained in the cases of styrene and p-methylstyrene were increased by going from solvent acetic acid to acetonitrile and by increasing the branching of the alkyl groups on nitrogen.The internal olefins 5-decene and cyclohexene were far less reactive, giving only 3-4percent of amine products that were mainly tertiary in the former case and secondary in the latter.It is concluded that tertiary amine products are favored by an alkene structure and a solvent that favors the formation of a stable carbenium ion intermediate or a transition state with substantial carbenium ion character upon electrophilic attack of the iminium ion on the alkene.The secondary amine products are favored when a carbenium ion is of low stability and when the β-carbon atom of the olefin and/or the alkyl group attached to nitrogen is sterically unhindered; such hindrance decreases the rate of hydride ion transfer that is believed to occur in the production of secondary amines.
- Cohen, Theodore,Onopchenko, Anatoli
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p. 4531 - 4537
(2007/10/02)
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