- Substituent effects in the ring-chain tautomerism of 4-alkyl-2-aryl substituted oxazolidines and tetrahydro-1,3-oxazines
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(Chemical Equation Presented) The condensation products of 2-aminoethanol or 3-aminopropanol (bearing an alkyl substituent on the carbon adjacent to the nitrogen) with substituted benzaldehydes proved to exist in CDCl3 at 300 K as three-component tautomeric mixtures of the diastereomeric five- or six-membered 1,3-O,N-heterocyclic ring forms and the corresponding imines. For each equilibrium, the electronic effects of the 2-aryl substituents were characterized by the Hammett equation. The steric effects of the alkyl groups could be described by Hansch-type equations for the equilibria involving oxazolidine ring forms. While the alkyl substituents did not cause any significant effect on the ring cis-chain and the ring trans-chain equilibria for tetrahydro-1,3-oxazines, increasing bulk of the 4-alkyl group increased the stability of the cyclic tautomers for the analogous oxazolidines.
- Juhasz, Marta,Lazar, Laszlo,Fueloep, Ferenc
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Read Online
- Six-Step Gram-Scale Synthesis of the Human Immunodeficiency Virus Integrase Inhibitor Dolutegravir Sodium
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A short and practical synthesis for preparing the active pharmaceutical ingredient dolutegravir sodium was developed. The convergent strategy starts from (R)-3-amino-1-butanol and establishes the BC ring system in a 76% isolated yield over four steps. Ring A was constructed by a one-pot 1,4-addition to diethyl-(2E/Z)-2-(ethoxymethylidene)-3-oxobutandioate and subsequent MgBr2·OEt2-mediated regioselective cyclization. Amide formation with 2,4-difluorobenzylamine was either performed from the free carboxylic acid or through aminolysis of the corresponding ethyl ester. Final salt formation afforded dolutegravir sodium in a 48-51% isolated yield (HPLC purity of 99.7-99.9%) over six linear steps.
- Dietz, Jule-Philipp,Lucas, Tobias,Gro?, Jonathan,Seitel, Sebastian,Brauer, Jan,Ferenc, Dorota,Gupton, B. Frank,Opatz, Till
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p. 1898 - 1910
(2021/08/01)
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- Refining process of R-3-amino n-butyl alcohol
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The invention discloses a refining process of R-3-amino n-butyl alcohol, and belongs to the technical field of organic chemical engineering. According to the refining process of R-3-amino n-butyl alcohol, firstly, 4-hydroxy- 2-butanone and hydroxylamine hydrochloride are adopted for an oximation reaction, then an oximation product is hydrogenated, then L-malic acid is added to form resolution salt, then absolute ethyl alcohol is utilized for refining, and after dissociation, R-3-amino n-butyl alcohol with high optical purity can be obtained. The refining process disclosed by the invention is low in cost, environment-friendly and more beneficial to industrial production.
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Paragraph 0018-0021; 0032-0040
(2021/04/07)
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- Method for preparing (R)-3-aminobutanol
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The invention provides a method for preparing (R)-3-aminobutanol, and the method comprises the following steps of: (1) providing 4-hydroxy-2-butanone and carrying out ammoniation reduction on the 4-hydroxy-2-butanone to obtain racemic 3-aminobutanol; (2) reacting (S)-mandelic acid with the racemic 3-aminobutanol to obtain resolved mandelic acid salt; and (3) alkalizing the resolved mandelic acid salt to obtain the product (R)-3-aminobutanol. According to the invention, the process of preparing the (R)-3-aminobutanol through reductive amination and salification resolution is simple and convenient to operate, low in reaction danger and pollution; the purity of the obtained (R)-3-aminobutanol reaches 99.9% (GC method).
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Paragraph 0068-0077
(2020/01/25)
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- Rapid and Quantitative Profiling of Substrate Specificity of ω-Transaminases for Ketones
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ω-Transaminases (ω-TAs) have gained growing attention owing to their capability for asymmetric synthesis of chiral amines from ketones. Reliable high-throughput activity assay of ω-TAs is essential in carrying out extensive substrate profiling and establishing a robust screening platform. Here we report spectrophotometric and colorimetric methods enabling rapid quantitation of ω-TA activities toward ketones in a 96-well microplate format. The assay methods employ benzylamine, a reactive amino donor for ω-TAs, as a cosubstrate and exploit aldehyde dehydrogenase (ALDH) as a reporter enzyme, leading to formation of benzaldehyde detectable by ALDH owing to concomitant NADH generation. Spectrophotometric substrate profiling of two wild-type ω-TAs of opposite stereoselectivity was carried out at 340 nm with 22 ketones, revealing subtle differences in substrate specificities that were consistent with docking simulation results obtained with cognate amines. Colorimetric readout for naked eye detection of the ω-TA activity was also demonstrated by supplementing the assay mixture with color-developing reagents whose color reaction could be quantified at 580 nm. The colorimetric assay was applied to substrate profiling of an engineered ω-TA for 24 ketones, leading to rapid identification of reactive ketones. The ALDH-based assay is expected to be promising for high-throughput screening of enzyme collections and mutant libraries to fish out the best ω-TA candidate as well as to tailor enzyme properties for efficient amination of a target ketone.
- Han, Sang-Woo,Shin, Jong-Shik
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p. 3287 - 3295
(2019/06/21)
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- An improved preparation of (R)-3-aminobutanol, a key intermediate for the synthesis of dolutegravir sodium
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Background: Dolutegravir sodium is a HIV-1 integrase strand transfer inhibitor (INSTI) and in combination with other anti-retroviral agents, is recommended for the treatment of HIV-1 infection. Moreover, it is a second generation HIV integrase inhibitor d
- Srinivasa Rao,Hari Babu,Aminual,Nageshwar,Satyanarayana
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p. 1371 - 1375
(2017/12/28)
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- Continuous Flow Synthesis of Morpholines and Oxazepanes with Silicon Amine Protocol (SLAP) Reagents and Lewis Acid Facilitated Photoredox Catalysis
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Photocatalytic coupling of aldehydes and silicon amine protocol (SLAP) reagents enables the simple, scalable synthesis of substituted morpholines, oxazepanes, thiomorpholines, and thiazepanes under continuous flow conditions. Key to the success of this process is the combination of an inexpensive organic photocatalyst (TPP) and a Lewis acid additive, which form an amine radical cation that is easily reduced to complete the catalytic cycle. Di- and trisubstituted SLAP reagents are formed in one step by an iron-catalyzed aminoetherification of olefins.
- Jackl, Moritz K.,Legnani, Luca,Morandi, Bill,Bode, Jeffrey W.
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supporting information
p. 4696 - 4699
(2017/09/11)
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- Asymmetric Amination of Secondary Alcohols by using a Redox-Neutral Two-Enzyme Cascade
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Multienzyme cascade approaches for the synthesis of optically pure molecules from simple achiral compounds are desired. Herein, a cofactor self-sufficient cascade protocol for the asymmetric amination of racemic secondary alcohols to the corresponding chiral amines was successfully constructed by employing an alcohol dehydrogenase and a newly developed amine dehydrogenase. The compatibility and the identical cofactor dependence of the two enzymes led to an ingenious in situ cofactor recycling system in the one-pot synthesis. The artificial redox-neutral cascade process allowed the transformation of racemic secondary alcohols into enantiopure amines with considerable conversions (up to 94 %) and >99 % enantiomeric excess at the expense of only ammonia; this method thus represents a concise and efficient route for the asymmetric synthesis of chiral amines. If you know what amine: A redox-neutral two-enzyme cascade encompassing an alcohol dehydrogenase (ADH) and an amine dehydrogenase (AmDH) is constructed for the synthesis of chiral amines from the corresponding racemic alcohols in one pot to afford considerable conversions (up to 94 %) and high enantiomeric excess values (>99 %) at the expense of only ammonia.
- Chen, Fei-Fei,Liu, You-Yan,Zheng, Gao-Wei,Xu, Jian-He
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p. 3838 - 3841
(2016/01/26)
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- AN IMPROVED PROCESS FOR THE PREPARATION OF DOLUTEGRAVIR
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The present invention provides (R)-3-Amino-1-butanol (D)-tartarate (lIb); process for its preparation and its conversion to Dolutegravir. The present invention also provides an improved process for the preparation of Dolutegravir (I) or pharmaceutically acceptable salts wherein compound (XVI) is reacted with an optically active acid addition salt of (R)-3-amino-1-butanol (lla).
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Page/Page column 23
(2014/09/03)
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- Ring opening of cyclic N,O-acetals with allyltrimethylsilane under Lewis acidic conditions
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Five and six-membered cyclic N,O-acetals with N-carboxyalkyl and sulfonyl groups undergo clean and high yielding ring opening with allyltrimethylsilane in the presence of strong Lewis acids to give homoallylic amine derivatives.
- Bates, Roderick W.,Lu, Yongna,Cai, Melody Peiling
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body text
p. 7852 - 7858
(2009/12/26)
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- Aldehyde selective Wacker oxidations of phthalimide protected allylic amines: A new catalytic route to β3-amino acids
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(Chemical Equation Presented) A new method for the synthesis of β3-amino acids is presented. Phthalimide protected allylic amines are oxidized under Wacker conditions selectively to aldehydes using PdCl2 and CuCl or Pd(MeCN)2/s
- Weiner, Barbara,Baeza, Alejandro,Jerphagnon, Thomas,Feringa, Ben L.
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supporting information; experimental part
p. 9473 - 9474
(2009/12/06)
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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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- α-methyl polyamines: Efficient synthesis and tolerance studies in vivo and in vitro. First evidence for dormant stereospecificity of polyamine oxidase
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Efficient syntheses of metabolically stable α-methylspermidine 1, α-methylspermine 2, and bis-α,α-methylated spermine 3 starting from ethyl 3-aminobutyrate are described. The biological tolerance for these compounds was tested in wild-type mice and transgenic mice carrying the metallothionein promoter-driven spermidine/spermine N1- acetyltransferase gene (MT-SSAT). The efficient substitution of natural polyamines by their derivatives was confirmed in vivo with the rats harboring the same MT-SSAT transgene and in vitro with the immortalized fibroblasts derived from these animals. Enantiomers of previously unknown 1-amino-8-acetamido-5-azanonane dihydrochloride 4 were synthesized starting from enantiomerically pure (R)- and (S)-alaninols. The studies with recombinant human polyamine oxidase (PAO) showed that PAO (usually splits achiral substrates) strongly favors the (R)-isomer of 4 that demonstrates for the first time that the enzyme has hidden potency for stereospecificity.
- J?rvinen, Aki J.,Cerrada-Gimenez, Marc,Grigorenko, Nikolay A.,Khomutov, Alex R.,Veps?l?inen, Jouko J.,Sinervirta, Riitta M.,Kein?nen, Tuomo A.,Alhonen, Leena I.,J?nne, Juhani E.
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p. 399 - 406
(2007/10/03)
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- CHIRAL FUSED [1,2]IMIDAZO[4,5-c] RING COMPOUNDS
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Fused [1,2]imidazo[4,5-c] ring compounds (e.g., imidazo[4,5-c]quinolines, 6,7,8,9-tetrahydroimidazo[4,5-c]quinolines, imidazo[4,5-c]naphthyridines, and 6,7,8,9-tetrahydroimidazo[4,5-c]naphthyridines) with a -CH(-X1-R1)-group in the fused ring at the 1-position of the imidazo ring, pharmaceutical compositions containing the compounds, intermediates, methods of making the compounds, and methods of use of these compounds as immunomodulators, for inducing cytokine biosynthesis in animals and in the treatment of diseases including viral and neoplastic diseases, are disclosed.
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Page/Page column 136
(2008/06/13)
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- Methods and compositions for treating amyloid-related diseases
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Methods, compounds, pharmaceutical compositions and kits are described for treating or preventing amyloid-related disease.
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Page/Page column 171
(2010/11/24)
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- Heterocyclic inhibitors of MEK and methods of use thereof
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Disclosed are compounds of the Formula I and pharmaceutically acceptable salts and prodrugs thereof, wherein R1, R2, R7, R8, R9 and R10, W and Y are as defined in the specification. Such compounds are MEK inhibitors and useful in the treatment of hyperproliferative diseases, such as cancer and inflammation, in mammals. Also disclosed are methods of using such compounds in the treatment of hyperproliferative diseases in mammals and pharmaceutical compositions containing such compounds.
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- Urethane-containing aminosteroid compounds
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Urethane-containing amino steroids having the general chemical formula: STR1 wherein a, b, R1, R2, R3, R4, R14 and Z are as defined in the specification. Also disclosed are pharmaceutical composition and the use of the compounds/composition in the treatment of congestive heart failure.
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- New methodology for the synthesis of unsaturated 8-, 9- and 10-membered lactams
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Unsaturated 8-, 9- and 10-membered medium ring lactams 1 (n = 1, 2, 3) have been prepared in good yield by the Claisen rearrangement of the vinyl-substituted precursors 3 in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).
- Evans, P. Andrew,Holmes, Andrew B.,McGeary, Ross P.,Nadin, Alan,Russell, Keith,O'Hanlon, Peter J.,Pearson, Neil D.
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p. 123 - 138
(2007/10/03)
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- Chemo- and diastereoselective reduction of β-enamino esters: A convenient synthesis of both cis- and trans-γ-amino alcohols and β-amino esters
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Convenient procedures for the chemo- and diastereoselective reduction of b-enamino esters 1 are described. Both cis- and trans-γ-amino alcohols 2 or b-amino esters 3 can be prepared by reduction of b-enamino esters 1, readily available starting materials, with the use of inexpensive reagents Na/i-PrOH or NaHB(OAc)3/AcOH, respectively, and the appropriate reduction conditions. The mechanisms and diastereoselectivities for the reductions are discussed. The relative configurations and conformations of the diastereoisomeric γ-amino alcohols 2 and β-amino esters 3 obtained are established by 1H and 13C NMR study and unequivocally set by their cyclic derivatives tetrahydro-1,3-oxazines 4.
- Bartoli,Cimarelli,Marcantoni,Palmieri,Petrini
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p. 5328 - 5335
(2007/10/02)
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- Regiospecific Opening of Oxetanes with Trimethylsilyl Cyanide - Zinc Iodide. A General Approach to γ-Amino Alcohols.
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Trimethylsilyl ethers of γ-hydroxy isonitriles were formed regiospecifically in the opening of oxetanes with trimethylsilyl cyanide - zinc iodide.Deprotection and hydrolysis of the initially formed ring cleavage products gave γ-amino alcohols.
- Gassman, Paul G.,Haberman, Leonard M.
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p. 4971 - 4974
(2007/10/02)
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