- Efficient Synthesis of N-Sulfonyl β -Arylmethylalaninates from Serine via Ring Opening of N-Sulfonyl Aziridine-2-carboxylate
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We report the efficient synthesis of N-sulfonyl β-arylalanines methyl ester through regioselective ring opening of N-protected aziridines by variety of heteroaryl C-nucleophiles. We have optimized synthesis of N-protected aziridines with versatile protecting groups to afford 4a-c, 6a, and 6b with moderate to good yields using sulfuryl chloride, triethyl amine, and toluene at -50 °C. The present work reports on the studies related to electronic effect of nitrogen substituent on aziridination from the inexpensive starting material DL-serine. The present investigation also reports the efficient synthesis of N-sulfonyl β-arylmethylalaninates (7a-e and 8a-e) by regioselective nucleophilic ring opening of N-sulfonamido-protected aziridines using various aryl moieties such as C-nucleophiles and Lewis acids (InCl3, FeCl3, Cu(OTf)2) as catalysts and some trials by ring opening using Grignard reagent. GRAPHICAL ABSTRACT.
- Chaudhari, Prashant,Bari, Sanjay
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supporting information
p. 401 - 412
(2015/10/29)
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- Primary amino acid derivatives: Compounds with anticonvulsant and neuropathic pain protection activities
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Pharmacological management remains the primary method to treat epilepsy and neuropathic pain. We have advanced a novel class of anticonvulsants termed functionalized amino acids (FAAs). In this study, we examine FAA derivatives from which the terminal acetyl moiety was removed and termed these compounds primary amino acid derivatives (PAADs). Twenty-seven PAADs were prepared; the central C(2) R-substituent was varied, including C(2) stereochemistry, and the compounds were tested in rodent models of seizures and neuropathic pain. C(2)-Hydrocarbon N-benzylamide PAADs were potent anticonvulsants and excellent anticonvulsant activity (mice, ip; rat, po) was observed for C(2) R-substituted PAADs in which the R group was ethyl, isopropyl, or tert-butyl, and the C(2) stereochemistry conformed to the d-amino acid configuration ((R)-stereoisomer). These values surpassed the activities of several clinical antiepileptic drugs. The C(2) (R)-ethyl and C(2) (R)-isopropyl PAADs also displayed excellent activities in the mouse (ip) formalin neuropathic pain model. Significantly, unlike the FAA structure-activity relationship, PAAD anticonvulsant activity increased upon substitution of a methylene unit for a heteroatom in the R-substituent that was one atom removed from the C(2) site, suggesting that these PAADs function by a different pathway than FAAs.
- King, Amber M.,Salomé, Christophe,Dinsmore, Jason,Salomé-Grosjean, Elise,De Ryck, Marc,Kaminski, Rafal,Valade, Anne,Kohn, Harold
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p. 4815 - 4830
(2011/10/01)
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- Radiolabelling via fluorination of aziridines
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This invention relates to novel compounds comprising arziridine ring suitable for labelling or already labelled with an appropriate halogen, preferably 18F, methods of preparing such compounds, compositions comprising such compounds, kits comprising such compounds or compositions and uses of such compounds, compositions or kits for diagnostic imaging, preferably positron emission tomography (PET).
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- Regio- and stereoselective lithiation of terminal oxazolinylaziridines: The aziridine N-substituent and the oxazolinyl group effect
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The regioselective lithiation of terminal oxazolinylaziridines has been investigated. The steric hindrance of the nitrogen substituent in 1-trityl-2-oxazolinylaziridine 3a, combined with the coordinating ability of the oxazolinyl group, causes β-lithiatio
- Luisi, Renzo,Capriati, Vito,Di Cunto, Peppino,Florio, Saverio,Mansueto, Rosmara
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p. 3295 - 3298
(2008/02/12)
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- Unnatural amino acids. 3*. Aziridinyl ketones from esters and amides of aziridine-2-carboxylic acids
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A series of N-substituted amides and esters of aziridine-2-carboxylic acids have been prepared and have been subjected to deprotonation with lithium diisopropylamide. The intermediate carbanions reacted more readily with the carbonyl groups of the substrates than with methyl iodide. So, in place of the expected amides or esters of methylaziridine-2-carboxylic acids, amides or esters of 2-aziridinylcarbonylaziridine-2-carboxylic acids were isolated.
- Shtrumfs,Hermane,Kalvinsh,Trapencieris
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p. 169 - 174
(2008/12/21)
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- Reduction of 2-acylaziridines by samarium(II) iodide. An efficient and regioselective route to β-amino carbonyl compounds
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A convenient method for the reduction of 2-acylaziridines, aziridine-2- carboxylates and aziridine-2-carboxamides is described. The reduction of all of the substrates examined was extremely rapid and highly regioselective, giving rise to β-amino carbonyl compounds. This method appears to be general for all of the classes of aziridines mentioned above, and also tolerates a variety of nitrogen protecting groups.
- Molander, Gary A.,Stengel, Peter J.
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p. 8887 - 8912
(2007/10/03)
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- L-aminodicarboxylic-(O-cycloalkyl)-L-aminocarboxylate alkyl ester sweeteners
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Dipeptides of certain α-amino dicarboxylic acids and etherified hydroxy α-amino-mono-carboxylic acid esters possess a high order of sweetness. These dipeptides have the following formula: STR1 wherein R is alkyl containing 1-3 carbon atoms; R1
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- L-aminodicarboxylic acid amides of alkoxyalkylamines
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The present invention is directed to new sweeteners of the formula: STR1 wherein, A is H, alkyl containing 1-3 carbon atoms, hydroxyalkyl containing 1-3 carbon atoms, alkoxymethyl wherein the alkoxy group contains 1-3 carbon atoms, or CO2 R in
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- L-aminodicarboxylic acid amides
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Amides of α-aminodicarboxylic acids and β-aminoethers are low calorie sweetners.
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- FORMATION D'AZIRIDINES DANS KF/ACETONITRILE - OBTENTION DE 3-FLUORO AMINO-ACIDES PAR OUVERTURE AVEC HF/Py
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Synthesis of 1-trityl-2-phenylaziridine, 1-trityl-2-methylaziridine and 2-methylcarboxylates of 1-tritylaziridine, 1-trityl-3-methylaziridine, 1-trityl-3-phenylaziridine by reacting N-triphenylmethyl-α-chloroamines and methyl esters of N-triphenylmethyl-O
- Barama, Akila,Condom, Roger,Guedj, Roger
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p. 183 - 188
(2007/10/02)
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