- Decomposition of sodium trichloroacetate in the presence of quaternary ammonium under microwave irradiation: A convenient one-pot synthesis of α-hydroxy acids in water
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A good yielding phase-transfer-catalyzed procedure for one-pot preparation of α-hydroxy acids from carbonyl compounds and sodium trichloroacetate by in situ addition and hydrolysis under microwave irradiation is described. Decomposition of sodium trichloroacetate is strongly accelerated by the presence of quaternary ammonium. The reaction can be conducted in water. Copyright Taylor & Francis Group, LLC.
- Yu, Haitao,Fang, Yun,Xia, Yongmei,Wu, Jing
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Read Online
- PRODRUGS WITH A TRIDENTATE SELF-IMMOLATIVE LINKER
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The present application provides a compound of Formula (I), or a pharmaceutically acceptable salt thereof, wherein L1, L2, L3, n, m, p, X, T, TR, and D are as described herein. Methods of using of these compounds to treat diseases advantageously treatable by drug D are also described.
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Page/Page column 56
(2020/07/08)
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- SELF-IMMOLATIVE LINKERS CONTAINING MANDELIC ACID DERIVATIVES, DRUG-LIGAND CONJUGATES FOR TARGETED THERAPIES AND USES THEREOF
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The invention provides a therapeutic drug and targeting conjugate, pharmaceutical compositions containing these conjugates in pharmaceutical composition, and uses of these conjugates in anti-neoplastic and other therapeutic regimens. Also provided are novel intermediates thereof. The conjugates provide a therapeutic drug fragment or prodrug fragment bound to a targeting moiety via a linker which comprises a substrate cleavable by a protease such as Cathepsin B. The targeting moiety is a ligand which targets a cell surface molecule, such as a cell surface receptor on an anti-neoplastic cell. The ligand may function solely as a targeting moiety or may itself have a therapeutic effect. Following administration of the therapeutic drug and targeting conjugate of formula I and exposure of the conjugate to the protease specific for the substrate, the linker is cleaved and the targeting moiety is separated from the conjugate, which causes the drug fragment or prodrug fragment to convert to the drug or prodrug. The recited conjugates are useful in anti-neoplastic therapies. Also provided are methods of making the therapeutic drug and targeting conjugates and intermediates thereof, and kits comprising the therapeutic drug and targeting conjugates.
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Page/Page column 54; 94; 95
(2015/03/28)
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- Structural aspects of nucleation inhibitors for diastereomeric resolutions and the relationship to Dutch resolution
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You say you want a resolution: Nucleation inhibitors for the resolution of diastereomers by selective crystallization have been designed and tested. The resolution of racemic 3-methoxyphenylethylamine was optimized with (S)-mandelic acid as the resolving agent (see scheme). Multifunctional inhibitors are particularly effective. (Chemical Equation Presented).
- Leeman, Michel,Brasile, Giuseppina,Gelens, Edith,Vries, Ton,Kaptein, Bernard,Kellogg, Richard
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p. 1287 - 1290
(2008/12/22)
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- Ytterbium triflate-promoted tandem one-pot oxidation-cannizzaro reaction of aryl methyl ketones
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(Chemical Equation Presented) Ytterbium triflate was shown to be an effective catalyst in promoting the synthesis of either isopropyl esters or free α-hydroxy-arylacetic acids from substituted aromatic glyoxals and aryl methyl ketones, respectively. The reaction to provide acids starting from differently substituted ketones was carried out by an environmentally friendly method using an aqueous medium as a solvent and giving the adducts in 78-99% yield without any further purification after the usual workup.
- Curini, Massimo,Epifano, Francesco,Genovese, Salvatore,Marcotullio, M. Carla,Rosati, Ornelio
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p. 1331 - 1333
(2007/10/03)
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- Chemistry of photogenerated α-hydroxy-p-nitrobenzyl carbanions in aqueous solution: Protonation vs. disproportionation
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The photochemistry of p-nitrobenzyl derivatives 6-10 has been studied in aqueous solution as a function of pH, using product analysis, UV-vis spectrophotometry, and laser flash photolysis (LFP). The compounds were chosen with the aim of further exploring the propensity of these systems to give rise to α-hydroxy-p-nitrobenzyl carbanions on photolysis, and to study their mechanisms of subsequent reaction, α-Hydroxy-substituted carbanions are anions that cannot be readily formed using thermal routes but which are believed to have some interesting chemistry. Three methods were employed for photogenerating these carbanions: (i) decarboxylation; (ii) retro-Aldol reaction; and (iii) carbon acid deprotonation. All three methods proved to be successful using the p-nitrobenzyl chromophore. Photogenerated α-hydroxy-p-nitrobenzyl carbanions react via disproportionation, giving rise to oxidized and reduced products; simple protonation of the anion was undetectable.
- Morrison, James,Wan, Peter,Corrie, John E.T.,Munasinghe, V. Ranjit N.
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p. 586 - 597
(2007/10/03)
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- pKa values for substituted acetophenones: values determined by study of rates of halogenation
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pKa values in aqueous solution have been determined for seven p-substituted acetophenones.The determinations are based on the diffusion-controlled reaction of an enolate with hypochlorous acid.The values determined for the acetophenones are as follows: substituent, value; H, 18.4; p-MeO, 19.0; p-F, 18.5; p-Cl, 18.1; p-Br, 18.0; p-NO2, 16.7; p-Me3N+, 17.1. ρ for these pKa values is -1.95.Using literature values for the enol content we show that most of this ρ value reflects substituent effects upon enolization.With relatively high hydroxide and low hypochlorite concentrations the major products from chlorination of acetophenones are the corresponding mandelic acids.Under similar conditions bromination of acetophenone gives benzoic acid.
- Guthrie, J. Peter,Cossar, John,Klym, Alex
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p. 2154 - 2159
(2007/10/02)
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- 7-α-Amino-substituted acylamino-3-(1-carboxymethyltetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acids
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Certain 7-acylamido-3-(1-carboxy-loweralkyl-tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acids and their salts and easily hydrolyzed esters of the 4-carboxyl group were synthesized and found to be potent antibacterial agents which exhibited good aqueous solubility. In a preferred embodiment the 7-substituent was 2'-aminomethylphenylacetamido.
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- 7-(D-α-Hydroxy-2-arylacetamido)-3-(2-carboxyalkyl-2,3-dihydro-s-triazolo-[4,3-b]pyridazin-3-on-6-ylthiomethyl)-3-cephem-4-carboxylic acids and derivatives
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7-(D-α-Hydroxy-2-arylacetamido)-3-(2-carboxyalkyl-2,3-dihydro-s-triazolo[4,3-b]pyridazin-3-on-6-ylthiomethyl)-3-cephem-4-carboxylic acids and derivatives containing blocking groups on the α-hydroxy group and their nontoxic, pharmaceutically acceptable salts are valuable as antibacterial agents and are particularly valuable as therapeutic agents in poultry and in animals, including man, in the treatment of infectious diseases caused by many Gram-positive and Gram-negative bacteria. A preferred compound is 7-(D-mandelamido)-3-(2-carboxyalkyl-2,3-dihydro-s-triazolo[4,3-b]pyridazin-3-on-6-ylthiomethyl)-3-cephem-4-carboxylic acid.
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- 7-(D-α-Hydroxy-2-arylacetamido)-3-(tetrazolo-[4,5-b]pyridazin-6-ylthiomethyl)-3-cephem-4-carboxylic acids
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7-(D-α-Hydroxy-2-arylacetamido)-3-(tetrazolo-[4,5-b]pyridazin-6-ylthiomethyl)-3-cephem-4-carboxylic acids and their nontoxic, pharmaceutically acceptable salts are valuable as antibacterial agents and are particularly valuable as therapeutic agents in poultry and animals, including man, in the treatment of infectious diseases caused by many Gram-positive and Gram-negative bacteria.
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