1010-70-4Relevant articles and documents
Synthesis and application of N-hydroxylamine derivatives as potential replacements for HOBt
El-Faham, Ayman,Albericio, Fernando
, p. 1499 - 1501 (2009)
Several heterocycles containing N-hydroxylamine were prepared and tested as coupling additives to replace the use of N-hydroxybenzolriazole (HOBt.) derivatives. On the basis of our results on coupling yield and racemization-suppressing properties, we propose N-hydroxyindolin-2-one and 6- cfiloro-N-hydroxy-2-phenylbenzimidazole as suitable substitutes for HOBt. Wiley-VCH Verlag GmbH & Co. KGaA.
Metal complexes of cyclic hydroxamates. Synthesis and crystal structures of 3-hydroxy-2-methyl-3H-quinazolin-4-one (ChaH) and of its Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes
Alagha, Ahmed,Parthasarathi, Laavanya,Gaynor, Declan,Müller-Bunz, Helge,Starikova, Zoya A.,Farkas, Etelka,O'Brien, Eimear C.,Gil, Marie-Jose,Nolan, Kevin B.
, p. 58 - 66 (2011)
The attempted acetylation of anthranilic hydroxamic acid (2-aminobenzohydroxamic acid) as a possible dual inhibitor of the catalytic sites in prostaglandin-H-synthase (PGHS) gave the cyclic hydroxamic acid 3-hydroxy-2-methyl-3H-quinazolin-4-one (ChaH) which was characterised by spectroscopy and X-ray crystallography. The length of the hydroxamic acid C-N bond, 1.3998(17) ?, in ChaH is longer than normal (～1.33 ?) indicative of reduced delocalisation of the nitrogen lone pair of electrons into the hydroxamic acid π system. This is confirmed by the appearance of the ν(CO) band at a considerably higher wavenumber in the IR spectrum than normal. The complexes Fe(Cha)2(Cl)(H2O) ·7/2H2O, Co(Cha)2(EtOH) 2, Ni(Cha)2(EtOH)2, Cu(Cha)(H2O)(Cl) and Zn(Cha)2(H2O), have been synthesised and their structures determined by X-ray crystallography. The X-ray data confirmed coordination by Cha- through the carbonyl and deprotonated hydroxamate oxygen in all cases. The M-O (hydroxamate) bonds are shorter than the M-O (carbonyl) bonds by between 0.0930 ? for the Co(II) complex and 0.0448 ? for the Ni(II) complex. The geometries of all complexes conform to the coordination requirements of the particular metal ion involved. Speciation studies for ChaH and its complexes with Ni(II) and Zn(II) were carried out using pH-metric methods. The results show that ChaH is much more acidic than related acyclic hydroxamic acids and that its metal complexes are correspondingly less stable.
PROTON ACCEPTOR IMINIUM/CARBOCATION-TYPE COUPLING AGENTS
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, (2010/06/19)
Novel iminium-type coupling agents containing proton acceptors in their iminium moiety, which can be used beneficially as coupling agents in various chemical polypeptide and/or polynucleotide syntheses, and are particularly useful as yield enhancing and racemization suppressing coupling agents for use in peptide syntheses, are disclosed. Further disclosed are a process of preparing such iminium-type coupling agents and their use in the preparation of polypeptides and/or polynucleotides.
Fragment-based lead discovery: Screening and optimizing fragments for thermolysin inhibition
Englert, Lisa,Silber, Katrin,Steuber, Holger,Brass, Sascha,Over, Bjoern,Gerber, Hans-Dieter,Heine, Andreas,Diederich, Wibke E.,Klebe, Gerhard
experimental part, p. 930 - 940 (2011/02/24)
Fragment-based drug discovery has gained a foothold in today's lead identification processes. We present the application of in silico fragment-based screening for the discovery of novel lead compounds for the metalloendoproteinase thermolysin. We have chosen thermolysin to validate our screening approach as it is a well-studied enzyme and serves as a model system for other proteases. A protein-targeted virtual library was designed and screening was carried out using the program AutoDock. Two fragment hits could be identified. For one of them, the crystal structure in complex with thermolysin is presented. This compound was selected for structure-based optimization of binding affinity and improvement of ligand efficiency, while concomitantly keeping the fragment-like properties of the initial hit. Redesigning the zinc coordination group revealed a novel class of fragments possessing Ki values as low as 128 μm, thus they provide a good starting point for further hit evolution in a tailored lead design.
Synthesis of new fused hetecrocyclic compounds of benzpyrid-4-one derivatives and their some biological activity
Soleiman,Koraiem,Mahmoud
, p. 553 - 560 (2007/10/03)
A series of fused pyrazolino-, Isoxazolino-, Pyrimidino-, Pyrimidinothino-, thiazolidinones and β-lactam incorporating benzpyrid-4-one derivatives have been synthesized by different methods of chemical reaction. The prepared compounds were established by universals and modern methods of physical and chemical confirmation.
Reactions of 3-hydroxy-1,2-dihydroquinazolin-4-ones with acid chlorides
Luk'yanov,Gordeev
, p. 1335 - 1338 (2007/10/03)
The reactions of 3-hydroxy-1,2-dihydroquinazolin-4-ones with acid chlorides can afford compounds of different types. The structures of the products depend on the type of acid chloride used and on the nature of the substituent at position 2 of the 3-hydroxy-1,2-dihydroquinazolin-4-one.
Unexpected formation of cyclic hydroxamic acids from O-(2-aminobenzoyl) hydroxylamine
Sahadeva Reddy,Shailaja,Pratap Reddy,Reddy
, p. 2843 - 2846 (2007/10/03)
Cyclic hydroxamic acids 3 and 4 are the unexpected products in the reaction of O-(2-aminobenzoyl) hydroxylamine 1 and orthoesters, acid chlorides, ethyl chloroformate.
