排序方式: 共有23条查询结果,搜索用时 31 毫秒
1.
Robert Andreu Gerard Lligadas Joan Carles Ronda Marina Galià Virginia Cádiz 《Journal of polymer science. Part A, Polymer chemistry》2007,45(21):4965-4973
A new oxazolidine derivative was obtained from phenol, 2‐amino‐2‐methylpropane‐1,3‐diol and paraformaldehyde. The reaction of this novel oxazolidine diol with phenylisocyanate lead to a urethane model compound which can be polymerized thermally by oxazolidine ring opening to give a Mannich bridge structure. Linear segmented polyurethanes were prepared by reaction of different ratios of oxazolidine diol and commercial polyethylenglycol (Mw ~ 400) with 4,4′‐methylenbis (cyclohexylisocyanate) (HMDI, 90% isomers mixture). The polyurethanes were thermally characterized and crosslinked by oxazolidine ring opening to obtain materials which showed improved thermal stability. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4965–4973, 2007 相似文献
2.
Oligonucleotides modified by a 2′-deoxy-2′-(N-methoxyamino) ribonucleotide react readily with aldehydes in slightly acidic conditions to yield the corresponding N-(methoxy)oxazolidine-linked oligonucleotide-conjugates. The reaction is reversible and dynamic in slightly acidic conditions, while the products are virtually stable above pH 7, where the reaction is in a ‘‘switched off-state’’. Small molecular examinations have demonstrated that aldehyde constituents affect the cleavage rate of the N-(methoxy)oxazolidine-linkage. This can be utilized to adjust the stability of this pH-responsive cleavable linker for drug delivery applications. In the present study, Fmoc-β-Ala-H was immobilized to a serine-modified ChemMatrix resin and used for the automated assembly of two peptidealdehydes and one aldehyde-modified peptide nucleic acid (PNA). In addition, a triantennary N-acetyl-d-galactosamine-cluster with a β-Ala-H unit has been synthesized. These aldehydes were conjugated via N-(methoxy)oxazolidine-linkage to therapeutically relevant oligonucleotide phosphorothioates and one DNA-aptamer in 19–47% isolated yields. The cleavage rates of the conjugates were studied in slightly acidic conditions. In addition to the diverse set of conjugates synthesized, these experiments and a comparison to published data demonstrate that the simple conversion of Gly-H to β-Ala-H residue resulted in a faster cleavage of the N-(methoxy)oxazolidine-linker at pH 5, being comparable (T0.5 ca 7 h) to hydrazone-based structures. 相似文献
3.
Martina Astrová Ladislav Kurc Libor erveny 《Reaction Kinetics and Catalysis Letters》2006,89(2):311-318
Summary Condensation of ephedrine with benzaldehyde, an acid catalyzed reversible reaction, producing 3,4-dimethyl-2,5-diphenyl-1,3-oxazolidine,
was studied. If the starting reaction mixture contained acetic acid, it quantitatively reacted with ephedrine and produced
a salt functioning as an acid catalyst. On the contrary, ephedrine hydrochloride had no catalytic effect. 相似文献
4.
A series of novel N-dichloroacetyl oxazolidine herbicide safeners was synthesized and characterized by IR, 1H NMR, 13C NMR, elemental analysis and X-ray diffraction. The preliminary biological test shows that the compounds could protect maize against injury caused by chlorsulfuron to a certain extent. 相似文献
5.
L. M. Kostochka V. P. Lezina M. L. Kostochka 《Chemistry of Heterocyclic Compounds》2003,39(9):1227-1230
We obtained 3-(2-aryloxazolidin-3-yl)tropanes by reaction of aromatic aldehydes with 3-[N-(2-hydroxyethyl)amino]tropane. We obtained 3-benzyloxazolidine-2-spiro-3'-(8'-carbethoxy)nortropane by reaction of benzylaminoethanol with 8-carbethoxynortropan-3-one. 相似文献
6.
Zahra Mardani Mohammad Hakimi Keyvan Moeini Fabian Mohr 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(7):951-959
The reaction between 2‐[2‐(aminoethyl)amino]ethanol and pyridine‐2‐carbaldehyde in a 1:2 molar ratio affords a mixture containing 2‐({2‐[(pyridin‐2‐ylmethylidene)amino]ethyl}amino)ethanol (PMAE) and 2‐[2‐(pyridin‐2‐yl)oxazolidin‐3‐yl]‐N‐(pyridin‐2‐ylmethylidene)ethanamine (POPME). Treatment of this mixture with copper(II) chloride or cadmium(II) chloride gave trichlorido[(2‐hydroxyethyl)({2‐[(pyridin‐2‐ylmethylidene)amino]ethyl})azanium]copper(II) monohydrate, [Cu(C10H16N3O)Cl3]·H2O or [Cu(HPMAE)Cl3]·H2O, 1 , and dichlorido{2‐[2‐(pyridin‐2‐yl)oxazolidin‐3‐yl]‐N‐(pyridin‐2‐ylmethylidene)ethanamine}cadmium(II), [CdCl2(C16H18N4O)] or [CdCl2(POPME)], 2 , which were characterized by elemental analysis, FT–IR, Raman and 1H NMR spectroscopy and single‐crystal X‐ray diffraction. PMAE is potentially a tetradentate N3O‐donor ligand but coordinates to copper here as an N2 donor. In the structure of 1 , the geometry around the Cu atom is distorted square pyramidal. In 2 , the Cd atom has a distorted octahedral geometry. In addition to the hydrogen bonds, there are π–π stacking interactions between the pyridine rings in the crystal packing of 1 and 2 . The ability of PMAE, POPME and 1 to interact with ten selected biomolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS, Top II and B‐DNA) was investigated by docking studies and compared with doxorubicin. 相似文献
7.
Tsutomu Oishi Kenjiro Onimura Kazumi Tanaka Wataru Horimoto Hiromori Tsutsumi 《Journal of polymer science. Part A, Polymer chemistry》1999,37(4):473-482
Asymmetric anionic homopolymerizations of achiral N‐substituted maleimides (RMI) were performed with lithium 4‐alkyl‐2,2‐dialkyloxazolidinylamide. All obtained polymers were optically active, exhibiting opposite optical rotation to that of a corresponding oxazolidinyl group at the terminal of the main chain. This suggests that opposite optical rotation to the corresponding chiral oxazolidine was induced to the polymer main chain. In the polymerization using a fluorenyllithium (FlLi)–oxazolidine complex, the obtained polymer with a fluorenyl group at the polymer end showed a negative specific rotation. This also suggests that asymmetric induction took place in the polymer main chain. The asymmetric induction was supported by the circular dichroism (CD) and GPC analysis with polarimetric detector. Optical activity of the polymer was attributed to different contents of (S,S) and (R,R) structures formed from threo‐diisotactic additions, as supported by the 13C‐NMR spectra of the polymers and the model compounds. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 473–482, 1999 相似文献
8.
Telechelic poly(1,3-oxazolidine-acetal)s with -CH2OH and -CHO groups were synthesized by polycondensation of the 2-amino-2-hydroxy-1,3-propanediol ( 1 ) (TRIS) with terephthaldehyde ( 2 ). The degree of polymerization (DP) was controlled by the ratio of 1 to 2 at the given reaction time. Characterization was achieved by 1H and 13C NMR and IR spectroscopy. The distribution of oxazolidine-acetal units in the polymer chain has been performed using ESI-MS. The activities of telechelic poly(oxazolidine-acetal) were determined in reaction oxidation (4-chloroperbenzoic acid), reduction (CH3MgCl) and nucleophilic substitution (acylation, alkylation). 相似文献
9.
M. Madesclaire P. Coudert V. P. Zaitsev Yu. V. Zaitseva 《Chemistry of Heterocyclic Compounds》2004,40(10):1310-1314
The interaction of (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediol with a series of symmetrical ketones has been studied. As a result isomeric oxazolidines are formed in a ratio of 85:15. These oxazolidines were shown to decompose readily under the action of hydrazine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1518–1523, October, 2004. 相似文献
10.
Yanmei Wang Hisatoyo Morinaga Atsushi Sudo Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2011,49(8):1881-1886
A metharylate monomer having an octanal‐derived bicyclo bisoxazolidine (BBOX) moiety was synthesized and was radically copolymerized with a methacrylate having a hydrophilic poly(ethylene glycol) chain to obtain an amphiphilic copolymer having the BBOX moieties as hydrophobic side chains. The BBOX moieties were stable for 7 days at pH 7.0, whereas they were gradually hydrolyze at pH 5.0 to release octanal continuously for 7 days, confirming the potential applicability of the copolymer to a polymeric pro‐fragrance that can release aldehyde‐type fragrance molecules slowly for a long period. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献