共查询到20条相似文献,搜索用时 15 毫秒
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L. A. Shemchuk V. P. Chernykh O. S. Krys’kiv 《Russian Journal of Organic Chemistry》2006,42(3):382-387
Anthranilic acid amide reacts with cyclic anhydrides to give the corresponding N-acyl derivatives at the amino group, while analogous reactions of o-aminobenzohydroxamic acid lead lead to formation of 3-hydroxy-quinazolin-4-ones under mild conditions. N-Acyl derivatives of anthranilic acid amide undergo intramolecular cyclization to imides on microwave irradiation or on melting, and their treatment with acetic anhydride in the presence of sodium acetate on heating yields quinazolin-4-ones. 相似文献
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Natsuhiro Azuma Fumio Sanda Toshikazu Takata Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1997,35(6):1007-1012
Cationic copolymerization of seven-membered cyclic sulfite, 1,3,2-dioxathiepane-2-oxide (1) and oxetane (2) in one-shot feeding was carried out to obtain the corresponding copolymer. When a mixture of equimolar amount of 1 and 2 reacted at 0°C in the presence of methyl trifluoromethanesulfonate (T fOMe) as a cationic initiator, T fOMe and 2 were completely consumed without the consumption of 1. After rising the polymerization temperature up to 25°C, 1 started to be consumed to obtain the corresponding copolymer of 1 and 2. The obtained copolymer showed a unimodal GPC curve, and it afforded a polyether showing a unimodal GPC after alkaline hydrolysis. These results strongly suggested the occurrence of the block copolymerization in one-shot feeding. From the molecular orbital examination, the formation of block copolymerization in one-shot feeding was discussed to be caused by the much larger polymerizability of 2 than that of 1. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1007–1012, 1997 相似文献
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Tomomi Nagasawa Bungo Ochiai Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2007,45(8):1388-1393
Infrared (IR) thermography was employed to monitor temperature changes during the copolymerization of a spiroorthoester monomer with an oxetane monomer initiated with a benzyl sulfonium salt. The temperature changes in the polymerizations decreased with the increase of the initial feed ratios of the spiroorthocarbonate monomer. For instance, the temperature in the copolymerization of the equimolar mixture of both of the monomers increased only ~1 °C, whereas that in the homopolymerization of the oxetane monomer increased more than 20 °C. This result indicates that the copolymerization employing spiroorthocarbonate monomers effectively suppress temperature increase, which are responsible to shrinkage during cooling. The suppression of polymerization shrinkage by spiroorthocarbonate was also confirmed by density measurement of the polymers using a gas pycnometer. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1388–1393, 2007. 相似文献
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D. R. Fagerburg 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(8):853-858
This work reports attempts to extend to unsaturated anhydrides the rapid reaction of dicarboxylic acid anhydrides with ethylene carbonate to form polymer directly. The reaction of unsaturated diacid anhydrides with two cyclic carbonates, ethylene and propylene carbonate, leads to gelled products whenever the anhydride is capable of Michael addition, while an anhydride without such unsaturation gave linear polymer in- stead. The GC/MS results, along with efforts to trap radical reactions, support Michael addition as an explanation of gelation in these systems. 相似文献
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Sergio Rosselli 《Tetrahedron letters》2006,47(39):7047-7050
The first natural occurring cyclic carbonate terpenoid, the guaianolide hololeucin (1), was isolated from the aerial part of Centaurea hololeuca. Its structure was elucidated on the basis of extensive proton, 13C and two-dimensional NMR experiments, as well as by transformation in its diacetyl derivative. 相似文献
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Kohki Ebitani Masaki Kato Ken Motokura Tomoo Mizugaki Kiyotomi Kaneda 《Research on Chemical Intermediates》2006,32(3):305-315
Montmorillonite-enwrapped titanium hydroxide species (Ti4+-mont) acted as a highly efficient heterogeneous acid catalyst for the acylation of aromatic compounds with acid anhydrides
or carboxylic acids. The catalytic activity of the Ti4+-mont was higher than those of other acid catalysts such as zeolites, SO
4
2−
/ZrO2 and p-toluenesulfonic acid. For example, the reaction of anisole with dodecanoic acid in the presence of the Ti4+-mont catalyst gave 1-(4-methoxyphenyl)-1-dodecanone in 97% yield. Furthermore, the Ti4+-mont catalyst was easily separated from the reaction mixture and was recyclable. 相似文献
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Kohki Ebitani Masaki Kato Ken Motokura Tomoo Mizugaki Kiyotomi Kaneda 《Research on Chemical Intermediates》2006,32(3-4):305-315
Montmorillonite-enwrapped titanium hydroxide species (Ti4+-mont) acted as a highly efficient heterogeneous acid catalyst for the acylation of aromatic compounds with acid anhydrides or carboxylic acids. The catalytic activity of the Ti4+-mont was higher than those of other acid catalysts such as zeolites, SO 4 2? /ZrO2 and p-toluenesulfonic acid. For example, the reaction of anisole with dodecanoic acid in the presence of the Ti4+-mont catalyst gave 1-(4-methoxyphenyl)-1-dodecanone in 97% yield. Furthermore, the Ti4+-mont catalyst was easily separated from the reaction mixture and was recyclable. 相似文献
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Toshinobu Higashimura Toshio Masuda Seizo Okamura 《Journal of polymer science. Part A, Polymer chemistry》1969,7(4):1115-1129
Copolymerizations of 3,3-bis(chloromethyl)oxetane (BCMO) with some vinyl compounds were carried out with cationic catalysts in various solvents to determine what kind of vinyl compound is able to copolymerize with BCMO. p-Methylstyrene (pMS), 2-chloroethyl vinyl ether (CEVE), α-methylstyrene (αMS), and isobutene (IB) were used as comonomers. The rate of consumption of each monomer was measured by gas chromatrography. Plots of copolymer composition in the copolymerization of BCMO with pMS were characterized by S-shaped curves in several solvents. As poly-BCMO is insoluble and the vinyl polymers are soluble in benzene, the polymers obtained were separated into benzene-soluble and benzene-insoluble fractions, and the composition of each fraction was determined by elemental analysis. It was found that pMS, CEVE and IB formed a copolymer with BCMO, but αMS produced no copolymer with BCMO. Thus the formation of copolymer between a cyclic ether and some vinyl monomers was observed by a cationic mechanism. The cross-propagation mechanism is discussed on the basis of these results. 相似文献
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E. B. Belikova G. I. Borodkin T. I. Savina M. M. Shakirov B. G. Shubin Yu. L. Yagupol'skii 《Russian Chemical Bulletin》1991,40(5):1108-1108
The protonation of unsaturated organic compounds is one of the general methods for the generation of carbocations. Strong Brönsted acids in which a hydrogen atom is attached directly to an atom having high electronegativity (O, Hal) are usually employed for this purpose. We found that CH acids can also be used for the generation of carbocations.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1231–1232, May, 1991. 相似文献
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Sevil DinçerVolkan Köseli Hande KesimZakir M.O Rzaev Erhan Pi?kin 《European Polymer Journal》2002,38(11):2143-2152
Radical-initiated copolymerization of N-isopropylacrylamide (NIPA) with maleic (MA) and citraconic (CA) anhydrides was carried out in the presence of 2,2′-azobisisobutyronitrile (AIBN) as an initiator in 1,4-dioxane at 65 °C under nitrogen atmosphere. Structure and monomer unit compositon of the copolymers obtained from a wide range of monomer feed were determined by elemental analysis (content of N for NIPA units), Fourier transform infrared and 1H NMR spectroscopy. Monomer reactivity ratios for NIPA (M1)-MA (M2) and NIPA (M1)-CA (M2) pairs were determined by Kelen-Tüdõs (KT) and non-linear regression (NLR) methods using elemental and 1H NMR spectroscopy analyses data. They are r1=0.45 and r2=0.08 (KT, N analysis), r1=0.44 and r2=0.10 (KT, 1H NMR), r1=0.45 and r2=0.078 (NLR) for NIPA-MA monomer pair and r1=0.52 and r2=0.02, r1=0.44 and r2=0.04, r1=0.51 and r2=0.014 for NIPA-CA monomer pair, respectively. Observed tendency towards alternating copolymerization at ?50 mol% NIPA concentration in monomer feed and relatively high activity of NIPA growing radical was explained by H-bond formation between CO (anhydride) and NH (amide) fragments during chain growth reactions. Intrinsic viscosity, molecular weight and thermal behaviour of the synthesized copolymers were found to depend on the type of comonomer and the amount of NIPA units in the copolymers. These functional amphiphilic copolymers containing anion- and cation-active groups show both temperature and pH sensitivity and can be used for biological purposes as physiologically active macromolecular systems. 相似文献
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J. S. Yadav B. V. S. Reddy K. Sadashiv K. Harikishan A. V. Narsaiah 《Journal of molecular catalysis. A, Chemical》2004,220(2):153-157
Aziridines smoothly react with acid anhydrides in the presence of a catalytic amount of scandium triflate under mild reaction conditions to afford the corresponding β-aminoacetates, benzoates and propionates in high yields with high regioselectivity. 相似文献