- STUDY ON THE REACTION OF MONOFUNCTIONAL FLUORESCENT REAGENTS IN ORGANIC SOLUTIONS BY FLUOROMETRY.
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Reactions of some fluorescent reagents with substrates, used widely in biochemistry for quantitative analysis of some functional groups in aqueous media, have been studied in organic solutions with a view that they may be used also in the area of synthetic polymer science. Reactions studied by fluorometry were (i) 5-dimenthylamino-1-naphtalensulfonyl chloride with butylamine, (ii) 2-naphthalensulfonyl chloride with butylamine, and (iii) N-(1-naphthyl)maleimide with 1-pentanethiol. In polar solvents all the fluorescent probes studied are too labile and converted spontaneously into fluorescent compounds. In less polar solvents, however, such side reactions do not take place and the reaction of fluorescent reagents with substrates proceeds quantitatively with a simple second-order kinetics. The second-order rate constants for the three reactions are of the order of 10** minus **3 to 10** minus **1 M** minus **1 s** minus **1 in the range of about 30 to 50 degree C, and they increase with the solvent polarity. This work is pertinent to polymers.
- Okamoto,Uchiyama,Mita
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- Graphene Oxide as a Carbocatalyst for a Diels–Alder Reaction in an Aqueous Medium
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The Diels–Alder (DA) reaction, a [4+2] cycloaddition reaction, is highly important in synthetic organic chemistry and is frequently used in the synthesis of natural products containing six-membered rings. Herein, we report an efficient protocol for the DA reaction between 9-hydroxymethylanthracene and N-substituted maleimides using two-dimensional graphene oxide (GO) as a heterogeneous carbocatalyst in an aqueous medium at room temperature. High yields, a wide substrate scope, low temperature, excellent functional group tolerance, atom economy, and water as a green solvent are noteworthy features of this protocol. The heterogeneous GO catalyst can be easily recovered and used multiple times without any significant loss in catalytic activity.
- Girish, Yarabhally R.,Pandit, Subrata,Pandit, Subhendu,De, Mrinmoy
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supporting information
p. 2393 - 2398
(2017/09/11)
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- DABCO-catalyzed [3+2] cycloaddition reactions of azomethine imines with N-aryl maleimides: Facile access to dinitrogen-fused heterocycles
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DABCO-catalyzed [3+2] cycloaddition of azomethine imines with maleimides has been developed. This method could efficiently furnish dinitrogen-fused tetracyclic heterocycles in high levels of regioselectivity and with good yields.
- Jia, Qianfa,Chen, Lei,Yang, Gongming,Wang, Jian,Wei, Jia,Du, Zhiyun
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supporting information
p. 7150 - 7153
(2015/12/12)
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- Synthesis and evaluation of hexahydropyrrolo[3,4-d]isoxazole-4,6-diones as anti-stress agents
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A series of 2,3-diphenyl-5-(naphthalen-1-yl)-4H-2,3,3a,5,6,6a- hexahydropyrrolo[3,4-d]isoxazole-4,6-dione derivatives were synthesized via 1,3-dipolar cycloaddition of azomethine N-oxides with N-(α-naphthyl) maleimide. The pyrrolo-isoxazole derivatives were assigned cis- and trans- configurations (3-A and 3-B) with respect to proton C3-H on azomethinic carbon on the basis of their 1H NMR. The reaction proceeds through cis- endo addition rule indicating the predominance of cis isomer. The cis- and trans- isomers of a prototype compound 3a i.e., compound 3a-A and compound 3a-B were evaluated for anti-stress activity in immobilization-induced acute stress. Compound 3a-A (5 and 10 mg/kg) and compound 3a-B (10 mg/kg) attenuated immobilization stress-induced behavioral alterations in Swiss albino mice suggesting that pyrrolo-isoxazole may serve as lead molecule for the development of anti-stress agents.
- Badru, Rahul,Anand, Preet,Singh, Baldev
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experimental part
p. 81 - 91
(2012/03/22)
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- Comparison of microwave-assisted and conventional preparations of cyclic imides
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Microwave-assisted preparation of several cyclic imides was performed with four different cyclic anhydrides. All the reactions are significantly faster and the isolated yields are significantly higher compared to conventionally heated reactions. Furthermore, many of these reactions can be performed with a minimal amount of solvent, thereby enabling the synthetic chemist to obtain high quantities of pure cyclic imides in a matter of hours.
- Upadhyay, Sunil K.,Pingali, Subramanya R.K.,Jursic, Branko S.
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experimental part
p. 2215 - 2217
(2010/05/18)
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- Discovery and structural optimization of pyrazole derivatives as novel inhibitors of Cdc25B
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Structural optimization and preliminary structure-activity relationship studies of a series of N-substituted maleimide fused-pyrazole analogues with Cdc25B inhibitory activity, starting from a high-throughput screening hit, are illustrated. A simplified 3,5-diacyl pyrazole analogue was obtained as the most potent compound (118, IC50 = 0.12 μM) with a 270-fold increase in potency.
- Chen, Hai-Jun,Liu, Yong,Wang, Li-Na,Shen, Qiang,Li, Jia,Nan, Fa-Jun
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scheme or table
p. 2876 - 2879
(2010/07/04)
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- AIBN initiated free radical homopolymerization of N-(1-naphthyl)maleimide and copolymerization with MMA: Synthesis and characterization
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Free radical homopolymerization of N-(1-naphthyl)maleimide (NMI) and copolymerization with MMA were performed in THF at 65°C with AIBN as the initiator. Nine copolymer samples were prepared using different feed ratios of comonomers. The prepared polymer sample have been characterized by solubility test, intrinsic viscosity, FT-IR and 1H NMR spectral analysis. The thermal properties have been studied by thermo-gravimetric analysis.
- Hiran,Chaudhary, Jyoti,Meena, Suresh,Paliwal, Shiv Narayan
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experimental part
p. 607 - 614
(2009/07/18)
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- Synthesis and characterization of new compounds containing 1,4-dithiintetracarboxydiimide units
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New compounds containing 1,4-dithiintetracarboxydiimide units were synthesized by the disubstitution reaction of N-substituted 2,3- dichloromaleimide with sodium sulflde nonahydrate or thiourea. IR, UV-vis and 1H-NMR spectroscopy, as well as elemental analysis, confirmed their structures. Thermal conversion of 1,4-dithiine ring to thiophene was monitored by differential calorimetry (DSC) and thermogravimetric (TGA) measurements.
- Gǎinǎ, Constantin
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p. 601 - 607
(2007/10/03)
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- Fluorescence and aggregation behavior of poly(amidoamine) dendrimers peripherally modified with aromatic chromophores: The effect of dendritic architectures
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PAMAM dendrimers of the zeroth to fifth generation (G0-5) have been peripherally modified with phenyl, naphthyl, pyrenyl, and dansyl chromophores. Their fluorescence behaviors are strongly affected by the dendritic architectures at different generations.
- Wang, Bing-Bing,Zhang, Xin,Jia, Xin-Ru,Li, Zi-Chen,Ji, Yan,Yang, Ling,Wei, Yen
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p. 15180 - 15194
(2007/10/03)
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- Organic reactions in ionic liquids: Ionic liquid-promoted efficient synthesis of N-alkyl and N-arylimides
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In the ionic liquids [Bmim][PF6] or [Bmim][BF4], a series of succinimide, maleimide and phthalimide derivatives were synthesized from corresponding anhydrides with a variety of primary amines in excellent yield.
- Le, Zhang-Gao,Chen, Zhen-Chu,Hu, Yi,Zheng, Qin-Guo
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p. 995 - 998
(2007/10/03)
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- Non-hydroxylic clathrate hosts of [4 + 2]π cycloadducts of phencyclone and N-arylmaleimides: Recognition of aromatic guests
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A series of non-hydroxylic crystalline host compounds, [4 + 2]π cycloadducts of phencyclone and N-arylmaleimides having a bicyclo[2.2.1]heptene-7-one system, was synthesized and their inclusion behavior investigated. X-Ray crystal analyses of the inclusion compounds of the N-(1-naphthyl) derivative with butan-2-one, the N-(m-tolyl) derivative with p-xylene, together with the guest-free host and the N-(p-tolyl) derivative with m-xylene indicate that the "space" surrounded by the phenanthrene ring, two phenyl rings and bridge carbonyl of the 1,3-diphenyl-1,3-dihydrocyclopenta[l]phenanthren-2-one moiety plays an important role, not only in the formation of inclusion complexes with the aromatic guests but also in host-host interactions. In every case, the N-aryl succinimide assists complex formation with the guests, in which the weak lattice forces due to C-H ... π and C-H ... O interactions are operative. Methyl-substituted benzenes are effectively recognized by the C-H ... π interactions between the guest molecules and the phenanthrene ring of the hosts.
- Yoshitake, Yasuyuki,Misaka, Junichi,Setoguchi, Koji,Abe, Masaki,Kawaji, Tomohiro,Eto, Masashi,Harano, Kazunobu
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p. 1611 - 1619
(2007/10/03)
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- Thermal Cycloaddition of N-Arylmaleimides to Phenols: the Convenient Synthesis of Bicyclooct-2-en-5-one and Tricyclo2,8>octan-2-one Derivatives from Phenols
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Monohydric phenols undergo 2,5-thermal cycloaddition of N-substituted maleimides to give bicyclooct-2-en-5-ones.Homopolymers of the maleimides are also concurrently formed, except in the case of N-(2,6-dimethylphenyl)maleimide: this is the preferred addend and gave a 63percent yield of the 2,5-adduct as a mixture of exo and endo isomers.U.v. irradiation in acetone of the diester (16) derived from the endo adduct of phenol and N-phenylmaleimide gave the tricyclo2,8>octan-3-one (17) in quantitative yield.
- Bryce-Smith, Derek,Gilbert, Andrew,McColl, Ian S.,Drew, Michael G. B.,Yianni, Paul
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p. 1147 - 1152
(2007/10/02)
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