Complexation of N-bis[2-(1,2-dicarboxyethoxy)ethyl]aspartic acid with Fe(II), Co(II), and Ni(II) in aqueous solution

In a search for environment-friendly metal chelating ligands for industrial applications, the protonation and complex formation equilibria of N-bis[2-(1,2-dicarboxyethoxy)ethyl]aspartic acid (BCA6) with Fe(II), Co(II), and Ni(II) ions in aqueous 0.1 M NaCl solution were studied at 25°C by potentiometric titration. The model for complexation and the stability constants of different complexes were determined for each metal ion using SUPERQUAD. In all cases, complex formation was dominated by stable ML^4? complexes.     

Complexation of N-bis[2-(1,2-dicarboxyethoxy)ethyl]aspartic acid with Cd(II), Hg(II) and Pb(II) ions in aqueous solution

The persistence of widely used chelating agents EDTA and DTPA in nature has been of concern and there is a need for ligands to replace them. In a search for environmentally friendly metal chelating ligands for industrial applications, complex formation equilibria of N-bis[2-(1,2-dicarboxyethoxy)ethyl]aspartic acid (BCA6) with Cd(II), Hg(II) and Pb(II) in aqueous 0.1 M NaNO₃ solution were studied at 25°C by potentiometric titration. Complexation was modeled and the stability constants of the different complexes were determined for each metal ion using the computer program SUPERQUAD. With all metal ions, stable ML^4? complexes dominated the complex formation. The stabilities of Cd(II), Hg(II) and Pb(II) chelates of BCA6 are remarkably lower than those of EDTA and DTPA. Environmental advantages of the use of BCA6 instead of EDTA and DTPA are better biodegradability and lower nitrogen content with a possibility to save chemicals and process steps in pulp bleaching.     

Complexation of N-tris[(1,2-dicarboxyethoxy)ethyl]amine with Ca(II), Mn(II), Cu(II) and Zn(II) in aqueous solution

In a search for environmentally friendly metal chelating ligands for industrial applications, the protonation and complex formation equilibria of N-tris[(1,2-dicarboxyethoxy)ethyl]amine (TCA6) with Ca(II), Mn(II), Cu(II) and Zn(II) ions in aqueous 0.1?M NaCl solution were studied at 25°C by potentiometric titration. A model for complexation and stability constants of the complexes were determined. With all of the metals, complex formation was dominated by ML^4?. Comparison of TCA6 and six other chelating agents showed TCA6 to be suitable for applications where strong calcium binding is essential.     

N-[1-(取代苯基)乙基]-2-羟基苯甲酰肼的合成、表征及抑菌活性

依据邻羟基二苯醚及芳香肼类化合物的抗菌特性, 以邻羟苯基为分子核心, 酰肼键为桥基, 设计合成了7种未见报道的N-(取代苯基)乙基-2-羟基苯甲酰肼类化合物. 以水杨酸甲酯为原料, 经肼解反应后与取代苯乙酮缩合, 再与硼氢化钠反应制得目标化合物, 化合物结构经IR, ¹H NMR和元素分析等证实. 抗菌活性测试结果表明, 该类化合物对不同菌株的抑菌活性具有明显的选择性和特异性. 当质量浓度为1×10^-4 g/mL时, 化合物3b和3e对大肠杆菌和白色念珠菌的抑菌率高达100%, 有极强的抑菌活性; 所有化合物对金黄色葡萄球菌的抑菌率均大于70%, 有一定的抑菌活性. 构效关系分析结果表明, 苯基中引入Cl或Br等卤原子能显著增强化合物的抑菌活性, 而引入-NO₂及-CH₃基团则会降低其抑菌活性.     

(1R,3S,4S)-2-苄氧羰基-2-氮杂双环[2.2.1]庚烷-3-羧酸的合成

以(R)-(+)-α-甲基苄胺为原料,依次经缩合,Diels-Alder反应,还原,Cbz-保护和水解反应,合成了抗丙肝新药HCV NS3/4A蛋白酶拟肽类抑制剂的重要中间体——(1R,3S,4S)-2-苄氧羰基-2-氮杂双环[2.2.1]庚烷-3-羧酸,总收率66%,其结构经1H NMR和ESI-MS确证。     

4,4'-二(对氨基苯乙炔基)-6,6'-二[N,N-二(乙氧基羰甲基)氨甲基]-2,2'-联吡啶的合成与表征

以4,4'-二硝基-2,2'-联吡啶-6,6'-二亚甲基双三氟乙酸酯作为起始原料, 经水解、 溴化、 酯化和对氨基苯乙炔取代4步反应合成了4,4'-二(对氨基苯乙炔基)-6,6'-二[N,N-二(乙氧基羰甲基)氨甲基]-2,2'-联吡啶. 通过红外光谱、 核磁共振波谱、 高分辨质谱等表征了该化合物的结构. 该化合物经水解后与铕离子形成稀土荧光螯合物, 在紫外光激发下, 发射出具有铕离子特征的荧光光谱.     

First synthesis of 2-[alkylamino(diethoxyphosphoryl)methyl]acrylic ethyl esters

The ethyl α-bromomethyl-β-(diethoxyphosphoryl)acrylic acid ester 9 has been prepared by addition of bromine to allylphosphonate 7 then dehydrobromination with DBU in acetonitrile. Reaction of allylic bromide 9 with primary amines in a bimolecular S_N2′-type mecanism in methanol at low temperature, gives rise to the 2-[alkylamino(diethoxyphosphoryl)methyl]acrylic acid ethyl esters 6.     

A Convenient Method for Synthesis of Novel Cyclic Ethers (1R,2R,3R,5S,7S,9R,12R)-3-(t-Butyldimethylsilyl)oxy-7-methoxymethyl-oxy-2,10-dimethyl-12-oxatricyclo [7.2.1.0~(5,12)] dodecane

Coloradocin, a novel macrolide antibiotic from cultures of Actinoplanes coloradoensis1exhibits activity against pathogenic anaerobic and microaerophilic species2. Because itslow toxicity and substantial oral activity3, , as well as its unusual structure5, several 4research groups initiated approaches towards the synthesis of coloradocin6, whichculminated in the synthesis of 18-deoxynargenicin A1 by Kallmerten et al.7. …     

1-(3,5-二甲基苯基)-1-[(1S,4S)-1,7,7-三甲基双环[2.2.1]庚烷-2-基]肼的合成工艺改进

以3,5-二甲基苯胺和2-莰酮为起始原料,在微波促进下,经缩合反应制得N-(3,5-二甲基苯基)-1-(1S,4S)-1,7,7-三甲基二环[2.2.1]庚烷-2-亚胺(1);1经硼氢化钠还原后再与羟胺-O-磺酸经胺化反应合成了1-(3,5-二甲基苯基)-1-[(1S,4S)-1,7,7-三甲基双环[2.2.1]庚烷-2-基]肼,总收率70.4%,其结构经1H NMR和ESI-MS确证。     

Synthesis and Crystal Structure of N-[(3aR,4R,4aR,5aS,6S,6aS)-1,3-Dioxooctahydro-4,6-ethenocyclopropa[f]lisoindol-2(1H)-yl]-3-(trifluoromethyl)phenylmethanimine

The crystal structure of the title compound (C19H15F3N2O2, Mr= 360.33) was determined by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P(1), with a = 6.5604(7), b = 13.9614(16), c = 18.1790(18) (A), α = 102.749(7),β = 97.542(6), γ = 94.355(4)°, V= 1600.5(3) (A)3, Z = 4, Dc = 1.495 g/cm3, λ(MoKα) = 0.71070, F(000) = 744, μ(MoKα) = 0.122mm-1, R = 0.0434 and wR = 0.1051. A total of 7590 unique reflections were collected, of which 5429 with |F|2 ≥ 2σ|F|2 were observed. The two cyclohexene rings in the molecule adopt boat-boat conformations with the deviations of ring atoms C(9) and C10 from the C(5)/C(6)/C(7)/C(8) plane (Ⅰ) by 1.1204 (0.0023) and 1.1132 (0.0023) (A), respectively, whereas from the C(2)/C(3)/C(5)/C(8)plane (Ⅱ) by 1.1627 (0.0022) and 1.1818 (0.0021) (A), respectively. In the cyclopropane and lactam rings, atoms C(11) and N(1) point towards the double bond of C(9)-C(10) and the dihedral angle between the ring plane (Ⅲ) containing C(1), C(2), C(3) and C(4) and plane (Ⅳ) consisting of C(6),C(7) and C(11) is 55.76 (0.07)°. The dihedral angles between planes Ⅳ and Ⅰ and Ⅱ and Ⅲ are 63.58 (0.07)° and 58.10 (0.06)°, respectively. The dihedral angle between the benzene ring C(13)～C(18) and plane Ⅳ is 42.41 (0.06)°.     

Synthesis and characterization of N′-(11H-indeno[1,2-b]quinoxalin-11-ylidene)benzohydrazonamides as potential antimicrobial agents

Abstract

A series of new N′-(11H-indeno[1,2-b]quinoxalin-11-ylidene)benzohydrazonamides 3a–3j was synthesized in excellent yields from the reaction of N³-substituted benzohydrazonamides 1 and 2-(11H-indeno[1,2-b]quinoxalin-11-ylidene)malononitrile 2 in dichloromethane or with 11H-indeno[1,2-b]quinoxalin-11-one 4 in ethyl acetate at ambient temperature. The new compounds have been characterized and screened for biological activity. Some of them showed significant antibacterial and antifungal activities. In particular, compounds 3c and 3e showed interesting activities as antibacterial agents while compounds 3a 3c, 3e, 3g, and 3i showed high antifungal activities.     

Synthesis and Crystal Structure of （2S,5S）-1-Aza-2-（2-pyridyl）-3-oxa-4,4-diphenylbicyclo [3.3.0] Octane

1 INTRODUCTION The catalytic asymmetric synthesis has been a challenging subject in organic synthesis. The deve- lopment of efficient enantioselective catalysts appli- cable to a wide range of carbon-carbon bond form- ing reactions represents a pivotal …     

Reaction of imidazole series aldeydes with bis[2-(2-pyridyl)ethyl]-phosphine chalcogenides: Synthesis of polyfunctional heterocyclic systems

The nucleophilic addition of bis[2-(2-pyridyl)ethyl]phosphine sulfide and bis[2-(2-pyridyl)-ethyl]phosphine selenide to 2-formyl-1-organylimidazoles and benzimidazoles occurs efficiently without catalysis at room temperature to give functionalized heterocyclic compounds containing imidazole, benzimidazole, and pyridine rings and also chalcogenophosphoryl and hydroxyl groups. Dedicated to Professor A. Pozharskii on his 70th jubilee Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1669–1675, November, 2008.     

SYNTHESIS AND APPLICATION OF 2-(ARYLAZO)-8-NITRONAPHTHO[1,2-d] THIAZOLE DISPERSE DYES

Abstract

The paper describes the synthesis of 2-amino-8-nitronaphtho[1,2d]thiazole and its utilization to prepare a range of heterocyclic azo disperse dyes. These arylazo dyes were studied with respect to their color and constitution relationship. These dyes were applied on polyester fibre and their fastness properties were evaluated.     

4-甲基-苯磺酸-2-氧-2-[3-(5-芳基-[1,3,4]噁二唑-2-基)-硫脲]-乙基酯的合成及生物活性研究

合成了12个未见文献报道的4-甲基-苯磺酸2-氧-2-[3-(5-芳基-[1,3,4]噁二唑-2-基)-硫脲]-乙基酯, 其结构经元素分析、¹H NMR和IR确证. 初步活性测试结果表明: 部分化合物有较好的杀菌活性.     

(1R,2R)-(+)-(1,2)-DPEN-Bonded Sulfonic Acid Resin: A Trifunctional Heterogeneous Catalyst for Asymmetric Michael Additions of Acetone to Nitroolefins

Based on (1R,2R)-(+)-(1,2)-DPEN skeleton, a series of primary amine–sulfamide bifunctional catalysts were synthesized, which exhibited excellent catalytic performance in the Michael addition of acetone to β-nitrostyrene. Therefore, a trifunctional heterogeneous catalyst was designed and prepared by simple N-sulfonyl reaction of (1R,2R)-(+)-(1,2)-DPEN and sulfonyl chloride resin. It was employed for the aforementioned addition without any additive and satisfactory results (80.5% conversion; 84.3% ee) were obtained. Meanwhile, the structural and textural properties of the catalyst were characterized by infrared spectroscopy (FT-IR), elemental analysis, SEM, and N₂ adsorption and desorption experiments. Finally, the generality of the catalyst was investigated.     

Reactions of cyclic 1,3-dicarbonyl compounds with 1,2(1,4)-dihydro-1-methyl-2(4)-methylene-N-heterocycles. A new access to 6,12-methano-dibenz[d,g]-[1,3]oxazocinones

Summary The enamine-type methylene-N-heterocycles1–5 react with cyclic 2-ethoxymethylene-1,3-dicarbonyl compounds6 to give 2-[2-(hetarylidene)ethylidene]-1,3-dicarbonyl compounds7–14. The result of the reactions between 1,2-dihydro-1-methyl-2-methylene-quinoline (1a) and cyclic 1,3-dicarbonyl compounds depends on the nature of the dihydro intermediatesA/B. Dehydrogenation of keton intermediatesA results in 2-(1,2-dimethyl-4(1H)-quinolylidene)-1,3-dicarbonyl compounds17–21. Enol intermediatesB with 6-membered dicarbonyl ring form 6,12-methano-dibenz-[d,g][1,3]oxazocinones22–25.¹H NMR spectra and X-ray structure analysis prove the structure of23.

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Reaktionen cyclischer 1,3-Dicarbonylverbindungen mit 1,2(1,4)-Dihydro-1-methyl-2(4)-methylen-N-heterocyclen. Ein neuer Zugang zu 6,12-Methano- dibenz[d,g][1,3]oxazocinonen

Zusammenfassung Aufgrund ihres Enamincharakters reagieren die Methylen-N-heterocyclen1–5 mit cyclischen 2-Ethoxymethylen-1,3-dicarbonylverbindungen6 zu den 2-[2-(Hetaryliden)ethyliden]-1,3-dicarbonylverbindungen7–14. Das Ergebnis der Reaktionen zwischen 1,2-Dihydro-1-methyl-2-methylen-chinolin (1a) und cyclischen 1,3-Dicarbonylverbindungen hängt von der Natur der zwischenzeitlich entstehenden DihydroverbindungenA/B ab. Die Intermediat-KetoneA gehen durch Dehydrierung während der Reaktion in die 2-(1,2-Dimethyl-4(1H)chinolyliden)-1,3-dicarbonylverbindungen17–21 über. Die Intermediat-EnoleB mit sechsgliedrigem Dicarbonylring bilden in intramolekularer Reaktion die 6,12-Methano-dibenz[d,g][1,3]oxazocinone22–25, deren Struktur am Beispiel der Verbindung23 durch¹H-NMR sowie durch Röntgenkristallstrukturanalyse bewiesen wird.

     

Synthesis of 5-[2-(Phenoxy)ethyl] Derivatives of 6-Methyluracil, 6-Methyl-2-thioxo-2,3-dihydro-1H-pyrimidin-4-one,and 2-Imino-6-methyl-2,3-dihydro-1H-pyrimidin-4-one

A synthesis of novel derivatives of 6-methyluracil, 6-methyl-2-thioxo-, and 2-imino-6-methyl-2,3-dihydro-1H-pyrimidin-4-one containing a 2-(phenoxy)ethyl substituent at position 5 of the pyrimidine ring has been carried out. It was found that 5-[2-(phenoxy)ethyl] derivatives of 6-methyl-2-thioxo- and 2-imino-6-methyl-2,3-dihydro-1H-pyrimidin-4-one are obtained by the condensation of the corresponding ethyl 3-oxo-2-(2-phenoxyethyl)butanoates with thiourea or guanidine. 6-Methyl-5-[2-(phenoxy)ethyl]uracils can be prepared by treating 6-methyl-5-[2-(phenoxy)ethyl]-2-thioxo-2,3-dihydro-1H-pyrimidin-4-ones with an excess of aqueous monochloroacetic acid solution. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1213–1217, August, 2005.     

Poly[2-(N,N-Dimethylamino) Ethyl Methacrylate] /Poly(Styrene-Co-Methacrylic Acid) Interpolymer Complexes

Summary: Poly[2-(N,N-dimethylamino)ethyl methacrylate] (PDMAEMA), copolymers of different compositions of styrene with 2-(N,N-dimethylamino)ethyl methacrylate (SDMAEMA) or methacrylic acid (SMA) were synthesized by free radical polymerization and characterized by several techniques. Different ternary mixtures containing proton-acceptors PDMAEMA or SDMAEMA, proton-donor copolymers SMA and a solvent (butan-2-one or THF) were prepared. The present study, that investigated several factors that affected the phase behaviors of the ternary mixtures above, confirmed that, indeed depending on the nature of solvent, densities of interacting species, amounts of efficient specific interactions that occurred between the two copolymers, interpolymer complexes of different structures were elaborated. The complexation phenomena, observed with these different systems were analyzed in solution by viscometry that confirmed these effects in monitoring the formation of interpolymer complexes. The specific interactions that occurred between pairs of polymers of each system above were qualitatively evidenced by FTIR spectroscopy from the appearance of new bands or their new redistribution. The glass transition temperature Tg of the obtained complexes of different structures determined by DSC varied differently with the weight fraction of one of the copolymers. These various Tg-compositions were analyzed using the Kwei and Brostow et al. approach recently developed. Thermal analysis of some of the elaborated complexes, examined by thermogravimetry, confirmed their improved thermal stability.