离子液体中13-芳基-5,7,12,14-四氢二苯并[b, i]氧杂蒽5,7,12,14(13H)-四酮衍生物的绿色高效合成

在离子液体[bmim+][BF4-]中高产率的合成了一系列13-芳基-5,7,12,14-四氢二苯并[b, i]氧杂蒽-5,7,12,14(13H)-四酮类化合物。该反应操作步骤简单,离子液体易于与产物分离,并且离子液体可以循环使用。     

Xanthene Dye Chemiluminescence for Determination of Free Chlorine in Water

Abstract

Preliminary investigations by a batch method are described for aiming at the flow determination of free chlorine in water with novel chemiluminescence (CL) detection. The CL originates from the reaction of xanthene dyes with free chlorine, Cl₂, HOCl, and OCl^?. Through the measurements of CL decay curves, fundamental CL characteristics were explored from the analytical point of view. Among xanthene dyes tested, eosin Y. eosin B. pyronin B. and rhodamine 6G were found to be promising CL reagents with such sensitivity and selectivity that free chlorine can be readily determined in tap water. In particular. these CL systems have the special advantage of being insensitive to oxo acids of chlorine and chloramine. Recommended flow systems are proposed.     

9,9-二[4-(4-羧基苯氧基)苯基]呫吨的合成

在碘化亚铜、四丁基溴化铵和磷酸钾存在下,9,9-二(4-羟基苯基)呫吨(1)和4-甲基碘苯(2)于N,N-二甲基甲酰胺溶剂中发生Ullmann偶联反应,加热回流反应24 h,以95%的产率合成了中间体--9,9-二[4-(4-甲基苯氧基)苯基]呫吨(3),继而加入催化量的N-溴代丁二酰亚胺并在光照条件下,将中间体3氧化得到一种新型芳香族二羧酸--9,9-二[4-(4-羧基苯氧基)苯基]呫吨(4),其产率为84%,二步反应总收率为79.8%。 目标化合物4经1H NMR、13C NMR、IR和元素分析测试技术确定了其结构。 该法具有原料易得,操作简单,反应条件温和,收率高等优点。     

Pulsed laser ablated zeolite nanoparticles: A novel nano-catalyst for the synthesis of 1,8-dioxo-octahydroxanthene and N-aryl-1,8-dioxodecahydroacridine with molecular docking validation

There is an increasing interest in the synthesis of metal nanoparticles (NPs) from bulk metals using pulsed laser ablation in liquids (PLAL), as it offers an easy and simple synthesis route. In this work, zeolite NPs (molecular sieve 4A) were successfully synthesized by the PLAL technique, and characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, and high-resolution transmission electron microscopy. Data obtained confirm the formation of the crystalline phase of zeolite. The synthesized catalyst (zeolite molecular sieve 4A) was used as an efficient and facile promotor for the synthesis of xanthene and acridine derivatives. Molecular docking of the synthesized compounds was validated using quinone reductase 2 (NQO2) and acridine orange as the ligand, with the synthesized molecules showing good drug–ligand interaction on the active site of NQO2, compared with that of acridine orange.     

氨基恶唑啉呫吨类BACE1抑制剂的特征结构与作用机制

β-分泌酶(BACE1)是治疗阿尔兹海默症(AD)的潜在靶点,BACE1抑制剂的开发已成为治疗AD的重要方向。本文运用比较分子相似性指数(CoMSIA)和分子对接法对66个氨基恶唑啉呫吨类BACE1抑制剂进行模拟分析,建立了可靠的构效关系预测模型(Q₂=0.86, R_ncv2=0.97, R_pre2=0.88),揭示了影响分子抑制活性的重要特征结构信息,发现抑制剂通过与BACE1之间形成的氢键作用和π-π堆积作用占据了分泌酶的S3、S1和S2"三个活性位点。实验所得模型和信息为后续新型高效BACE1抑制剂的结构优化和改造提供了重要的理论指导。     

Photopolymerization of Butyl Methacrylate in the Presence of Nanoparticles of ZnO,Sensitized to Visible Light with Xanthene Dyes

The photopolymerization of butyl methacrylate in isopropanol with participation of nanoparticles of wide-gap semiconductor ZnO has been studied. The possibility of sensitizing ZnO nanoparticles to visible light with a series of halogenated fluoresceins has been established. The rate of photoinitiation of polymerization in the systems studied is principally determined by the rate of electron transfer from the photoexcited molecule of the sensitizer into the conduction zone of the semiconductor nanoparticles.     

Phosphomolybdic acid supported on Schiff base functionalized graphene oxide nanosheets: Preparation,characterization, and first catalytic application in the multi‐component synthesis of tetrahydrobenzo[a]xanthene‐11‐ones

New Schiff base (SB) functionalized graphene oxide (GO) nanosheets containing phosphomolybdic counter‐anion H₂PMo₁₂O₄₀^¯ (H₂PMo) were successfully prepared by grafting of 3‐aminopropyltriethoxysilane (APTS) on GO nanosheets followed by condensation with benzil and finally reaction with phosphomolybdic acid (H₃PMo₁₂O₄₀, denoted as H₃PMo) and characterized using Fourier transform infrared (FT‐IR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), particle size distribution, energy‐dispersive X‐ray (EDX) analysis, EDX elemental mapping, and inductively coupled plasma optical emission spectrometry (ICP‐OES). The prepared new nanomaterial, denoted as GO‐SB‐H₂PMo, was shown to be an efficient heterogeneous catalyst in one‐pot, three‐component reaction of β‐naphthol, aldehydes, and dimedone, giving high yields of tetrahydrobenzo[a]xanthene‐11‐ones within short reaction times. The catalyst is readily recovered by simple filtration and can be recycled and reused several times with no significant loss of catalytic activity.     

Synthesis and Characterization of New Soluble Polyamides from 9,9-Bis[4-(chloroformylphenoxy)phenyl]xanthene and Various Aromatic Diamines

9,9‐Bis(4‐hydroxyphenyl)xanthene (BHPX) was synthesized in 82% yield from xanthenone in a one‐pot, two‐step synthetic procedure. A new diacyl chloride monomer, 9,9‐bis[4‐(chloroformylphenoxy)phenyl]xanthene (BCPX), was synthesized in three steps from the nucleophilic fluorodisplacement of 4‐fluorobenzonitrile with the dipotassium bisphenolate of BHPX, followed by alkaline hydrolysis of the intermediate bis(ether nitrile), and then chlorination with thionyl chloride. Several novel aromatic polyamides containing ether and bulky xanthene groups with the inherent viscosities (0.72–0.98 dL/g) were prepared by the low temperature polycondensation of BCPX with various aromatic diamines in N,N‐dimethylacetamide (DMAc) solution containing pyridine (Py). All new polyamides were amorphous and readily soluble in various polar solvents such as DMAc, N,N‐dimethylformamide (DMF), N‐methyl‐2‐pyrrolidone (NMP) and Py. These polymers showed relatively high glass transition temperatures between 236 and 298°C, decomposition temperatures at 10% weight loss ranging from 490 to 535°C and 483 to 515°C in nitrogen and air, respectively, and char yields at 700°C in nitrogen higher than 50%. Transparent, flexible, and tough films of these polymers cast from DMAc solutions exhibited tensile strengths ranging from 82 to 106 MPa, elongations at break from 10% to 25%, and initial moduli from 2.0 to 2.8 GPa.     

Synthesis and properties of carbazole‐layered polymers

New aromatic ring‐layered polymers consisting of carbazole as a layered aromatic group and xanthene as a scaffold were designed and synthesized via the Sonogashira–Hagihara coupling reaction. Their optical and electrochemical behaviors were investigated in detail; the results showed that these polymers could be used as hole‐transporting materials. Polymers with nitrobenzene moieties at the polymer chain ends quenched the emission from the layered carbazoles to the nitrobenzene termini; thus, the polymers acted as the molecular wire that transferred photoexcited energy and/or electrons to the polymer termini. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4279–4288, 2009     

Fe3O4@Propylsilane@Histidine[HSO4‐] magnetic nanocatalysts: Synthesis,characterization and catalytic application for highly efficient synthesis of xanthene derivatives

The surface of Fe₃O₄ magnetic nanoparticles (MNPs) was modified by chloropropylsilane and histidine. The imidazole group of prepared Fe₃O₄@Propylsilane@Histidine MNPs converted to imidazolium hydrogen sulfate group and Fe₃O₄@Propylsilane@Histidine [HSO₄^‐] as a novel environmentally friendly ionic liquid/ magnetite nanoparticle was prepared, successfully. FT‐IR, XRD, SEM and TEM instruments was used to identifiy the histidine ionic liquids/magnetite nanoparticles (HILMNPs). The catalytic activity of synthesized HILMNPs was appraised for the synthesis of 9‐aryl‐1,8‐dioxooctahydroxanthene and spiro[indoline‐3,9′‐xanthene]trione derivatives. The activity of HILMNPs was much better than the other reported heterogeneous and homogeneous catalysts. Furthermore, the prepared catalyst could be separated from the reaction mixture and reused four times without any significant loss in its activity.