Ga(ClO_4)_3-catalyzed Reaction of 1,2-Diamines and α-Bromoketones:Synthesis of 2-Substituted Quinoxalines

Ga（ClO4）3-catalyzed reaction of 1,2-aryldiamines and α-bromoketones to afford 2-substituted quinoxalines in good yields is described.The reaction proceeded via grinding process with 10%（molar fraction） catalyst under solvent-free conditions at room temperature.For unsymmetrical o-phenylenediamines bearing electron-withdrawing groups,regio-selective quinoxalines were obtained.

Hydrothermal Syntheses and Crystal Structures of Two Metal-organic Complexes with 2,3-Pyridinedicarboxylic Acid and 2-Methyl-dipyrido[3,2-f:2',3'-h]quinoxaline Ligands

Two unusual one-dimensional（1-D） compounds,viz.[Co（Medpq）（QUI）·H2O]2n· 2.4nH2O 1 and [Cd（Medpq）（QUI）·H2O]n·nH2O 2,were synthesized by the combination of two different metallic salts and organic ligands,namely 2,3-pyridinedicarboxylic acid（H2QUI） and 2-methyldipyrido[3,2-f：2＇,3＇-h]quinoxaline（Medpq） ligand.The compounds were characterized by elemental analyses,TG,fluorescent emission and single-crystal X-ray diffraction analyses.

Synthesis and antibacterial activity of C-2(S)-substituted pleuromutilin derivatives

In order to probe the effect of C-2(S)-substituted groups in the antibacterial activity,a series of novel C-2(S)-substituted pleuromutilin analogues of SB-225586 were synthesized and evaluated for their in vitro antibacterial activity.The results of antibacterial activities indicated that C-2(S)-substituted pleuromutilin derivatives retained appreciable antibacterial activity,and the 2-fluorination compounds 6a and 6b are more potent than the corresponding 2-hydroxylation analogues 7a and 7b.

A simple and efficient synthesis of 2-substituted benzothiazoles catalyzed by H_2O_2/HCl

A simple and efficient procedure for the synthesis of substituted benzothiazoles through condensation of 2-aminothiophenol with aromatic aldehydes in the presence of H2O2/HCl system in ethanol at room temperature is described. The target compounds have been characterized by ^1H NMR, ^13C NMR, IR and MS. Short reaction time, easy and quick isolation of the products, and excellent yields are the main advantages of this procedure.

Hydrothermal Reaction, Structure and Magnetic Properties of a Binuclear Cobalt Complex with N-donor Ligand:2-Methyldipyrido[3,2-f:2ˊ3ˊ-h]quinoxaline

One complex [Co1.5（C6H5CHCHCOO）3（Medpq）]·H2O（C6H5CHCHCOO = cinnamic acid, Medpq = 2-methyldipyrido[3,2-f：2,3-h]quinoxaline） 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG, single-crystal X-ray diffraction and magnetic susceptibility measurements. Complex 1 crystallizes in the triclinic system, space group P1, with a = 10.224（5）, b = 14.572（5）, c = 15.139（5）A, α = 112.704（5）, β = 97.168（5）, γ = 109.749（5）, V = 1871.8（13） 3 and Z = 2（at 293（2） K）. In the crystal structure, the Co（1） ion is hexa-coordinated with six atoms from three different cinnamic acid ligands and the symmetric three different cinnamic acid ligands; the Co（2） center adopts a coordination environment with two nitrogen atoms from Medpq ligand and four oxygen atoms from two different cinnamic ligands, assuming a slightly distorted octahedral geometry, respectively. The negative value of the Weiss constant indicates antiferromagnetic exchange interactions between the Co ions.

Synthesis and anti-HBV activity of novel 5-substituted pyridin-2(1H)-one derivatives

Four novel 5-substituted pyridine-2(1H)-one derivatives were designed and synthesized by using addition-elimination reactions.The structures of these novelly synthesized compounds were verified by ~1H NMR,ESI-MS and single crystal X-ray diffraction.Furthermore,all four compounds(most notably compound 7a) were found to be highly efficient against hepatitis B virus (HBV) in cultured HepG2 2.2.15 cell,making them promising drug candidates for potential bioactive molecule against hepatitis B.

6-氟-4-羟基-3-氧代-3,4-二氢喹喔啉-1(2 H)-羧酸叔丁酯的合成、晶体结构及抗肿瘤活性研究

喹喔啉类化合物由于具有显著的生物活性而被广泛应用于医药、化工领域,特别是抗癌药物研发领域。本文通过四步反应法首次合成了6-氟-4-羟基-3-氧代-3,4-二氢喹喔啉-1(2 H)-羧酸叔丁酯,经溶液结晶法获得其单晶体。晶体学分析表明,该化合物属单斜晶系,空间群C2/c,晶胞常数a=1.28663(10)nm,b=2.25249(17)nm,c=1.01564(7)nm,Z=8,ρ_(c)=1.359 g·cm^(-3),R=0.0538,R_(w)=0.1406。在B3LYP/6-311+G(2d,p)模式下使用密度泛函理论(DFT)计算了该化合物的最佳结构,与X射线单晶衍射确定的晶体结构基本一致。抗肿瘤活性研究表明其有良好的抗肿瘤作用。此外,通过DFT计算了分子的静电势和前沿分子轨道。

Convenient Synthesis of Substituted Quinoxalines and 2H-Benzo[b][1,4]oxazines in Water

A facile and convenient synthesis method has been developed for substituted quinoxalines and 2H-benzo[b][1,4]oxazines from the reactions of a-bromoketones with benzene-1,2-diamine and 2-aminophenol, respectively, which were catalyzed by tetrabutylammonium bromide（TBAB） in aqueous basic media.

可见光诱导玫瑰红催化喹喔啉-2(1H)-酮的C3-H烷基化反应

建立了一种简单、实用的光诱导一锅法高选择性N-甲基喹喔啉酮类化合物和苯乙酮类化合物合成一系列3-烷基化喹唑啉-2(1H)-酮类化合物的方法。该方法在室温条件下,以玫瑰红作为光催化剂,在18 W 460 nm的蓝色LED下照射8 h,通过直接C3-H活化的方案,较好收率获得一系列相应的3-烷基化喹喔啉-2(1H)-酮类化合物,最高产率可达到76%。反应体系具有经济实用性和底物适用范围广的特点,为3-烷基化喹喔啉-2(1H)-酮类化合物类化合物的合成提供了一种简便经济的方法。

Synthesis of 2-Phenyl-10-substituted Hymenialdisine Derivatives

A series of novel 2-phenyl-10-substituted hymenialdisine derivatives was synthesized via the micro-wave-assisted Suzuki-Miyaura cross-coupling reactions of the 2-phenyl derivative of hymenialdisine and boronic acid, which enabled the successful introduction of electron-donating and electron-withdrawing groups to the 2-phenyl- hymenialdisine derivatives in good yields.

Syntheses of 2- or 6-Substituted Chromones and Chromone Ring-opening Reaction in Polyphosphoric Acid

In an attempt to find new antitumor agents,a novel class of chromone compounds with a benzimidazole or a benzoxazole ring in positions 2 or 6 were synthesized via condensation in polyphosphoric acid(PPA) by using chromone acids as the starting materials. During the preparation process,it was found that PPA could cleave the chromone ring to produce a ring-opening compound(6). The molar ratio of the chromone compound(5) to the ring-opening compound(6) varied with the change of reaction temperature and time. Based on MTT protocol,the antitumor activity of each of the compounds obtained was evaluated against three human cancer cell lines: KB(oral epidermal),A2780(ovary) and Bel7402(liver). The IC_ 50 varied from 54.7 μmol/L to more than 180 μmol/L.

SYNTHESIS OF 4-SUBSTITUTED (OR 4-SPIRO) 3-OXABICYCLO[3.1.0]HEXAN-2-ONE

Cyclopropanedicarboxylic anhydride can be converted to 4-substituted (or 4-spiro-)3-oxabicyclo[3.1.0]hexan-2-one by addition of Grignard (or α,ω-di-Crignard) reagents in ether or tetrahydrofuran solution.

Synthesis of quinoxaline derivatives catalyzed by PEG-400

Polyethylene glycol(PEG) was found to be an effective catalyst for the condensation of 1,2-diamines with 1,2-dicarbonyl compounds to afford the corresponding quinoxaline derivatives in excellent yields under mild reaction conditions.

Aspects on the Mechanism of the 1-Phenyl-1<i>H</i>-pyrazolo[3,4-<i>b</i>]quinoxaline Formation

Condensation of D-glucose, o-phenylenediamine and N,N-benzylphenylhydrazine hydrochloride (NNBPHH) in a one-pot reaction, or condensation of 2-(D-arabino-tetritol-1-yl) quinoxaline and NNBPHH, gave 3-(D-erythro-glycerol-1- yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure of the latter was determined by 1H NMR spectroscopy and by synthesis using phenylhydrazine hydrochloride instead of NNBPHH. Condensation of D-glucose and 4,5-dichloro-o-phenylenediamine gave 6,7-dichloro-2-(D-arabino-tetritol-1-yl)quinoxaline, which upon condensation with NNBPHH gave the corresponding 6,7-dichloro-3-(D-erythro-glycerol-1-yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure and mechanism of formation of these compounds are discussed.

An Efficient Approach to 6, 7-Disubstituted-1H-quinoxalin-2-ones

A novel approach to the synthesis of 6, 7-disubstituted-1H-quinoxalin-2-ones is described.The title compounds were regioselectively prepared by starting from substituted phenylamines andchloroacetyl chloride through the efficient sequence of acylation, nitration, reduction, intramolecular alkylation, and oxidation.

Synthesis and Molecular Structure of Acetic Acid-3,5-diacetoxy-2-acetoxymethyl-6-(4-quinoxalin-2-yl-phenoxy)-tetrahydro-pyran-4-yl-ester

The title compound, acetic acid-3,5-diacetoxy-2-acetoxymethyl-6-（4-quinoxalin- 2-yl-phenoxy）-tetrahydro-pyran-4-yl-ester 8 （C28H28N2O10, Mr = 552.54）, has been synthesized and its crystal structure was determined by X-ray diffraction analysis. It crystallizes in monoclinic, space group P21, a = 10.060（8）, b = 5.648（4）, c = 24.11（2）A, β = 91.078（10）°, Z = 2, V= 1369.9（19）A^3, Dc = 1.339 g/cm^3,μ（MoKa） = 1.03 cm^-1, F（000） = 580.00, T =. 193.1 Kx-9 θmax = 25.03, （△/σ）max = 0.0000, Flack = -0.0（24）, the final R = 0.0680 and wR = 0.140 （w = 1/[0.0016Fo^2 ＋ 1.00000（Fo^2）]/（4Fo^2）） for 3126 observed reflections （1 〉 20（/））. The pyranoid ring adopts chair conformation in the sugar moiety, and all of the acetyl groups are in the e bond of the pyranoid ring, so the sugar moiety is very stable.

光诱导过硫酸铵催化喹喔啉-2(1H)-酮的C3芳基化反应

建立了一种光诱导一锅法高选择性促进喹唑啉-2(1H)-酮类化合物和苯肼化合物合成一系列3-芳基化喹唑啉-2(1H)-酮类化合物的方法。以过硫酸铵作为光催化剂,在18 W的蓝色发光二极管下照射18 h,通过直接C3-H活化,得到各种相应的3-取代喹喔啉-2(1H)-酮类化合物,收率达86%。方法具有反应条件温和、经济实用和底物适用范围广的特点。

喹喔啉-2(1H)-酮的非均相光催化C-H反应研究进展

喹喔啉-2(1H)-酮类化合物在药物和材料方面有广泛的应用,通过非均相光催化反应直接进行C-H功能化对于绿色化学发展至关重要。本综述对喹喔啉-2(1H)-酮非均相光催化反应方法进行系统总结,按照催化剂的类型分类为石墨相氮化碳、共价有机框架(COF)、离子交换树脂和微球等五部分,分别讨论喹喔啉-2(1H)-酮的不同反应类型反应条件和反应底物等。通过总结已有反应类型,对存在的不足和发展方向提出建议,如非均相光催化反应构建C-B/Si/P/RF/X/Se键,丰富非均相光催化剂类型,开发不对称合成等领域等,旨在使喹喔啉-2(1H)-酮的绿色和可持续的非均相光反应方法广泛应用于材料化学和药学。

采用高效液相色谱-串联质谱法检测鲫鱼组织3-甲基喹噁啉-2-羧酸残留量

将待测鱼肉和鱼皮匀浆样品经碱水解、液-液萃取后,采用HPLC-TMS方法对其中的3-甲基喹噁啉-2-羧酸(MQCA)残留量进行了检测。结果,此方法的最低检测限为1.16μg/kg,市售鲫鱼样品中MQCA的含量低于检测限。结果表明,HPLC-TMC灵敏,易操作,能满足鱼组织内MQCA残留量检测的要求。