微波作用下2-烃基-4-喹啉酮的简便合成法

在微波作用下5-(甲硫亚烃基)丙二酸亚异丙酯可与芳胺发生加成消除反应,首先生成5-(芳胺基亚烃基)丙二酸亚异丙酯,继而进一步闭环,提供了2-烃基-4-喹啉酮的快速合成法。     

Regioselective Synthesis ofPyrano[3,2-f]quinolin-2(7H)-onesand Furo[3,2-f]quinolin-2-ones

Summary.  A simple and efficient synthesis of the hitherto unreported ring systems pyrano[3,2-f]quinolin-2(7H)-one and furo[3,2-f]quinolin-2-one was accomplished via a thermal [3,3]-sigmatropic rearrangement. Received March 7, 2000. Accepted May 4, 2000     

分散固相萃取-超高效液相色谱-串联质谱法同时检测火锅食材中11种喹诺酮类药物

建立了一种固相分散萃取-超高效液相色谱-串联质谱(QuEChERS-UPLC-MS/MS)同时检测火锅食材中11种喹诺酮类药物的方法。样品用5%甲酸乙腈溶液提取后加入盐析剂分层,提取液中加入C18和PSA填料进行基质分散固相净化,浓缩后经Poroshell 120 EC-C18柱分离,用电喷雾离子源正离子多反应监测(MRM)模式串联质谱进行检测。11种药物在1.0~100.0 μg/kg范围内具有较好的线性关系,相关系数均大于0.998。该方法检出限(LOD)为1.8~3.1 μg/kg,定量限(LOQ)为6.0~10.3 μg/kg。11种药物的回收率为70.1%~100.3%,相对标准偏差(RSD)为2.42%~10.88%。该方法简便快速、灵敏度高、准确度好、使用范围广,可作为火锅食材中11种喹诺酮类药物残留的确证方法。     

Ni(II) Ternary Complex Based on Antimicrobial Drug Enoxacin: Synthesis and Biological Properties

First Ni(II) ternary complex using the quinolone antibacterial agent enoxacin (HEn) as ligand and 1,10‐phenanthroline as co‐ligand has been synthesized and characterized. It is a mononuclear structure, in which enoxacin acts as a bidentate ligand bound to the metal through the ketone oxygen and a carboxylate oxygen atom. The complex exhibited good binding propensity to human and bovine serum albumin proteins having relatively high binding constants (6.40×10⁴ and 7.12×10⁴, respectively). The investigation of the interaction of the complex with calf‐thymus (CT) DNA has been performed with UV and circular dichroism (CD) spectroscopies, indicating that they bind to CT DNA probably by the intercalative binding mode. The binding constant (K_b) of the complex with CT DNA calculated with UV is 2.03×10⁵, which is higher than that of free enoxacin drug (2.09×10⁴) and even higher than that of typical intercalation indicator (1.23×10⁵) of ethidium bromide (EB). Fluorescence competitive studies with EB have revealed that the complex exhibited the ability to displace the DNA‐bound EB using the intercalative binding site. In addition, the antimicrobial activity showed that the complex exhibited a little bit good inhibition (MIC=1.843 (g·mL^?1) against B. subtilis than free HEn.     

固相萃取-高效液相色谱-荧光检测土壤中喹诺酮类抗生素

建立了固相萃取-高效液相色谱-荧光(HPLC-FLD)检测土壤中4种喹诺酮类抗生素的分析方法.样品采用50% Mg(NO_3)_2-10% NH_3 · H_2O(96∶ 4,V/V)超声提取,过HLB柱富集净化,再用乙腈-0.067 mol/L H_3PO_4溶液洗脱.采用高效液相色谱-荧光检测器,以乙腈-0.067 mol/L H_3PO_4(用三乙胺调节至pH 2.5)为流动相,于激发波长280 nm、发射波长450 nm处进行检测.土壤样品中4种喹诺酮类抗生素的加标回收率在60.4%～99.3%之间,检出限为0.58～1.0 μg/kg.对蔬菜基地土壤样品分析结果表明,本方法能够满足实际样品的分析要求,4种喹诺酮类抗生素均被检出,土壤中抗生素污染问题值得关注.     

Ytterbium-catalyzed formal [4+2] cycloaddition: Synthesis of chalcogen-quinolines 3-unsubstituted

A regioselective ytterbium-catalyzed annulation reaction between ethylglyoxalate, anilines and silyl-alkynes bearing selenyl- and telluryl-moieties for the formation of poly-substituted quinolones is described. A series of examples formed under mild conditions are presented, including a scaled-up reaction and a study on catalyst recyclability.     

Regioselective preparation and NMR spectroscopy study of 2-chloro-4-ethoxy-quinoline for the synthesis of 2-((3-aminopropyl)amino)quinolin-4(1H)-one

Herein, we describe the C4-ethoxylation of 2,4-dichloroquinoline to prepare 2-chloro-4-ethoxy-quinoline ( 3 ), which is a prominent intermediate used for the synthesis of 2-substituted quinolones. To achieve this goal, we studied different conditions for the reaction between 2,4-dichloroquinoline and sodium ethoxide. We discovered that the use of 18-crown-6 ether as an additive and dimethylformamide as the reaction solvent allowed us to obtain the desired product 3 in very good yield and selectivity. In addition, a definitive distinction between the C2 and C4 ethoxylation products was achieved using ¹H─¹⁵N heteronuclear multiple bond correlation. Compound 3 is an intermediate used for the synthesis of 2-((3-aminopropyl)amino)quinolin-4(1H)-one, which displays peculiar behavior during ¹H nuclear magnetic resonance analysis, such as the broadening of the H8 singlet and unexpected deuteration at the C8-position. Effort has been dedicated to understand these findings.     

Oxidation of quinolones with peracids (an in situ EPR study)

4‐Oxoquinoline derivatives (quinolones) represent heterocyclic compounds with a variety of biological activities, along with interesting chemical reactivity. The quinolone derivatives possessing secondary amino hydrogen at the nitrogen of the enaminone system are oxidized with 3‐chloroperbenzoic acid to nitroxide radicals in the primary step while maintaining their 4‐pyridone ring. Otherwise, N‐methyl substituted quinolones also form nitroxide radicals coupled with the opening of the 4‐pyridone ring in a gradual oxidation of the methyl group via the nitrone–nitroxide spin‐adduct cycle. This was confirmed in an analogous oxidation using N,N‐dimethylaniline as a model compound. N‐Ethyl quinolones in contrast to its N‐methyl analog form only one nitroxide radical without a further degradation. Copyright © 2013 John Wiley & Sons, Ltd.     

Stabilization of [2.2]paracyclophane anion as a result of transannular interaction

The review surveys methods for the construction of bi- and polycyclic nitrogen-, oxygen-, and sulfur-containing heterocycles based on reactions of 2-halobenzoyl chlorides with dinucleophiles.     

超快速液相–质谱法同时测定液体奶和奶粉中磺胺和喹诺酮类药物残留

建立超快速液相–质谱联用法测定乳制品中磺胺和喹诺酮类药物残留的方法。试样加入乙腈沉淀蛋白,用0.22μm滤膜过滤,经EndeavorsilTMC18柱分离,选用乙腈–0.1%甲酸为流动相。在0.05~100.00μg/L范围内,17种兽药的质量浓度均与色谱峰面积均呈良好的线性,相关系数(r2)为0.990 6~0.999 8,方法检出限为0.05~0.10μg/kg,加标回收率为75.88%~116.00%,测定结果的相对标准偏差为1.5%~13%(n=5)。该方法快速、灵敏,可以满足对乳制品中多种兽药残留的快速检测要求。