植物酶催化光度法测定痕量甲胺磷的初步研究

对植物酶催化酯类检测痕量有机磷农药残留量的方法进行了初步研究。在乙酸-乙酸钠的缓冲体系中,应用植物淀粉酶促进α-乙酸萘酯分解生成α-萘酚,甲胺磷农药抑制淀粉酶的活性,淀粉酶的活性随甲胺磷浓度增加而降低,α-乙酸萘酯分解生成的α-萘酚量也减少,以FeCl3指示反应,反应生成一种紫色络合物,利用该反应对甲胺磷进行定量测定。确定了反应的最佳条件,方法已应用于蔬菜表面甲胺磷残留量的分析。     

Direct photooxidation and xanthene-sensitized oxidation of naphthols: quantum yields and mechanism

The photoinduced oxidation of 1-naphthol to 1,4-naphthoquinone and of 5-hydroxy-1-naphthol to 5-hydroxy-1,4-naphthoquinone was studied by steady-state and time-resolved techniques. The direct photooxidation of naphthols in methanol or water takes place by reaction of the naphoxyl radical ((?)ONaph) with the superoxide ion radical (O(2)(?-)), the latter of which results from the reaction of the solvated electron with oxygen after photoionization. The sensitized oxidation takes place by energy transfer from the xanthene triplet state to oxygen. From the two oxygen atoms, which are consumed, one is incorporated into the naphthol molecule giving naphthoquinone and the second gives rise to water. The effects of eosin, erythrosin, and rose bengal in aqueous solution, pH, and the oxygen and naphthol concentrations were studied. The quantum yield of the photosensitized transformation was determined, which increases with the naphthol concentration and is largest at pH > 10. The quantum yield of oxygen uptake is similar. The pathway involving singlet molecular oxygen is suggested to operate for the three sensitizers. The alternative pathway via electron transfer from the naphthol to the xanthene triplet state and subsequent reaction of (?)ONaph with O(2)(?-), the latter of which is formed by scavenging of the xanthene radical anion by oxygen, does also contribute.     

Synthesis,anti-leishmanial screening,molecular docking,and ADME study of 1-amidoalkyl 2-naphthol derivatives catalyzed by amino acid ionic liquid

Research on Chemical Intermediates - A series of amidoalkyl naphthol (AAN) derivatives have been synthesized by a one-pot multicomponent reaction of β naphthol, amide, and aromatic aldehydes...     

Sulfonyl chlorination of sulfonate-containing naphthol azo compounds

Chlorosulfonyl-containing naphthol azo compounds were prepared by reaction of the corresponding sulfonate-containing naphthol azo dyes with thionyl chloride in the presence of a catalytic quantity of N,N-dimethylformamide and various solvents. The yields and reaction selectivity of chlorosulfonyl-containing naphthol azo compounds were discussed according to the properties of solvents. It was demonstrated that high chemical selectivity and high yield were achieved by using benzene, toluene or thionyl chloride as solvent. Additionally, on account of unstable properties of sulfonyl chloride compounds in MS and ¹H-NMR analyses, a new analytical method using stable sulfonamide is put forward to verify the chemical structures of the corresponding sulfonyl chloride compounds indirectly. __________ Translated from Journal of Dalian University of Technology, 2008, 48(1): 26–32     

Enantiopure α-imino glyoxylate: a versatile substrate for the spontaneous asymmetric synthesis of unnatural hydroxyaryl glycinates

A novel synthesis of useful enantiomerically pure arylglycinates via spontaneous reaction between phenol or naphthol derivatives and enantiopure α-imino glyoxylate in the absence of an acid catalyst is reported. A library of enantiopure substituted phenol or naphthol glycinates was obtained in good yields and high diastereoselectivities. Diastereoisomerically pure aryl glycinates were obtained by direct flash chromatography separation of the crude reaction mixture. The free OH moiety of the phenols or naphthols contributed to the activation of the imino group to form an intermolecular hydrogen bond and promoted the reaction in the absence of an acid catalyst, as shown in the transition state reported. The diastereoselectivity is due to thermodynamic control in the addition step.     

Convenient Method for Synthesis of Substituted 2‐Amino‐2‐chromenes

Some substituted 2‐amino‐2‐chromenes were synthesized by the reaction of arylidenemalononitriles with 1‐naphthol or 2‐naphthol in the presence of sodium hydroxide as catalyst under solvent‐free condition.     

An Efficient Synthesis of 5,6‐Dimethoxy 1‐ and 2‐Naphthols via Teuber Reaction

Based on the oxidation of 1,5‐naphthalenediol ( 4 ) and 6‐bromo‐2‐naphthol ( 9 ) via Teuber reaction, an efficient synthesis of 5,6‐dimethoxy‐1‐naphthol ( 1 ) and 5,6‐dimethoxy‐2‐naphthol ( 2 ) was achieved with high overall yield (16% for 1 and 25% for 2 ). The key steps of the synthetic strategy involved the oxidation of naphthols ( 4 and 9 ) to the corresponding naphthoquinones ( 5 and 10 ) and the conversion of 5,6‐dimethoxy‐2‐naphthaldehyde to 5,6‐dimethoxy‐2‐naphthol formate through Baeyer‐Villiger oxidation‐rearrangement.     

Triton B catalyzed three‐component,one‐pot synthesis of 2‐amino‐2‐chromenes at ambient temperature

A one‐pot, three‐component synthesis of 2‐amino‐2‐chromenes is described at ambient temperature by the reaction of an aldehyde and malononitrile or ethyl cyanoacetate with α‐naphthol or β‐naphthol in ethanol in presence of a catalytic amount of Triton B. J. Heterocyclic Chem., (2011).     

Flow-injection catalytic spectrophotometric determination of nitrite using the redox reaction between naphthol green B and potassium bromate

A flow injection catalytic spectrophotometric method is proposed for the determination of nitrite based on its catalytic effect on the redox reaction between naphthol green B and potassium bromate in phosphoric acid medium. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of naphthol green B at the maximum absorption wavelength of 722 nm. The detection limit is 0.5 ng cm(-3) in a sample volume of 90 mm(3). Up to 50 samples can be analyzed per hour with a relative precision of ca. 2%. The method is free from most interferences, especially from large amounts of nitrate. The procedure was successfully applied to the determination of trace nitrite in natural waters.     

Detection of the reversibility of an excited-state reaction by phase-modulation fluorometry

We used phase and modulation fluorometry to investigate the excited-state proton transfer from 2-naphthol. Phase-sensitive detection of fluorescence allows determination of the phase angles of the two-excited species, naphthol and naphtholate. If the steady-state spectra of the individual species are known and are not identical, then this general procedure yields the phase angles irrespective of the extent of the spectral overlap. The phase difference (Δφ) between the naphthol and naphtholate emission is given by tan Δφ = ω/(Γ_R + k₂ where ω is the circular modulation frequency, Γ_R the decay rate of naphtholate fluorescence and k₂ the rate of the reverse reaction. Hence, Δφ reflects both the decay rate of the reaction product and the rate of the reverse action. This back reaction was also detected by comparison of phase shift (φ) and demodulation (m) values for the initially excited state. Specifically, the reverse reaction results in a double exponential decay of naphthol fluorescence, which is revealed by m/cosφ < 1. The concepts described herein are generally applicable to determination of the reversibility of excited-state reactions.     

FeCl3-Catalyzed Condensation of 2-Naphthol and Aldehydes under Solvent-Free Reaction Conditions: An Efficient and Green Alternative for the Synthesis of 14-Aryl(Alkyl)-14-H-dibenzo[a, j]xanthenes

An iron‐catalyzed condensation of 2‐naphthol with aldehydes has been described. In the presence of a catalytic amount of iron(III) chloride (5 mol%), the condensation reaction of 2‐naphthol and aldehydes underwent smoothly to generate the corresponding products in good to excellent yields under base‐, acid‐, ligand‐, additive‐, and solvent‐free reaction conditions.     

PEG-400为绿色反应介质无催化一锅法合成2-氨基-3-氰基-4-芳基-4H-苯并色烯衍生物

PEG-400为绿色反应介质下无催化萘酚、丙二腈及芳香醛三组分“一锅法”高产率地得到了苯并色烯衍生物. 该反应具有产率高、污染少、操作简单、环境友好等优点, 产物的结构通过红外光谱和核磁共振谱进行了表征.     

Multi‐wall carbon nanotube supported Co (II) Schiff base complex: an efficient and highly reusable catalyst for synthesis of 1‐amidoalkyl‐2‐naphthol and tetrahydrobenzo[b]pyran derivatives

An immobilized Co (II) Schiff base complex supported on multi‐wall carbon nanotubes was synthesized and characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy , thermogravimetric analysis and inductively coupled plasma mass spectrometry. It was shown that the supported complex is a facile, eco‐friendly, recyclable, reusable and green catalyst for three‐component condensation of 2‐naphthol and acetamide with various aldehydes for the synthesis of 1‐amidoalkyl‐2‐naphthol derivatives under solvent‐free conditions. Also, in a further study, the catalytic application was studied in the synthesis of tetrahydrobenzo[b ]pyran derivatives via the condensation reaction of malononitrile and dimedone with several aromatic aldehydes. The procedures suggested here for the synthesis of 1‐amidoalkyl‐2‐naphthol and tetrahydrobenzo[b ]pyran derivatives offer several advantages, such as stability, recyclability and eco‐friendliness of the catalyst, simple experimental conditions, short reaction times, high to excellent yields and easy work‐up.     

金属卟啉催化氧化萘酚 Ⅰ.2-羟基-1,4-萘醌的制备

羟基萘醌;金属卟啉催化氧化萘酚 Ⅰ.2-羟基-1;4-萘醌的制备     

一类新型手性烷基氨基酚类配体的合成

利用Mannich反应, 高对映选择性地以中等产率合成了三个新型烷基氨基苯酚类配体及6个具有C₂对称轴的烷基氨基萘酚类配体. 合成的9个新化合物的结构经元素分析, IR, ¹H NMR, ¹³C NMR和MS等确定, 其中两个化合物4和7通过X射线单晶衍射确定了新生成的手性中心的绝对构型.     

Decolorization of Naphthol Blue Black using the Horseradish Peroxidase

This study evaluates the potential of the enzyme horseradish peroxidase in the decolorization of one common industrial azo dye, naphthol blue black. Studies are carried out to understand the process parameters such as pH, temperature and reaction time. The enzymatic decolorization of the dye was examined by UV-Vis spectrophotometer and LC-MS measurements. Temperature and pH conditions were optimized for obtaining high azo-dye decolorization. Azo-dye removal at a pH range 4-6 was found to be the highest for all temperatures. After 5 minutes of treatment, the color removal of dye was ca. 80-90%. The LC-MS and spectrophotometric analyses indicated that the decolorization of the azo dye with enzyme was due to the reduction of the azo bonds. This study verifies the viability of the use of the horseradish peroxidase in the decolorization of naphthol blue black.     

重氮萘酮在环醚中热解反应研究

三种带有不同取代基的重氮萘酮(la～1c)在THF和二氧六环中加热分解给出不同的产物。1-重氮-4-萘酮(1a)的热解产物主要是重氮萘酮热解后产生的烯酮卡宾(2a)与环醚开环后形成的聚合物;3-甲基-1-重氮-4-萘酮(1b)的热解产物比较复杂,除冠醚类产物之外,还有烯酮卡宾对四氢呋喃和二氧六环的C-H键的插入反应产物、螺环化合物、2-甲基萘酚以及难以分离的聚合物;3-硝基-1-重氮-4-萘酮(1c)的热解产物主要是聚合物,此外还有少量C－H键的插入反应产物和2-硝基萘酚。对重氮萘酮热解反应的机理作了讨论。     

Optimizing the kinetics of persulfate‐mediated oxidative coupling of phenols to 4‐aminoantipyrine

The kinetics of the persulfate oxidation of phenol, p‐ethylphenol, and 1‐naphthol in the presence of 4‐aminoantipyrine under basic condition was studied. Parallel oxidation of 4‐aminoantipyrine was observed to influence the rate law in a very complicatedway. The rate law was simplified by limiting the concentration of the phenol, and optimizing the excess persulfate and the 4‐aminoantipyrine. Under such condition, the rate law is independent of the concentration of 4‐aminoantipyrine. The order of reaction was found to be one with respect to the concentrations of a phenol or persulfate. The second order rate constant was highest for 1‐naphthol followed by phenol and p‐ethylphenol in that order. © 2001 John Wiley & Sons, Inc. Int J chem Kinet 33: 600–604, 2001     

Zeolitic imidazolate framework 8 (ZIF‐8) reinforced macroporous resin D101 for selective solid‐phase extraction of 1‐naphthol and 2‐naphthol from phenol compounds

Macroporous resin has been attracting intensive attention due to its critical role in separation and purification of natural products. Herein, a zeolitic imidazolate framework 8 reinforced macroporous resin D101 was prepared via a room temperature growth method and used for dispersive SPE of 1‐naphthol and 2‐naphthol. The parameters affecting the adsorption and desorption efficiency such as the sample pH, adsorbent amount, extraction time, desorption solvent, and desorption time were investigated. The as‐prepared adsorbent showed selectivity for 1‐naphthol and 2‐naphthol compared to other phenols. Under the optimum dispersive SPE conditions, the detection of 1‐naphthol and 2‐naphthol coupled with a CZE method was conducted and the LODs for 1‐naphthol and 2‐naphthol were 1.37 and 1.43 ng/mL, respectively. Moreover, the results of urine sample analysis showed the spiked recoveries to be in the range of 96.2–106.9%. This study indicated that D101@ZIF‐8 (where ZIF is zeolitic imidazolate framework) is a promising selective adsorbent for the analysis of 1‐naphthol and 2‐naphthol in urine samples.     

碱性离子液体催化合成取代萘并吡喃衍生物

离子液体具有强极性、不挥发、化学稳定性好等特点,其极性和亲水/亲脂性可通过改变烷基碳链的长短和阴、阳离子的种类来进行调节,对其结构进行化学修饰,可以得到具有特定功能的离子液体[1-3],因此被誉为绿色溶剂和可设计的溶剂[2]。许多萘并吡喃衍生物都具有重要的生物活性和药