Silica supported perchloric acid(HClO_4-SiO_2):A mild,reusable and highly efficient heterogeneous catalyst for the synthesis of amidoalkyl naphthols

An efficient and direct procedure has been developed for the preparation of amidoalkyl naphthols by a one-pot condensation of aryl aldehydes, 2-naphthol and urea or amides, in the presence of HClO4-SiO2 as a heterogeneous catalyst. The reactions were carried out under reflux and solvent-free conditions. The present methodology offers several advantages such as excellent yields, simple procedure, easy work-up and ecofriendly reaction condition. The catalyst is easily prepared, stable, reusable and efficient under the reaction conditions.

Kinetic spectrophotometric method for the determination of cerium(IV) with naphthol green B

A simple and sensitive spectrophotometric method was described for the determination of cerium（IV） based on its catalytic effect on the oxidation of naphthol green B by potassium periodate in the medium of sulfuric acid. The influences of acidity, concentration of reactants, reaction time, reaction temperature, and foreign ions were discussed, and the optimum reaction conditions were established. The reaction was monitored spectrophotometrieally by measuring the decrease in absorbance of naphthol green B at 710 nm after a fixed time （8 min）. The proposed method allowed the determination of cerium（IV） in the range of 0.08-2.4 μg·mL^-1 with good precision and accuracy, and the detection limit was 0.012 μg·mL^-1. The method was applied successfully for the determination of trace cerium in hair samples without previous separation. Recovery experiments were also performed, and the recovery was between 95.7%-111.0%.

Biodegradation of 2-naphthol and its metabolites by coupling Aspergillus niger with Bacillus subtilis

To explore biodegradation of 2-naphthol and its metabolites accumulated in wastewater treatment,a series of bio-degradation experiments were conducted.Two main metabolites of 2-naphthol,1,2-naphthalene-diol and 1,2-naphthoquinone,were identified by high-performance liquid chromatography with standards.Combining fungus Aspergillus niger with bacterium Bacillus subtilis in the treatment enhanced 2-naphthol degradation efficiency,lowered the accumulation of the two toxic metabolites.There were two main phases during the degradation process by the kinetic analysis：2-naphthol was first partly degraded by the fungus,producing labile and easily accumulated metabolites,and then the metabolites were mainly degraded by the bacterium,attested by the degradation processes of 1,2-naphthalene-diol and 1,2-naphthoquinone as sole source of carbon and energy.Sodium succinate,as a co-metabolic substrate,was the most suitable compound for the continuous degradation.The optimum concentration of 2-naphthol was 50 mg/L.The overall 2-naphthol degradation rate was 92%,and the COD Cr removal rate was 80% on day 10.These results indicated that high degradation rate of 2-naphthol should not be considered as the sole desirable criterion for the bioremediation of 2-naphtholcontaminated soils/wastewater.

Synthesis of 1,1'-binaphthyl-2,2'-diamine from 2-naphthol under atmospheric pressure

A practical protocol to obtain 1,1′-binaphthyl-2,2′-diamine was developed from 2-naphthol and 2-naphthylhydrazine under mild conditions： solvent-free, 125-130 ℃, atmospheric pressure. The convenient procedure makes the process amenable for large-scale synthesis of the versatile compound.

Degradation of α-Naphthol by Plasma in Aqueous Solution

Degradation of α-naphthol induced by plasma in aqueous solution was investigated in different initial concentration with contact glow discharge electrolysis(CGDE). The results showed that the degradation of α-naphthol obeyed the first-rate law. Some of predominant products were analyzed by a high performance liquid chromatography (HPLC). A path of α-naphthol disappearance caused by plasma was proposed according to the detected intermediate products.

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment, but sorption mechanism is still not fully understood. In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction. Toward this end, cuticular materials were isolated from the fruits of tomato by chemical method. The tomato cuticle sheet consisted of waxes （6.5 wt%）, cuticular monomer （69.5 wt%）, and polysaccharide （24.0 wt%）. Isotherms of 1-naphthol to the cuticular fractions were nonlinear （N value （0.82 - 0.90）） at the whole tested concentration ranges. The K∞/Kow ratios for bulk cuticle （TC1）, dewaxed cuticle （TC2）, cutin （TC4）, and desugared cuticle （TC5） were larger than unity, suggested that tomato bulk cuticle and cutin are much powerful sorption medium. Sorption capability of cutin （TC4） was 2.4 times higher than the nonsaponifiable fraction （TC3）. The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar （H-bonding） interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material. There was a linear negative trend between K∞ values and the amount of polysaccharides or fraction＇s polarities （（N＋O）/C）; while a linear positive relationship between K∞ values and the content ofcutin monomer （linear R^2 = 0.993） was observed for present in the cuticular fractions. Predominant sorbent of the hydrophobic organic compounds （HOCs） in the plant cuticular fraction was the cutin monomer, contributing to 91.7% of the total sorption of tomato bulk cuticle.

Effects of the surface chemistry of macroreticular adsorbents on the adsorption of 1-naphthol/1-naphthylamine mixtures from water

The adsorption behaviors of 1-naphthol, 1-naphthylamine and l-naphthol/l-naphthylamine mixtures in water over two macroreticular adsorbents were investigated in single or binary batch systems at 293 K, 303 K and 313 K respectively. All the adsorption isotherms in the studied systems can be adequately fitted by Langmuir model. In the case of aminated macroreticular adsorbent NDA103, 1-naphthol is adsorbed to a larger extent than 1-naphthylamine; while, the opposite trend is found for nonpolar macroreticular adsorbent NDA100. It is noteworthy that at higher temperature（303 K and 313 K）, the total uptake amounts of 1-naphthol and 1-naphthylamine in all binary-component systems are obvious larger than the pure uptake amounts in single-component systems, which is presumably due to the cooperative effect primarily arisen from the hydrogen-bonding interaction between the loaded 1-naphthol and 1-naphthylamine molecules. The simultaneous adsorption systems were confirmed to be helpful to the selective adsorption towards 1-naphthol according to the larger selective index.

ADSORPTION OF LATERALLY INTERACTING 1-NAPHTHOL/1-NAPHTHYL-AMINE MIXTURES ON NONPOLAR SURFACES FROM AQUEOUS SOLUTIONS

The binary adsorption behavior of 1-naphthol/1-naphthylamine mixtures in water on nonpolar adsorbent Amberlite XAD4 was investigated at 293 K, 303 K and 313 K, respectively. The experimental uptakes of 1-naphthol and 1-naphthylamine in all binary-component systems of different molar ratios were obviously higher than the corresponding uptakes predicted by the extended Langmuir model, assuming no interaction between the adsorbed molecules of the two components. This phenomenon was attributed to the cooperative adsorption effect arising from the hydrogen bonding interaction between 1-naphthol and 1-naphthylamine molecules. A modified extended Langmuir model was proposed to describe the binary adsorption behavior by means of introducing a fitting parameter related with the cooperative adsorption effect of the adsorbates.

Preparation of Enantiomerically Pure 1,1'-Bi-2-naphthols from 85% Cinchonine and 1,1'-Bi-2-naphtholboric Anhydride

A possibility of preparation of enantiomerically pure 1,1' bi 2 naphthols using an impure cinchonine has been examined. The solid and the mother liquor formed from the reaction of 1,1' bi 2 naphtholboric anhydride and 85 % cinchonine in toluene could give optically pure (S) ( ) and (R) (+) 1,1' bi 2 naphthol after acidification and kinetic crystallization, the overall yields were 40 % and 28 %, respectively.

Catalytic Oxidative Conversion from Naphthol to 2-Hydroxy-1, 4-naphthoquinone over Iron Porphyrin Catalysts by Molecular Oxygen in an Alkaline 2-Propanol Solution

In an alkaline 2-propanol solution with 5,10,15,20-tetra(4-methoxyl phenyl) porphyrin iron chloride(TOMPPFeCl) as a catalyst and oxygen as a cheap green oxidant, 2-naphthol was conversed to 2-hydroxy-\{1,4-naphthoquinone(HNQ)\} with a yield of 62.17% and a selectivity of 100%, and the conversion number of TMOPPFeCl catalyst was 8.32/min. The catalytic oxidation products were characterized by means of UV-Vis, IR, GC-MS, ~ 1H NMR and melting point determination. In this catalytic oxidation, the catalytic activity of TMOPPFeCl was researched in detail and the reacting conditions were optimized. A possible reaction mechanism is summarized based on in situ EPR determination.

A New Amperometric Glucose Biosensor with Naphthol Green B as Mediator

Naphthol green B was used, for the first time, as a new mediator in an amperometric glucose biosensor. It is a good mediator, promoting electron transfer from glucose oxidase to graphite electrode. The biosensor shows high sensitivity to glucose at low potential with response time of 30 seconds. The linear range is from 1.5 to 18 靘ol/L glucose with detection limit of 0.5 靘ol/L glucose.

Studies on the Conformation of Poly (1-naphthol) Assembled by Horseradish Peroxidase in Aqueous Micelle

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BEHAVIOUR OF α-NITROSO-β-NAPHTHOL IN HEMATITE FLOTATION

Based on theoretical calculation of electronegativity of groups of flotation reagent and method of infrared adsorption spectroscopy,the collection and adsorption of α-nitroso-β- naphthol in hematite flotation have been studied.The chemical adsorption seems to be predominant owing to formation of pentacyclic nitrosyl chelate compound by atoms of nitrosyl bond in α-nitroso-β-naphthol together with Fe(Ⅲ)on hematite surface.Mean- while,the nonuniform multilayer physical adsorption is also occurred.

Cobalt Determination by Means of Flow Injection On-line Sorbent Preconcentration-Flame Atomic Absorption Spectrometry with 1-Nitroso-2-naphthol as a Complexing Reagent

The suitability of 1-nitroso-2-naphthol(NN) as a complexing agent for on-line preconcentration of cobalt eluted on the C_(18) microcolumn by means of the FI-FAAS system was tested. Various parameters affecting the complex formation and its elution were optimized. A 2.3×10^(-3) mol/L reagent solution and the aqueous sample solution acidified with 0.1% (volume fraction) nitric acid were on-line mixed (6.4 mL/min) on a reaction coil set at (65±1)℃ and flowed through the microcolumn for 30 s. The pH of the mixed solution was adjusted to 3—4 with HNO_3(1 mol/L) or NaOH(1 mol/L). The adsorbed complexes in the microcolumn were eluted into the nebulizer of FAAS in 10 s with ethanol acidified with 1% HNO_3(3.0 mL/min). A good precision(1.6% for 100μg/L Co(Ⅱ), n=10), a high enrichment factor 17.2, with detection limit (3σ) 3.2μg/L, and sample throughput (90 h^(-1)) were obtained. The method was applied to the certified reference materials(CRMs), NBS-362 and NBS-364, for the determination of cobalt and the results were in good agreement with the certified values.

Solid-Liquid Extraction of Some Lanthanide Complexes with 1-Nitroso-2-Naphthol

The extraction behavior of Sm(III), Eu(III),Er(III) and Yb(III) with 1- nitroso -2-naphthol (HA) in paraffin has been studied. The composition of,extracted complexes has been determined to be LnA(3) by slope analysis method. The effect of temperature on extraction system is also investigated and thermodynamic parameters are obtained.

A Convenient Preparation of Enantiopure 1,1'-bi-2-naphthols via an Inclusion Complexation in the Solid State

Inclusion reaction of reaction 1, 1'-bi-2-naphthol and (S)-proline was examined uuder the solid state and the solid-liquid conditions. The results indicated that a solid mixture of racemic 1, 1'-bi-2-naphthol and (S)-proline in a 1 : 1 molar ratio was kept at 50-80 for 3-4 h, followed by treatment with benzene to give an insoluble solid and a benzene solution, from which (S)- (- )- and (R)-(+)-1, 1'-bi-2-naphthols of a modest level or optical purity were obtained. Arter 'kinetic' crystallization, both essentially enantiopure iso- mers were provided in 15%-35 % overall yields ,respectively.

Synthesis and Evaluation of Two Novel Naphthol Derivatives as Novel Cholinesterase Inhibitors

Two novel naphthol derivatives（1 and 2） were synthesized and characterized via IR,~1H NMR,and HRMS.The structure of compound 2 was verified by single-crystal X-ray crystallography.It crystallizes in monoclinic,space group C2/c with a = 21.6725（9）,b = 6.0127（3）,c = 25.5405（14） A,β = 94.716（5）o,V = 3316.9（3） A^3,Z = 8,F（000） = 1384,D_c = 1.511 Mg/m^3,M_r = 377.22 and μ = 2.487 mm^-1.In addition,their cholinesterase inhibitory activities in vitro toward Electrophorus electricus acetylcholinesterase（eel ACh E） and horse serum butyrylcholinesterase（eq BCh E） were further determined.The results showed that compound 1 as a new acetylcholinesterase（ACh E） inhibitor displayed higher ACh E inhibitory activity（IC_（50） = 1.4 μM）,which could be considered for Alzheimer＇s disease therapeutics.

Effects of 1-Naphthol on Physiological Parameters of Chlorella vulgaris

[ Objective] This study aimed to investigate the effects of 1-naphthol on primary productivity in aquatic ecosystems. [ Method] The effects of 1-naphthol on biomass, chlorophyll a content, malondialdehyde （MDA） content and soluble protein content of Chlorella vulgaris were investigated. [ Result] 1-Naphthol could significantly inhibit the growth of Chlorella vulgaris. On the 7^th d, the biomass of Chlorella vulgaris exposed to 1.0, 3.0, 6.0, 12.0 and 18.0 mg/L 1-naphthol was 60.26%, 48.15%, 41.32%, 28.59% and 27.10% of that in control respectively, exhibiting a significant dose-response relationship. Chlorella vulgaris was exposed to different concentrations of 1-naphthol （0, 1,5 and 10 mg/L） for 7 d ; with the increase of 1-naphthol concentration, chlorophyll a content of Ch/orella vulgaris was reduced, MDA content increased gradually, soluble protein content increased first and then declined. [ Conclusion] According to the experimental results, 1-naphthol can significantly inhibit the growth of Chlorella vulgaris, thus reducing primary productivity in aquatic ecosystems.

New Method for Preparation of 1-Amidoalkyl-2-Naphthols via Multicomponent Condensation Reaction Utilizing Tetrachlorosilane under Solvent Free Conditions

An efficient and direct procedure for the synthesis of amidoalkylnaphthol derivatives employing a multi-component and one-pot condensation reaction of 2-naphthol, aromatic aldehyde and ace-tonitrile in the presence of tetrachlorosilane (TCS). A binary reagent from (TCS)/ZnCl2 was used upon applying benzonitrile.

Environmentally Benign Synthetic Protocol for O-Alkylation of <i>β</i>-Naphthols and Hydroxy Pyridines in Aqueous Micellar Media

Ultrasonic and microwave-assisted practical methods have been developed for the O-alkylation of aryl (β-naphthols) and Heteroaryl (hydroxy pyridines) in aqueous surfactant media in good to excellent yields. The developed methods are simple, efficient, economical and environmentally safe. Our novel methods describe a set of green methods to Wil-liamson synthesis.