New derivatives of benzoxazolinones and benzoxazolinethiones

N-(Aryloxycarbonyl)benzoxazolin-2-ones have been obtained from benzoxazolinones and aryl chloroformates and from N-(chlorocarbonyl) benzoxazolinones and phenols. These compounds possess acylating properties and with phenols in the presence of phenoxide ions they give diaryl carbonates.     

Development of a pressurized liquid extraction-solid-phase extraction followed by liquid chromatography-electrospray ionization tandem mass spectrometry method for the quantitative determination of benzoxazolinones and their degradation products in agricultural soil

A new analytical method for the quantitative determination of benzoxazolinones and their degradation products in agricultural soils based on the use of pressurized liquid extraction (PLE) followed by solid-phase extraction (SPE) and then instrumental determination using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS) is described. Using this method, the characterization, separation and quantitative detection of a mixture of two benzoxazolinones, benzoxazolin-2-one (BOA) and 6-methoxybenzoxazolin-2-one (MBOA) and their degradation products, 2-aminophenol (APH), N-(2-hydroxyphenyl)malonamic acid (HMPMA), 2-amino-3-H-phenoxazin-3-one (APO), 9-methoxy-2-amino-3-H-phenoxazin-3-one (AMPO), 2-acetylamino-3-H-phenoxazin-3-one (AAPO) and 2-acetylamino-9-methoxy-2-amino-3-H-phenoxazin-3-one (AAMPO) was achieved. The complete LC-ESI-MS-MS precursor-product ion fragmentation pathways for the degradation products of benzoxazolinones are described for the first time. Quantitative analysis was done in the multiple reaction mode using two specific combinations of precursor-product ion transitions for each compound. The optimized method was quality assessed by the measure of parameter as recovery, linearity, sensitivity, repeatability and reproducibility. Recoveries of the analytes ranged from 53 to 123%. The developed method offered improvements to the sensitivity as compared with our previously LC-MS method, with detection limits down to 2.4-21 ng/g of dry weight. This achievement allows us to identify and quantify for the first time degradation products of benzoxazolinones in real agricultural soil samples. Analytes were found in the range of 20.6-149 ng/g dry weight.     

Acid-catalyzed intramolecular cyclization of N-(4,4-diethoxybutyl)sulfonamides as a novel approach to the 1-sulfonyl-2-arylpyrrolidines

Herein we report our studies on the acid-catalyzed cyclisation of N-(4,4-diethoxybutyl)sulfonamides at the presence of polyatomic phenols as an efficient one-pot approach to the synthesis of 1-sulfonyl-2-arylpyrrolidines from the acyclic precursors.     

1,1-Dichloro-2,2,2-trihaloethyl Isocyanates and N-(1-Chloro-2,2,2-trihaloethylidene)urethanes in the Synthesis of 4-Trihalomethyl-2H-1,3-benzoxazin-2-ones

4-Trihalomethyl-2H-1,3-benzoxazin-2-ones have been synthesized by the reaction of 1,1-dichloro-2,2,2-trihaloethyl isocyanates or N-(1-chloro-2,2,2-trihaloethylidene)urethanes with 3-dialkylamino(alkoxy)phenols. The character of the products from the addition of nucleophiles has been shown to depend on the nature of the nucleophile and the trihalomethyl group.     

Unsaturated 3-acylbenzoxazolinones — Dienophiles in diene synthesis reactions. I

It has been shown that unsaturated 3-acylbenzoxazolinones readily take part in reactions with cyclopentadienes and give good yields of the corresponding 3-(bicyclo[2,2,1]hept-5-ene-2-carbonyl)benzoxazolinones.     

TiCl4促进的N,N-及N,O-缩醛和酚类化合物的傅-克反应

芳香甘氨酸是一类非常重要的非蛋白氨基酸。本文首次实现了易于制备和保存的N,N-及N,O-缩醛在TiCl4的促进下与酚类化合物发生傅-克反应,高产率和高区域选择性合成了一系列邻羟基取代的芳香甘氨酸衍生物。     

Effect of N-pyridyl substitution and hydrogen bonding on the deactivation of singlet excited 1,2-naphthalimide

Photophysical properties of 1,2-naphthalimide (1) and N-(4-pyridyl)-1,2-naphthalimide (2) as well as the effect of their hydrogen bonding with phenols have been studied in toluene. Fluorescence emission is the dominant energy dissipation pathway of the singlet excited 1. Introduction of the 4-pyridyl substituent into the imide moiety significantly accelerates the internal conversion due to the efficient vibronic coupling between close-lying S1 and S2 excited states, however, the rate of triplet formation exhibits negligible change. In contrast with the behavior of the corresponding substituted phenyl derivatives, 2 does not emit dual fluorescence because of the less extensive conjugation within the molecule. Fluorescence quenching with phenols takes place both in dynamic and static processes. Electron transfer is slower in the hydrogen bonded complex where phenols are linked to the pyridyl moiety due to the larger distance between the electron donor and acceptor components.     

Extraction of zinc(ii) from aqueous alkali solutions byortho-derivatives of phenols

The ability of a series of ortho-functionalized phenol derivatives and ofN-(2-hydroximinocyclohexyl)palmitohydroxamic acid to extract Zn²⁺ ions from aqueous alkali solutions (0.2–4.0 mol L^–1) in the presence of trialkylmethylammonium methylsulfate has been investigated. The most active extractants are chelating phenols containing N- and S-coordinating groups and chelates of the pyrocatechol series.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1279–1281, May, 1996.     

3,5-二硝基苯甲酰基高效液相色谱键合硅胶固定相的制备与评价

以N-(β-氨乙基)-γ-氨丙基甲基二甲氧基硅烷为偶联剂,建立了一种制备3,5-二硝基苯甲酰基键合硅胶固定相(DNB)的新方法。采用元素分析、红外光谱和热分析表征了该固定相的结构。根据元素分析碳含量结果,计算出DNB表面配体浓度为2.08 μmol/m2。以芳烃(PAHs)、酚类、芳胺类、硝基苯酚异构体和磺胺类化合物作溶质探针,较系统地研究了该固定相的色谱性能。研究表明,所制备的固定相除了具有弱的疏水性外,还能与溶质发生电荷转移、静电、氢键和偶极-偶极等作用,从而提高对溶质的分离选择性。同时,由于间隔基对硅醇羟基的屏蔽作用,适用于含氮的碱性化合物的分离。     

Surface-functionalized CdS clusters with recognition sites near the interface: selective luminescence response to lipophilic phenols

A series of water-soluble cadmium sulfide clusters bearing an alkyl-chain layer between the inorganic core and the outer PEG layer were synthesized by the ligand-exchange reaction of Cd(10)S(4)(SPh)(12) with thiols functionalized by an N-(ω-PEGylated alkyl) amide moiety. The photoluminescence titration experiments in aqueous media revealed that clusters with a sufficiently hydrophobic inner environment exhibit definite emission enhancements upon the addition of bisphenol A or 4-nonylphenol. The dramatic effect of the alkyl chain length on the emission responses demonstrated that the hydrophobic layer around the inorganic surface serves as guest binding sites to facilitate the access of the lipophilic phenols near the organic-inorganic interface. A marked preference for the lipophilic phenols over related compounds, such as methylated bisphenol A, long-chain n-alkanol, and nonlipophilic phenols, was observed in the emission responses of the "hydrophobic" cluster, suggesting that not only the hydrophobic interaction but also the attractive force involving the phenolic OH group contributes to the positive responses. The results of control experiments and IR studies indicated that the hydrogen bonding interaction between the phenolic OH group and the amide group in the surface organic units is responsible for the positive emission responses. The present work shows that the precise tuning of the molecular recognition environments near the organic-inorganic interface is useful for developing guest-specific functions.     

Anodic fluorination of phenols using Et3N-5HF electrolyte

In the presence of Et₃N-5HF electrolyte, anodic fluorination of phenols (1) successfully afforded 4,4-difluorocyclohexa-2,5-diene-1-ones (11), which were readily converted to p-fluorophenols (9) in good yields by the subsequent reduction with Zn in acidic aqueous solutions. We have revealed some novel information on the oxidation mechanism of 1, which is well supported by the cyclic voltammogram of 1 in Et₃N-5HF.     

Access to Vinyl Ethers and Ketones with Hypervalent Iodine Reagents as Oxy-Allyl Cation Synthetic Equivalents

We report an Umpolung strategy of enol ethers to generate oxy-allyl cation equivalents based on the use of hypervalent iodine reagents. Under mild basic conditions, the addition of nucleophiles to aryloxy-substituted vinylbenziodoxolone (VBX) reagents, easily available in two steps from silyl alkynes, resulted in the stereoselective formation of substituted aryl enol ethers. The reaction was most efficient with phenols as nucleophiles, but preliminary results were also achieved for C- and N- nucleophiles. In absence of external nucleophiles, the 2-iodobenzoate group of the reagent was transferred. The obtained aryl enol ethers could then be transformed into α-difunctionalized ketones by oxidation. The described “allyl cation”-like reactivity contrast with the well-established “vinyl-cation” behavior of alkenyl iodonium salts.     

Comparison of gas chromatography-mass spectrometry and capillary electrophoresis in analysis of phenolic compounds extracted from solid matrices with pressurized hot water

Self-constructed pressurized hot water extraction (PHWE) equipment was used in dynamic mode to extract spiked phenolic compounds (phenol, 3-methylphenol, 4-chloro-3-methylphenol and 3,4-dichlorophenol) from sea sand and soil. Phenols were analyzed by both gas chromatography-mass spectrometry (GC-MS) and capillary zone electrophoresis (CZE) to compare the techniques and to find out if CZE is a suitable tool for analysis of phenols extracted from environmental matrix. Good recoveries of phenols spiked in sea sand were achieved at all PHWE temperatures (50, 100, 200, 300 C). GC-MS studies showed that phenols were selectively extracted from soil at 50 C but various other compounds (e.g. polyaromatic hydrocarbons) were extracted along with the phenols at 300 degrees C. In the case of CZE, phenols extracted from the soil, at 300 C were separated with good resolution at pH 9.7, and co-extracted compounds did not interfere with the analysis. The analytical values obtained by GC-MS and CZE were generally of similar magnitude.     

Multiresidue analysis of acidic and polar organic contaminants in water samples by stir-bar sorptive extraction-liquid desorption-gas chromatography-mass spectrometry

The feasibility of stir-bar sorptive extraction (SBSE) followed by liquid desorption in combination with large volume injection (LVI)-in port silylation and gas chromatography-mass spectrometry (GC-MS) for the simultaneous determination of a broad range of 46 acidic and polar organic pollutants in water samples has been evaluated. The target analytes included phenols (nitrophenols, chlorophenols, bromophenols and alkylphenols), acidic herbicides (phenoxy acids and dicamba) and several pharmaceuticals. Experimental variables affecting derivatisation yield and peak shape as a function of different experimental PTV parameters [initial injection time, pressure and temperature and the ratio solvent volume/N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) volume] were first optimised by an experimental design approach. Subsequently, SBSE conditions, such as pH, ionic strength, agitation speed and extraction time were investigated. After optimisation, the method failed only for the extraction of most polar phenols and some pharmaceuticals, being suitable for the determination of 37 (out of 46) pollutants, with detection limits for these analytes ranging between 1 and 800 ng/L and being lower than 25 ng/L in most cases. Finally, the developed method was validated and applied to the determination of target analytes in various aqueous environmental matrices, including ground, river and wastewater. Acceptable accuracy (70-130%) and precision values (<20%) were obtained for most analytes independently of the matrix, with the exception of some alkylphenols, where an isotopically labelled internal standard would be required in order to correct for matrix effects. Among the drawbacks of the method, carryover was identified as the main problem even though the Twisters were cleaned repeatedly.     

The electrochemical fluorination of N-(ω-chloroalkyl)pipecolines and N-(ω-chloroalkyl)hexamethyleneimines

Electrochemical fluorinations of six kinds of N-(ω-chloroalkyl)pipecolines [N-(2-chloroethyl)-2-, N-(3-chloropropyl)-2-, N-(2-chloroethyl)-3-, N-(3-chloropropyl)-3-, N-(2-chloroethyl)4- and N-(3-chloropropyl)-4-pipecolines] and two kinds of N-(ω- chloroalkyl)-substituted hexamethyleneimines [N-(2-chloroethyl)- and N-(3-chloropropyl)hexamethyleneimines] were conducted. From these starting materials, corresponding chlorine-retained fully fluorinated amines together with ring isomerized products were formed in yields of 7.6～14.8% from the former and 5.4～5.5% from the latter, respectively. New chloropolyfluoroamines obtained in the present investigation have been isolated and characterized by spectroscopic (infrared, ¹⁹F nmr and mass) and elemental analysis.     

Determination of phenols in landfill leachate-contaminated groundwaters by solid-phase extraction

A solid-phase extraction method for phenols in landfill leachates was developed and optimized in order to solve the expected and observed problems associated with an anaerobic matrix containing high concentrations of salts and organic matter. Isolute ENV+ cartridges exhibited the best retention of phenols of the four sorbents examined, and was the only cartridge which a 1 L leachate sample could pass through. With the other cartridges, clogging made this impossible. The final method, which included 27 different phenols, gave detection limits of <0.1 microg/L (drinking water concentration limit for pesticides) for most phenols (25), and for 12 phenols <0.01 microg/L. Recovery rates (determined for four concentrations in the range 1-25 microg/L, two replicates of each) were in the range 79-104% (SD 1-12%), except for phenol (26+/-1.3%) and 2-methoxyphenol (62+/-4.2%). Up to 12 different phenols could be identified in leachates from three Danish landfills, ranging in concentration from 0.01 to 29 microg/L, which is at the lower end of the concentration range usually found for phenols in landfill leachates (sub-microg/L to mg/L).     

Determination of phenols by liquid chromatography after online adsorption preconcentration on the Strata-X adsorbent

An online adsorption-high-performance liquid chromatography (HPLC) method was developed for the determination of phenols (11 priority water pollutants) in waters, using polystyrene chemically modified with N-vinyl-2-pyrrolidone (Strata-X). The detection limits for phenols obtained using a preconcentration from 10 mL of water and calculated by different means vary from 0.3 to 2 μg/L. The accuracy of the determination of phenols in tap and river water samples was verified by the standard addition method.     

Synthesis of 4-arylmorpholine -2,3-diones by the reaction of n-(2-hydroxyethyl)arylamines with diethyl oxalate

The corresponding 4-arylmorpholine-2,3-diones were obtained by the reaction of N-(2-hydroxyethyl)aniline, N-(2-hydroxypropyl)aniline, N-(2-hydroxyethyl)-p-chloroaniline, and N-(2-hydroxyethyl)-p-anisidine with diethyl oxalate. The N-(2-hydroxyethyl)-o-, p-, and m-toluidines and N-(2-hydroxyethyl)-o-anisidine form 1,4-(ditolyl)piperazines and 1,4-di(o-anisyl)piperazine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 22–24, January, 1971.