Chemiluminescence from alkoxy-substituted acridinium dimethylphenyl ester labels

Chemiluminescent acridinium dimethylphenyl ester labels are used in automated immunoassays for clinical diagnostics. Light emission from these labels is triggered by alkaline peroxide in the presence of the cationic surfactant cetyltrimethylammonium chloride (CTAC). The surfactant plays a critical role in the chemiluminescence process of these labels by both accelerating their emission kinetics and increasing total light output enabling high throughout and improved assay sensitivity in automated immunoassays. Despite the surfactant's crucial role in the chemiluminescent reaction, no study has investigated how structural perturbations in the acridinium ring could impact the influence of the surfactant. We describe herein the synthesis and properties of three new alkoxy-substituted, acridinium dimethylphenyl esters where the nature of the alkoxy group in the acridinium ring was varied (hydrophobic or hydrophilic). Chemiluminescence measurements of these alkoxy-substituted labels indicate that hydrophilic functional groups in the acridinium ring, in particular sulfobetaine zwitterions, disrupt surfactant-mediated compression of emission times but not enhancement of light yield. These results support the hypothesis that surfactant-mediated effects require the binding of two different reaction intermediates to surfactant aggregates and, that surfactants influence light emission from acridinium esters by two separate mechanisms. Our studies also indicate that preservation of both surfactant effects on acridinium ester chemiluminescence and low non-specific binding of the label can be achieved with a relatively hydrophobic acridinium ring coupled to a hydrophilic phenolic ester leaving group.     

Effect of surfactants on the chemiluminescence of acridinium dimethylphenyl ester labels and their conjugates

Chemiluminescent acridinium dimethylphenyl esters, containing two methyl groups flanking the phenolic ester bond, display excellent chemiluminescence stability and are used as labels in automated immunoassays for clinical diagnostics. Light emission from these labels is triggered with alkaline peroxide in the presence of the cationic surfactant cetyltrimethylammonium chloride. Under these conditions, light emission is rapid and is complete in <5 s. In the present study we examined the effect of various surfactants on light emission from acridinium dimethylphenyl ester labels and their conjugates containing hydrophilic linkers derived either from hexa(ethylene)glycol or a sulfobetaine zwitterion. Sulfobetaine zwitterions are very polar and incorporation of these functional groups in acridinium dimethyphenyl esters and their conjugates represents a new approach to improving the aqueous solubility of these chemiluminescent labels. Our results indicate that in general, surfactants affect light emission from these labels and their conjugates by two discrete mechanisms. Cationic surfactants, but not anionic or non-ionic surfactants, accelerate overall light emission kinetics and a more modest effect is observed with zwitterionic surfactants. Surfactants also enhance total light output and the magnitude of this enhancement is maximal for cationic surfactants and a sulfobetaine zwitterionic surfactant. These observations are the first to clearly delineate the role of the surfactant on the chemiluminescence reaction pathway of acridinium esters and can be rationalized based on known effects of surfactant aggregates on bimolecular and unimolecular reactions.     

阴离子表面活性剂聚二硫二丙烷磺酸钠的合成

利用硫化钠与硫磺反应制备二硫化钠,然后将二硫化钠与1,3-丙磺酸内酯反应,合成了一种可作为电镀添加剂的阴离子表面活性剂——聚二硫二丙烷磺酸钠(SPS)。采用核磁共振氢谱对合成产物进行结构表征,确认了产物结构及产率。通过正交试验研究了产物产率与反应物配比、反应温度、溶剂加入量等因素之间的关系,找出了最优合成条件:第一步合成二硫化钠的反应中,硫化钠/硫磺物质的量比为1∶1.3,温度55℃,加水量18 mL;第二步合成SPS的反应中,1,3-丙磺酸内酯/硫化钠物质的量比为1.7∶1,温度40℃,溶剂量75 mL,产物的最高产率可达到95.8%。     

Reusable polymer-supported copper catalyst for one-pot synthesis of 1-alkyl- and 1-aryl-1,2,3-triazoles: green,simple, and effective

Abstract

Polymer-supported copper-catalyzed one-pot synthesis of 1,4-disubstituted 1-alkyl- and 1-aryl-1,2,3-triazoles via 1,3-dipolar cycloaddition of alkyl halides or arylboronic acids, sodium azide, and phenylacetylene has been developed. Reactions went smoothly at room temperature using PEG/H₂O or methanol as solvent to afford the corresponding triazoles in good to excellent yields. The catalyst could be recovered by simple filtration and reused several times with slightly decrease in its activity.     

Development of a Novel Chemiluminescent Probe with a Higher Efficiency than LucigeniiT

A many efforts have been made to take advantage of the chemiluminesce of lucigenin and acridine derivatives, especially for analytical purposes. Aryl acridinium esters have been used as labels for the immunoassay of both large and small molecules. Lucigenin is more stable and higher quantum yield than acridinium ester,but it has not been used as labels in immunoassay and DNA probes,because it dose not have a label moiety group, so for.     

Microwave assisted sulfopropylation of N-heterocycles using 1,3-propane sultone

Dramatic rate acceleration was observed for N-sulfopropylation of heterocyclic compounds (1a-h) using 1,3-propane sultone(2) under microwave irradiation affording the N-sulfopropylated compounds (3a-h) in 68–95% yield.     

Preparation of zwitterionic electron acceptors and donors

The reactions of 4, 4'-bipyridine and nicotinamide with 1, 3-propane sultone yields zwitterionic electron acceptors. Reaction of dimethylaminoethyl ferrocene with 1, 3-propane sultone yields a zwitterionic ferrocene electron donor. The electron acceptors and donor are reduced and oxidized to the respective radical anions and ferrocenyl cation. Dipropyl-4, 4'-bipyridinium disulfonate and the ferrocene derivative quench the excited Ru(bipy)₃²⁺.     

Brønsted acidic ionic liquid [HMIm]BF4 promoted simple and efficient one-pot green synthesis of isoxazolyl-1,3-benzoxazines at ambient temperature

Abstract

Brønsted acidic ionic liquid [HMIm]BF₄ has been used as a nonvolatile, ecofriendly solvent, and catalytic medium for the one-pot green synthesis of isoxazolyl-1,3-benzoxazines. The reaction afforded excellent yield in short reaction time, and avoids multistep synthesis. The easy of recyclability of the IL makes the reaction economically and potentially viable for commercial applications.     

SYNTHESES OF BRANCHED POLY(ETHER KETONE)S WITH PENDANT FUNCTIONAL GROUPS BASED ON 1,1,1-TRIS(4-HYDROXYPHENYL)ETHANE

ABSTRACT

1,1,1-Tris(4-hydroxyphenyl)ethane, THPE, was silylated with chlorotrimethylsilane and the silylated THPE was polycondensed with 1,4-bis(4-fluorobenzoyl)benzene, BFBB, in dry N-methylpyrrolidone. The resulting poly(ether ketone) had a moderate molecular weight and contained a significant fraction of cyclic oligomers and polymers. The pendant trimethylsiloxy group allowed an in situ alkylation with chloropropionitrile, allylbromide, 3,4-dichlorobenzyl chloride, 4-nitrobenzyl bromide, 1,3-propane sultone and 1,4-butane sultone. The latter alkylating agents yielded poly(ether ketone)s having pendant sulfonic acid groups. Further functional groups were introduced by acylation of the pendant free OH-group (resulting from the hydrolysis of the Me₃SiO group) with acetic anhydride, methacrylic anhydride, cinnamoyl chloride and undecenoyl chloride.     

PEG-600-mediated,green and efficient,tandem syntheses of N-subtituted-2-styrylquinazolin-4- ones

Polyethylene glycol (PEG)-mediated, green and efficient, tandem syntheses of N-subtituted-2-styrylquinazolinones are being reported. Condensation of anthranilamide (1) with acetic anhydride in PEG-600, at 100°C for 1 hr gave 2-methyl-3H-quinazoline-4-one (2). Treatment of 2 with benzaldehydes in PEG-600, at 100°C for 2–3 hr, gave 2-styrylquinazolinone-4-ones (3) in excellent yields. Treatment of 3 (a–d) either with dimethyl sulfate (DMS), diethyl sulfate (DES), or with Ph-CH₂-Cl, individually in PEG-600, at 100°C for 1–2 hr without using any base, followed by simple processing resulted in N-substituted-2-styrylquinazolin-4-ones 5 (a–l). In an alternative approach, reaction of 4 (a–c) with benzaldehydes in PEG-600, at 100°C for 1–2 hr, without using any base, followed by simple processing resulted in 5 (a–l). 4 (a–c) were prepared by treatment of 2 with either DMS, DES, or with Ph-CH₂-Cl, individually, in the presence of PEG-600 as reaction medium, at 100°C for 1–2 hr without using any base. Both the sequence of reactions, 1 2 3 5 or 1 2 4 5 could be carried out in tandem in an efficient manner in PEG-600 without the isolation of any intermediates. The structures of all the new compounds synthesized in this work have been established on the basis of their spectroscopic data and analytical data.     

1,3-二-(3,3-二甲基-2-甲烯假吲哚)方酸菁染料的合成及其晶体结构

合成了两个新型方酸菁染料3和5。在催化下,2,3,3-三甲基假吲哚不需N- 烷基化,可直接与方酸反应。反应过程中发生了明显的质子转移。结晶学数据表明,分子3的整体位于同一平面;溶剂苯规则地排在方酸四碳的周围, 后者酷似电子陷肼。染料5有良好的水溶性。     

TFAA-H3PO4 mediated rapid and single-step synthesis of mutual prodrugs of paracetamol and NSAIDs

Abstract

A clean and operationally simple method has been developed for the preparation of mutual prodrug using paracetamol and various nonsteroidal anti-inflammatory drugs. The methodology involves use of TFAA/H₃PO₄ in acetonitrile and a variety of mutual prodrugs has been prepared in good yields by using this single-step C–O bond forming reaction.

     

Synthesis and characterization of new epoxy and cyanate ester resins

New epoxide and cyanate ester resins with an aromatic ester backbone namely 1,3-[di-(4-glycidyloxy diphenyl-2,2^′-propane)]-isophthalate (DGDPI) and 1,4-[di-(4-cyanato diphenyl-2,2^′-propane)]-terephthalate (DCDPT) were synthesized and the intermediates were characterized by IR, 1H-/¹³C-NMR spectroscopic methods. The cured products from DGDPI and DHDPI exhibited higher T_g compared with standard epoxy system. The increase in the T_g may be due to the cyanate ester and rigid aromatic backbones present in the curing system.     

Embedded palladium nanoparticles on metal–organic framework/covalently sulfonated magnetic SBA-15 mesoporous silica composite: As a highly proficient nanocatalyst for Suzuki–Miyaura coupling reaction in amino acid-based natural deep eutectic solvent

In this project, the main aim is the design and present a novel and unique heterogeneous nanocatalyst based on a metal–organic framework/covalently sulfonated magnetic SBA-15 mesoporous silica composite with the emphasis on promoting clean and green synthetic transformations and increasing the catalytic properties. In more detail, initially, SBA-15 containing magnetic nanoparticles was functionalized by a 1,3-propane sultone ligand. In the next step, the functionalized mesoporous substrate was used as a scaffold for the growth and synthesis of the zeolite imidazolate framework-8 (ZIF-8) crystals. The obtained composite was further applied as a suitable support for the immobilization of Pd nanoparticles via a post-modification procedure and the generation of heterogeneous catalysts. The prepared Fe₃O₄@SBA-15-SO₃H@ZIF-8@Pd was incorporated as a heterogeneous and green catalyst in the Suzuki coupling reaction in the natural deep eutectic solvent with efficient recyclability.     

RuCl3 anchored onto imine functionalized silica for the aerobic oxidation of benzylic alcohols under liquid phase catalysis

Abstract

RuCl₃ anchored onto imine functionalized silica has been developed as a heterogeneous catalyst for the selective oxidation of benzylic alcohols to aldehydes using molecular oxygen as an oxidant. SiO₂-RuCl₃ was found to be highly stable, passes hot filtration test successfully, and could be recycled several times without significant loss of activity. The SiO₂-RuCl₃ was characterized by Fourier Transform Infrared Spectroscopy (FTIR), Thermogavimetric Analysis (TGA), Scanning Electron Microscope (SEM), Transmission Electron Micrographs (TEM), X-Ray Diffractometry (XRD), and Atomic Absorption Spectrophotometric Analysis (AAS).     

Hydrolysis of new phthalimide-derived esters catalyzed by immobilized lipase

The last step of the production of four phthalimide-derived acids, designed to act as antiasthma drugs, was performed by enzymatic hydrolysis of the respective methyl or ethyl esters. The esters 4-ethyl-[2-(1,3-dioxo-1,3-dihydro-2-isoindoylyl)]-phenoxyacetic methyl ester (PHT-MET), 4-ethyl-[2-(1,3-dioxo-1,3-dihydro-2-isoindoylyl)]-phenoxyacetic ethyl ester, 4-(1,3-dioxo-1,3-dihydro-2-isoindoylyl)-phenoxyacetic ethyl ester, and 2-(1,3-dioxo-1, 3-dihydro-2-isoindoylyl)-phenoxyacetic ethyl ester were hydrolyzed by immobilized lipase. The enzymatic reaction could be used only to produce the desired 4-substituted compounds. The best result that was found to hydrolysis of PHT-MET, and, therefore, that ester was selected for optimization experiments in a three-phase system. Reactions were performed with solid biocatalyst (Lipozyme® RM IM), organic solvent phase (ethyl acetate), and aqueous phase (saturated Na₂CO₃ solution). To optimize the reaction conditions, an experimental design optimization procedure was used. The variables studied were the amount of enzyme, the temperature, and the volume of the aqueous solution. Time course experiments were then performed for different initial enzyme concentrations (0.5, 0.9, and 1.4 U_H/mL of solvent). The optimized reaction conditions found were 20 mg of Lipozyme (0.9 U_H/mL_solvent) and 5.0 mL of Na₂CO_3(sat) at 40°C for 6 h.     

IBX promoted one-pot condensation of β-naphthol,aldehydes, and 1,3-dicarbonyl compounds

Abstract

An efficient and mild protocol has been developed for one-pot condensation of β-naphthol, aldehydes, and 1,3-dicarbolyl compounds in presence of o-iodoxybenzoic acid has been found to be an excellent catalyst for the synthesis of tetrahydrobenzo[a]xanthen-one, 1H-benzo[f]chromen-2-yl)-one via one-pot three-component condensation of β-naphthol, aldehydes, and 1,3-dicarbonyl compounds. Short reaction time, ambient conditions, simple workup, and high yield with selective manner are some of the striking features of the present protocol.     

Convenient synthesis of sulfonyl azides using PEG-400 as an efficient and eco-friendly reaction medium

Sulfonyl azides have efficiently been synthesized via a convenient and environmentally benign procedure, in which sulfonyl chlorides undergo nucleophilic substitution reaction with sodium azide in PEG-400 under mild conditions. The sulfonyl azides were obtained in 84–97% isolated yields.

     

Carbon deposition on meso-porous Al2O3 supported Ni catalysts in methane reforming with CO2

Summary 4-(Trialkylammonio)propansultans (TAAPSs), synthesized by the addition reaction of 1,3-propane sultone (PS) and trialkylamines (TAAs), were developed as new phase transfer catalysts for synthesizing dialkoxymethane. The reaction between alcohol and dibromomethane in a highly alkaline solution of KOH/organic solvent two-phase medium were carried out under phase-transfer catalysis (PTC) using TAAPSs as the catalyst. High conversion of dibromomethane and high selectivity of the product were obtained using TAAPSs as the catalyst.</o:p>     

Lithium bromide as an efficient,green, and inexpensive catalyst for the synthesis of quinoxaline derivatives at room temperature

Abstract

An efficient, simple, and green procedure for the synthesis of quinoxaline derivatives is described. The condensation of 1,2-diamines with 1,2-diketones using lithium bromide (LiBr) in H₂O/EtOH as a green reaction media at room temperature affords the title compounds in high to excellent yields and in short reaction times.