6410-10-2Relevant articles and documents
Silver nanoparticles as highly efficient and selective optical probe for sulphide via dendrimer formation in aqueous medium
Sanskriti, Isha,Upadhyay
, p. 14563 - 14569 (2016)
We herein report a highly efficient, cost effective, convenient as well as selective colorimetric probe for sulphide (S2-) in the form of silver nanoparticles (AgNPs) capped by an azonaphthol viz. 1-[(4-nitrophenyl)azo]-2-naphthol. A naked eye color change from bright yellow to colorless was observed upon the addition of S2- to the AgNPs. A remarkable feature of this probe is the unique morphological transition of spherical AgNPs to dendritic architecture induced by S2-. Although dendritic AgNPs have been reported previously also by many workers through various methods. Here we are presenting a probe that not only selectively recognises S2- colorimetrically but at the same time paves the way for the self-assembled dendritic structure of AgNPs. The lowest detection limit for S2- was found to be 67 nM which is much lower than the maximum endurable level (15 μM) of S2- in drinking water by World Health Organisation (WHO).
One-pot synthesis of azo compounds in the absence of acidic or alkaline additives
Cheng, Xin-Wang,Duan, Pan,Liu, Ting-Ting,Yan, Jiao-Zhao,Zeng, Yao-Fu
, p. 486 - 490 (2020/10/22)
A one-pot method for the synthesis of azo compounds by the reaction of β-naphthol with aryl amines using t-BuONO as the nitrosonium source in DCM at room temperature was developed. This method features mild reaction conditions, a simple experimental procedure, and is free of acidic or alkaline additives.
Two-Phase Electrochemical Generation of Aryldiazonium Salts: Application in Electrogenerated Copper-Catalyzed Sandmeyer Reactions
Goljani, Hamed,Tavakkoli, Zahra,Sadatnabi, Ali,Nematollahi, Davood
supporting information, p. 5920 - 5924 (2020/08/12)
The electrochemical generation of aryldiazonium salts from nitroarenes in a two-phase system (ethyl acetate/water) was reported for the first time. Some compounds including azo, azosulfone, and arylazides were prepared in good yields with good purity. Cathodically generated aryldiazoniums and anodically produced copper(Ι) ions were used to perform Sandmeyer reactions. To improve the method, an H-type self-driving cell equipped with a Zn rod as an anode was introduced and used for two-phase aryldiazonium production.
A quantitative one-pot synthesis method for industrial azo pigments with recyclable wastewater
Feng, Guangyuan,Zhu, Meiling,Liu, Lei,Li, Chunbao
supporting information, p. 1769 - 1776 (2019/04/08)
Most industrial azo pigments are synthesized by diazotization in one pot and then coupling in another. This two-pot process has been transformed into a one-pot method by adding granular PTFE (polytetrafluoroethylene) to a mechanically agitated aqueous mixture of NaNO2, HCl, a diazo component and a coupling component. This method avoids the step of using a base or a surfactant to dissolve the coupling component. The reactions were fast and quantitative. The granular PTFE, wastewater and excess HCl were then reused 11 times without deteriorating the reaction rate and product purity. Altogether, 22 industrial pigments and 3 azo compounds were synthesized and the reaction can produce up to 22.7 g of product in the laboratory. Some reactions require less than 2 equiv. of HCl and a mechanism explaining this is proposed. In addition, an o-nitro group effect is advanced to explain the differences in coupling reaction rates for o-, m- and p-nitroaniline.
Two-photon ultra-low background fluorescent probe as well as preparation method and application thereof
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Paragraph 0062-0070; 0076-0085; 0091-0100, (2019/09/13)
The invention relates to the field of fine chemical engineering, and in particular relates to a design synthesis and application of a two-photon ultra-low background fluorescent molecular probe basedon ketene rearrangement. The synthetic method of the fluorescent probe adopts the following steps: (1) preparing NDN: adding a 2-naphthol solution into a sodium hydroxide solution, and performing treatment to obtain an anhydrous oxygen-free reagent; adding a diazonium salt into an ice bath, and performing stirring; and performing acidification, and performing drying to obtain the NDN; and (2) preparing the fluorescent probe DNHF-H2S: in the anhydrous oxygen-free environment, weighing the NDN and 2,4-dinitrofluorobenzene, adding the weighed NDN and 2,4-dinitrofluorobenzene into DMF, and performing uniform mixing; adding potassium carbonate, and performing stirring; performing heating to 40-60 DEG C, and performing a reaction; and performing cooling to room temperature, adding ice water, andperforming suction filtration to obtain the fluorescent probe. The probe provided by the invention has two-photon imaging, reduces photodamage of living biological samples and fluorophores, reduces background absorption and scattering, and improves spatial resolution and sensitivity.
Method used for synthesizing azo compound using solid particle one kettle method
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Paragraph 0069; 0070; 0071; 0077; 0080; 0083; 0087; 0090, (2019/01/07)
The invention relates to a method used for synthesizing an azo compound using solid particle one kettle method. The method comprises following steps: solid particles are introduced into a reaction container, an inorganic acid, an aromatic primary amine, sodium nitrite, water, and a coupling component are added, mechanism stirring is carried out, when the reaction is monitored to be finished, filtering and rinsing are carried out, and the obtained filter cake is a finished product; or the solid particles are introduced into the reaction container, the inorganic acid, the aromatic primary amine,sodium nitrite, and water are added, mechanical stirring is carried out, after complete conversion of the aromatic primary amine, the coupling component is added, mechanical stirring is carried out,when the reaction is monitored to be finished, filtering and rinsing are carried out, and the obtained filter cake is a finished product. The solid particles are preferably selected from polytetrafluoroethylene particles, haw seeds, or stainless steel sand. The solid particles are added into the reaction system to promote reaction, no pre-heating or alkali adding dissolving of diazo components orthe coupling component is needed; most reaction is finished in 1h; reaction time is short; product quality is high; and reaction filtrate and excess inorganic acid can be recycled for a plurality of times.
Mild preparation method for structural analogs of Sudan I
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Paragraph 0038-0040, (2018/07/30)
The invention discloses a mild preparation method for structural analogs of Sudan I, and belongs to the technical field of organic chemistry. According to the method, dehydrogenation of N'-p-toluenesulfonyl aromatic hydrazine is promoted by utilizing alkali and oxygen in air to form an aryl diazo compound in situ; then a series of 1-aryl azo-2-naphthol Sudan I analogs are prepared by coupling with2-naphthol. By adopting the method disclosed by the invention, the strategy of producing an explosive intermediate in situ is used, so that 1-aryl azo-2-naphthol is conveniently and safely synthesized. The mild preparation method disclosed by the invention is mild in reaction conditions, wide in substrate applicability, simple and convenient to operate, lower in cost, less in by-products, high inproduct purity, and easy to separate and purify and can be suitable for relatively-large-scale preparation.
New generation of nitrite functionalized star-like polyvinyl imidazolium compound: Application as a nitrosonium source and three dimensional nanocatalyst for the synthesis of azo dyes
Shomali, Ashkan,Valizadeh, Hassan,Noorshargh, Saeideh
, p. 409 - 418 (2017/07/24)
The compounds with three-dimensional and ionic structures have attracted considerable attentions because of their unique characteristics as a drug carrier and catalyst. Star-like poly ionic compounds are a new generation of three-dimensional structures which have both; the exclusive ionic features and three-dimensional structures. Recently, we reported the synthesis of diazonium salts from aniline derivatives using carboxyl and nitrite functionalized graphene quantum dots. Methods: Nitrite-functionalized star-like polyionic (NFSP) compound was synthesized as a new generation of three-dimensional nanocatalyst. Herein, the use of NFSP as an efficient reagent and nanocatalyst for the diazotization of aniline derivatives and subsequent synthesis of azo dyes via the reaction with active phenolates under solvent-free conditions was reported. Results: In order to demonstrate the positive impact of NFSP efficiency, the reaction times and yields of the products were compared with other methods and catalysts which have been reported previously. The brilliant performance of NFSP can be ascribed to multifunctional reagent and also trapping the ingredient within catalyst cavities. Conclusion: A highly effective and cost-effective method has been developed for the preparation of azo dyes. In reported method, new three-dimensional catalyst with highly ionic characteristic and multifunctional nitrosonium source is available. These special features reduced the required amount of catalyst, reaction time and also increased the efficiency of catalyst.
Convenient and rapid diazotization and diazo coupling reaction via aryl diazonium nanomagnetic sulfate under solvent-free conditions at room temperature
Koukabi, Nadiya,Otokesh, Somayeh,Kolvari, Eskandar,Amoozadeh, Ali
, p. 12 - 17 (2015/10/05)
For the first time, nanomagnetic-supported sulfonic acid is used for conversion of several types of aromatic amine, containing electron-withdrawing groups as well as electron-donating groups to the corresponding azo dyes in excellent yield. The synthesis of these compounds is described by the sequential diazotization-diazo coupling of various aromatic amines with sodium nitrite, nanomagnetic supported sulfonic acid and coupling agents under solvent-free conditions at room temperature. This new method offers several advantages including short reaction time, mild reaction conditions, avoidance of harmful acids, and simple work-up procedure. More importantly, aryldiazonium salts supported on magnetic nanoparticles (aryl diazonium nanomagnetic sulfate) were sufficiently stable to be kept at room temperature in the dry state.
The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors
Akwi, Faith M.,Watts, Paul
, p. 1987 - 2004 (2016/10/05)
In this paper, a micro-fluidic optimized process for the continuous flow synthesis of azo compounds is presented. The continuous flow synthesis of Sudan II azo dye was used as a model reaction for the study. At found optimal azo coupling reaction temperature and pH an investigation of the optimum flow rates of the reactants for the diazotization and azo coupling reactions in Little Things Factory-MS microreactors was performed. A conversion of 98% was achieved in approximately 2.4 minutes and a small library of azo compounds was thus generated under these reaction conditions from couplers with aminated or hydroxylated aromatic systems. The scaled up synthesis of these compounds in PTFE tubing (i.d. 1.5 mm) was also investigated, where good reaction conversions ranging between 66-91% were attained.
