- Silver nanoparticles as highly efficient and selective optical probe for sulphide via dendrimer formation in aqueous medium
-
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).
- Sanskriti, Isha,Upadhyay
-
-
Read Online
- One-pot synthesis of azo compounds in the absence of acidic or alkaline additives
-
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.
- Cheng, Xin-Wang,Duan, Pan,Liu, Ting-Ting,Yan, Jiao-Zhao,Zeng, Yao-Fu
-
p. 486 - 490
(2020/10/22)
-
- Two-Phase Electrochemical Generation of Aryldiazonium Salts: Application in Electrogenerated Copper-Catalyzed Sandmeyer Reactions
-
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.
- Goljani, Hamed,Tavakkoli, Zahra,Sadatnabi, Ali,Nematollahi, Davood
-
supporting information
p. 5920 - 5924
(2020/08/12)
-
- A quantitative one-pot synthesis method for industrial azo pigments with recyclable wastewater
-
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.
- Feng, Guangyuan,Zhu, Meiling,Liu, Lei,Li, Chunbao
-
supporting information
p. 1769 - 1776
(2019/04/08)
-
- Two-photon ultra-low background fluorescent probe as well as preparation method and application thereof
-
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.
- -
-
Paragraph 0062-0070; 0076-0085; 0091-0100
(2019/09/13)
-
- Mild preparation method for structural analogs of Sudan I
-
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.
- -
-
Paragraph 0038-0040
(2018/07/30)
-
- Method used for synthesizing azo compound using solid particle one kettle method
-
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.
- -
-
Paragraph 0069; 0070; 0071; 0077; 0080; 0083; 0087; 0090
(2019/01/07)
-
- 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
-
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.
- Shomali, Ashkan,Valizadeh, Hassan,Noorshargh, Saeideh
-
p. 409 - 418
(2017/07/24)
-
- Convenient and rapid diazotization and diazo coupling reaction via aryl diazonium nanomagnetic sulfate under solvent-free conditions at room temperature
-
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.
- Koukabi, Nadiya,Otokesh, Somayeh,Kolvari, Eskandar,Amoozadeh, Ali
-
-
- The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors
-
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.
- Akwi, Faith M.,Watts, Paul
-
p. 1987 - 2004
(2016/10/05)
-
- Carboxyl and nitrite functionalized graphene quantum dots as a highly active reagent and catalyst for rapid diazotization reaction and synthesis of azo-dyes under solvent-free conditions
-
Carboxyl and nitrite functionalized graphene quantum dots was prepared from carboxyl and hydroxyl functionalized graphene quantum dots using NaNO2 in the absence of mineral acids. This functional group conversion was confirmed by FT-IR spectroscopy, photoluminescence and X-ray diffraction. The carboxyl and nitrite functionalized graphene quantum dots was used as an effective nitrosonium ion source and reusable catalyst for the efficient diazotization of a variety of arylamines without using any additional acid. Subsequent azo-coupling of these freshly prepared diazonium salts with a range of active aromatic compounds led to the requisite azo-dyes in excellent yields in very short reaction times with a simple experimental procedure.
- Valizadeh, Hassan,Shomali, Ashkan,Nourshargh, Saideh,Mohammad-Rezaei, Rahim
-
p. 522 - 528
(2015/03/18)
-
- Synthesis of a nitrite functionalized star-like poly ionic compound as a highly efficient nitrosonium source and catalyst for the diazotization of anilines and subsequent facile synthesis of azo dyes under solvent-free conditions
-
Nitrite functionalized star-like poly ionic (NFSPI) compound was synthesized and used as a highly efficient nitrosonium source and catalyst for the conversion of aniline derivatives to diazonium salts. Azo dyes were prepared via in situ azo-coupling reaction of these diazoniums with active aromatic compounds under solvent-free conditions in very short reaction time in excellent yields. NFSPI plays dual role as a three-dimensional nitrosonium source and catalyst because of its poly ionic characteristic. The isolated products were confirmed with FT-IR spectrum, 1H-NMR, 13C-NMR spectroscopy and CHNSO analysis. The structure of heterogeneous reagent and catalyst was confirmed by FT-IR spectrum, SEM images, EDX and CHNSO analysis. Yields and reaction times for the synthesis of a variety of products via this procedure were compared with reported values in literature.
- Valizadeh, Hassan,Shomali, Ashkan,Ghorbani, Jalal,Noorshargh, Saeideh
-
-
- An environmentally friendly approach to the green synthesis of azo dyes in the presence of magnetic solid acid catalysts
-
A solvent-free, efficient and green approach for the synthesis of azo dyes has been developed by the diazo coupling reactions of aromatic amines with β-naphthol in the presence of sulfonic acid functionalized magnetic Fe3O4 nanoparticles (Fe3O4@SiO2-SO3H) by a grinding method at room temperature. This green methodology aims to overcome the limitations and drawbacks of the previously reported methods such as low temperature, use of acids, alkalis and toxic solvents, instability of diazonium salts at room temperature, modest yields, and long reaction times. Moreover, the attractive advantages of the process include mild conditions with excellent conversions, simple product isolation process, inexpensive procedure and recyclability of the magnetic catalyst. This journal is
- Safari, Javad,Zarnegar, Zohre
-
p. 17738 - 17745
(2015/06/15)
-
- Substituent effect on the tautomerization of 1-arylazonaphthalen-2-ols by mass spectrometric analysis
-
An electron-ionization (EI) mass spectra of a series of 1-arylazonaphthalen-2-ols was obtained for studying the substituent effect on the fragmentation. The correlation between the ratio, molecular ion and fragment ion, and Hammett's constants is applied to examine the effect of the substituent on the fragmentation. The negative correction between the ratio, Imolecular ion/(I171amu + I143amu + I115amu), and Hammett's constants indicates an electron-withdrawing group destabilized the molecular ion. An unusual long-range hydrogen transfer demonstrates an important role in the fragmentation process Mass spectra of a series of 1-arylazonaphthalen-2-ols were obtained for studying the substituent effect on the fragmentation. The correlation between the ratio of molecular ion and fragment ion, and Hammett's constants is applied to examine the effect of substituent on the fragmentation. The negative correction indicates an electron-with-drawing group destabilized the molecular ion. An unusual long-range hydrogen transfer demonstrates an important role in the fragmentation process.
- Lin, Shaw-Tao,Lin, Lee-Hui,Lin, Yi-Cang,Ding, Mei-Fan
-
p. 257 - 262
(2015/03/31)
-
- Genetic incorporation of a 2-naphthol group into proteins for site-specific azo coupling
-
The 2-naphthol analogue of tyrosine, 2-amino-3-(6-hydroxy-2-naphthyl) propanoic acid (NpOH), has been genetically introduced into proteins in Escherichia coli. This is achieved through the directed evolution of orthogonal aminoacyl-tRNA synthetase/tRNA pairs that selectively charge the target amino acid in response to the amber stop codon, UAG. Moreover, chemoselective azo coupling reactions have been revealed between the 2-naphthol group and diazotized aniline derivatives that are substituted with an electron donating moiety. The coupling reactions required a very mild condition (pH 7) with great reaction rate (less than 2 h at 0 C), high efficiency, and excellent selectivity.
- Chen, Shuo,Tsao, Meng-Lin
-
p. 1645 - 1649
(2013/11/06)
-
- Fluorescent azo disperse dyes from 3-(1,3-benzothiazol-2-yl)naphthalen-2-ol and comparison with 2-naphthol analogs
-
Five novel fluorescent azo disperse dyes were synthesized using different diazotized aromatic amines followed by coupling with 3-(1,3-benzothiazol-2-yl) naphthalen-2-ol. These dyes were characterized by FT-IR, 1H NMR and mass spectroscopy. These azo disperse dyes were applied on polyester and their fastness properties were evaluated. A parallel series of dyes using 2-naphthol in place of benzothiazolyl were made to investigate the effect of benzothiazolyl moiety on the fastness properties. This investigation showed that the dyes containing benzothiazolyl residue have better fastness properties than that of the azo disperse dyes based on 2-naphthol. Effect of pH on photo physical properties was also studied.
- Satam, Manjaree A.,Sekar, N.,Raut, Rajesh K.
-
p. 92 - 103,12
(2020/08/20)
-
- Nanoparticles of organosilane-based nitrite ionic liquid immobilized on silica for the diazotization of aniline derivatives and subsequent synthesis of azo dyes
-
Imidazolium based nitrite ionic liquid containing trimethoxysilyl group was prepared from the reaction of N-methylimidazole and (3-chloropropyl) trimethoxysilane. This ionic liquid was immobilized on silica covalently to give nanoparticles with the imidazolium nitrite moiety remaining intact. The diazotization reaction was performed as a model reaction to examine the activity of these nanoparticles as a nitrosonium source. Excellent performance was exhibited in the diazotization reaction of various aniline derivatives in the presence of HCl under mild heterogeneous conditions (room temperature and short reaction time). In-situ coupling of diazonium salts to a range of tertiary anilines, phenols and naphthols afforded the requisite azo dyes in good yield, using standard experimental procedures.
- Valizadeh, Hassan,Amiri, Mohammad,Hosseinzadeh, Fatemeh
-
experimental part
p. 1308 - 1313
(2012/03/27)
-
- A new nitrite ionic liquid (IL-ONO) as a nitrosonium source for the efficient diazotization of aniline derivatives and in-situ synthesis of azo dyes
-
A new task-specific nitrite containing ionic liquid derived from the O-nitrosation of N-methyl-N-hydroxybutylimidazolinium chloride was synthesized and used as a source of nitrosonium ion to affect the efficient diazotization of arylamines. The diazonium salts thus obtained were coupled, using standard experimental procedures, to a range of tertiary anilines, phenols and naphthols to afford the requisite azo dyes in good yield. The diazotization and subsequent azo-coupling generated the related azo dyes at 0-5 °C in short reaction times with a simple experimental procedure.
- Valizadeh, Hassan,Shomali, Ashkan
-
experimental part
p. 1138 - 1143
(2012/03/27)
-
- Synthesis and characterization of Azo dye para red and new derivatives
-
Azo dyes para red was synthesized. The products were characterized by FTIR and UV-Visible spectrophotometers. The antibacterial activities of the compounds were studied using gram positive and gram negative microorganism.
- Al-Rubaie, L Abd-Alredha R.,Mhessn, R. Jameel
-
experimental part
p. 465 - 470
(2012/06/18)
-
- Ionic liquid 1-(3-trimethoxysilylpropyl)-3-methylimidazolium nitrite as a new reagent for the efficient diazotization of aniline derivatives and in situ synthesis of azo dyes
-
A new ionic liquid 1-(3-trimethoxysilylpropyl)-3-methylimidazolium nitrite was synthesized. This ionic liquid was used as a convenient nitrosonium source in diazotization of arylamines into their corresponding diazonium salts which were converted into their related azo dyes via the in situ azo-coupling with aniline derivatives or phenolic compounds. The diazotization of anilines in this ionic liquid and subsequent azo-coupling generated the related azo dyes in good to excellent yields at 0-5 °C in short reaction times via a simple experimental procedure.
- Valizadeh,Amiri,Shomali,Hosseinzadeh
-
experimental part
p. 495 - 501
(2012/07/13)
-
- Arenediazonium o-benzenedisulfonimides: Some kinetics of azo coupling reactions with naphthols
-
Kinetic investigation of azo coupling reactions between naphthols and 4-methoxy- and 4-nitrobenzenediazonium o- benzenedisulfonimides has been carried out for comparison with the related benzenediazonium tetrafluoroborates. The data clearly indicate that the two kinds of diazonium salts show very similar reactivities. This fact emphasizes that arenediazonium o-benzenedisulfonimides, which are very stable, may be used as alternatives to the more usual diazonium salts. The azo coupling reactions between 4-nitro-and 4-methoxybenzenediazonium salts and 1-bromo-2- naphthol, performed with equimolecular amounts of both reagents, showed the unexpected formation of large amounts of 1-bromo-4-nitrobenzene and 1-bromo-4-methoxybenzene. Some mechanistic implications of this behaviour are discussed. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Boga, Carla,Degani, Jacopo,Del Vecchio, Erminia,Fochi, Rita,Forlani, Luciano,Todesco, Paolo E.
-
p. 3837 - 3843
(2007/10/03)
-
- Synthesis of dyes from aromatic C-nitroso-N-hydroxytriazenes
-
Aromatic C-nitroso-N-hydroxytriazenes can be used as stable forms of diazo compounds for preparation of azo dyes.
- Churkina,Belyaev,Kazak
-
p. 680 - 682
(2007/10/03)
-
- One-pot diazo coupling reaction under microwave irradiation in the absence of solvent
-
Diazotization and coupling reactions were carried out in one pot by inducing with microwave irradiation in the absence of solvent.
- Jin, Jin,Wen, Zhong,Long, Jiang,Wang, Yongmei,Matsuura, Teruo,Meng, Jiben
-
p. 829 - 834
(2007/10/03)
-
- New dry arenediazonium salts, stabilized to an exceptionally high degree by the anion of o-benzenedisulfonimide
-
Arenediazonium o-benzenedisulfonimides 3 (20 examples, yield >90%) were prepared in the dry state by diazotization of aromatic amines with (-pentyl nitrite and o-benzenedisulfonimide in glacial acetic acid or formic acid at 0-5°C. Unlike most diazonium salts in the dry state, salts 3 are very highly stable.
- Barbero, Margherita,Crisma, Marco,Degani, Lacopo,Fochi, Rita,Perracino, Paolo
-
p. 1171 - 1175
(2007/10/03)
-
- Synthesis of porphyrins with reactive groups on phenyl rings. 8. Azo dyes on tetraphenylporphyrins
-
Porphyrins having covalently attached residues of azo dyes on the periphery of the molecule have been synthesized by the diazotization of tetraaminophenylporphyrins and subsequent azo coupling of the diazonium salts with phenol, and with α- and β-naphthols. The possibility of π - π electron interaction of the two chromophoric systems has been studied. 1997 Plenum Publishing Corporation.
- Syrbu,Semeikin,Syrbu
-
p. 897 - 901
(2007/10/03)
-
- Kinetics and Mechanism of the Diazo Coupling Reaction of Arenediazo Methyl Ethers with β-Naphthol. Part 1. The Rates of Reaction in Nonaqueous Acid Solutions
-
Rate data are presented for the diazo coupling reaction of arenediazo methyl ethers with β-naphthol in solutions of dioxane, ethanol, and propan-2-ol acidified with hydrochloric acid at 25 deg C.Over range of HCl concentrations studied, pseudo-first-order rate constants were obtained and the reaction was found to be of first order in diazo ether.The relationship between the observed rate constants (kobs.) and hydrochloric acid concentration (cHCl) was found to be non-linear.Correlations of reaction rates with the Hammett acidity function (H0) and with the Hammett substituent constant (?x) conform with a mechanism in which the slow step is unimolecular decomposition of the protonated diazo ether, DEH(1+), to the coupling entity, the diazonium ion, D(1+), which instantly reacts with β-naphthol to give the azo dye.
- Masoud, Nabil K.,Ishak, Mona F.
-
p. 927 - 932
(2007/10/02)
-
- 3-Aryl-1-tetrazol-5-yltriazenes, Bench-stable Arenediazonium Ion Synthons: Synthesis of Biaryls and Aryl Halides
-
3-Aryl-1-tetrazol-5-yltriazenes have been used as a bench-stable source of diazonium ions for the synthesis of substituted biaryls, aryl halides (iodides, bromides, and chlorides) and azo dyes.The dediazoniation process when induced by trihalogenoacetic acid or acetic acid did not involve free radicals.
- Butler, Richard N.,O'Shea, Paul D.,Shelly, Declan P.
-
p. 1039 - 1042
(2007/10/02)
-
- A Simple Route for the Synthesis of Chlorosubstituted Arylazobenzenes, Arylazonaphtalenes, and Arylazopyrazoles
-
The reaction of arylazophenoles and arylazohydroxypyrazoles (or their tautomer hydrazones) 10, 11, and 15 with POCl3 in dimethylformamide yields chlorosubstituted arylazobenzenes or arylazopyrazoles 12, 13 and 16, resp., in moderate to high yields.The substitution of the OH-group by the Cl-moiety is favoured by acceptor substituents in the aryl fragments ortho- and/or para-linked to the azo group.In case that arylazocompounds derived from resorcinol are used the substitution reaction runs in a stepwise manner giving raise to the formation of o-hydroxy-p-chlorosubstit uted azo compounds 18 primarily and then of dichlorosubstituted azo compounds 19.
- Guenther, R.,Jaehne, E.,Hartmann, H.,Schulze, M.
-
p. 945 - 954
(2007/10/02)
-
- THIOSULFONIC ACIDS. XXXI. ARYLAZOARENETHIOSULFONATES
-
Arylazoarenethiosulfonates were obtained, and their structures and chemical characteristics were studied.It was shown that arylazoarenethiosulfonates have a nonionic structure, and this explains their high stability.It was established that they enter with difficulty into reactions with the release of nitrogen, but they enter readily into azo-coupling and reduction reactions.
- Boldyrev, B. G.,Grivnak, L. M.
-
p. 324 - 330
(2007/10/02)
-
