6471-46-1Relevant articles and documents
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.
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
Valizadeh, Hassan,Shomali, Ashkan,Ghorbani, Jalal,Noorshargh, Saeideh
, p. 64 - 71 (2015/03/04)
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.
Substituent effect on the tautomerization of 1-arylazonaphthalen-2-ols by mass spectrometric analysis
Lin, Shaw-Tao,Lin, Lee-Hui,Lin, Yi-Cang,Ding, Mei-Fan
, p. 257 - 262 (2015/03/31)
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.
Mesomorphism Dependence on Terminal/Lateral Substitution of Nonlinear Azoester Molecules
Prajapati,Doshi
, p. 28 - 36 (2015/10/05)
A novel azo ester homologous series of liquid crystals (LCs) 2(4′-n-alkoxy benzoyloxy) napthyl 1 azo-3″ nitrobenzenes consists of eleven members of a series with enantiotropic nematogenic mesophase formation and without exhibition of smectogenic property by all the eleven homologs. The nematogenic mesophase textures are threaded or Schlieren. Solid-nematic and nematic-isotropic transition curves of the phase diagram behave in normal manner except for the decyloxy, dodecyloxy, and tetradecyloxy homologs. Analytical and spectral data confirm the molecular structures of homologues. Thermal stability for the nematic phase is 132.6°C, and the degree of mesomorphism varies between 34°C and 79°C and the series if of a middle-ordered melting type. An odd-even effect is observed for the N-I transition curve with alternation of transition temperatures. The LC behavior of the series is compared with other structurally similar known homologous series to establish the relation between mesomorphism and molecular structure.
Synthesis of dyes from aromatic C-nitroso-N-hydroxytriazenes
Churkina,Belyaev,Kazak
, p. 680 - 682 (2007/10/03)
Aromatic C-nitroso-N-hydroxytriazenes can be used as stable forms of diazo compounds for preparation of azo dyes.
New dry arenediazonium salts, stabilized to an exceptionally high degree by the anion of o-benzenedisulfonimide
Barbero, Margherita,Crisma, Marco,Degani, Lacopo,Fochi, Rita,Perracino, Paolo
, p. 1171 - 1175 (2007/10/03)
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.
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
Masoud, Nabil K.,Ishak, Mona F.
, p. 927 - 932 (2007/10/02)
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.
A Simple Route for the Synthesis of Chlorosubstituted Arylazobenzenes, Arylazonaphtalenes, and Arylazopyrazoles
Guenther, R.,Jaehne, E.,Hartmann, H.,Schulze, M.
, p. 945 - 954 (2007/10/02)
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.
Synthesis and Reactions of Phenolic Alkylbenzylnitrosamines
Bowman, Peter J.,Brown, Ben R.,Chapman, M. Andrew,Doyle, Paul M.
, p. 701 - 770 (2007/10/02)
N-Alkyl-p-hydroxybenzylnitrosamines have been synthesised from p-benzoyloxybenzaldehydes via imines and amines which were nitrosated before removal of the protecting group with n-propylamine.N-Alkyl-o-hydroxybenzylnitrosamines were similarly obtained from o-methoxymethoxybenzaldehydes, the final deprotection being achieved with dilute acid.The nitrosamines decompose in hot aqueous alkali by two mechanisms, one through a quinone methide to yield a benzyl alcohol and the other by an elimination eventually yielding a benzaldehyde.The decomposition of the nitrosamines in the presence of 2-naphthol in alkaline solution results in alkylation of the naphthol and production of compounds from the reaction of 2-naphthol with the intermediate quinone methides.The N-sec-butylnitrosamines alkylate 2-naphthol on carbon but the N-methylnitrosamines alkylate on oxygen and during the methylation 94percent of deuterium exchange with methyl hydrogen occurs in deuterium oxide and there is 6percent intact transfer of the methyl group from the N-methylnitrosamine to the 2-naphthol.
