2581-69-3Relevant academic research and scientific papers
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.
Micellar catalysis in the systems arylamine-diphenylamine-NO 2-
Doronin, S. Yu.,Chernova
scheme or table, p. 2019 - 2024 (2009/04/12)
By methods of UV and IR spectroscopy and thermogravimetry reactions of diazotizaion and azo coupling were studied in the systems of primary arylamine (p-nitro-, p-carboxy- and p-sulfoaniline)- diphenylamine -nitrite ion in water and micellar media on the basis of surfactants. The micellar catalysis effect of sodium dodecylsulfate in the micellar media was revealed. Rate of diazotization was shown to be independent of the surfactants of various types. Formation of ionic associates of azo dyes with dodecylsulfate anions in premicellar region was established and physicochemical characteristics of the associates were estimated.
Electronic spectra of push-pull 4-phenylaminoazobenzene derivatives
Makita, Shohei,Saito, Ayako,Hayashi, Makoto,Yamada, Shohei,Yoda, Koji,Otsuki, Joe,Takido, Toshio,Seno, Manabu
, p. 1525 - 1533 (2007/10/03)
A series of push-pull type 4-phenylaminoazobenzene derivatives bearing an electron-withdrawing 4'-substituent were probed by electronic spectra in solution. The visible absorption maxima of these azobenzenes were correlated with the solvent parameters through the McRae theory as well as the solvent donor numbers. While the absorption spectra of these neutral species were solvent-dependent, those of protonated species were almost solvent independent. On the other hand, the absorption maxima and the rates of thermal cis-to-trans isomerization in a given solvent were correlated with Hammett constants. These results are discussed with the help of semi- empirical molecular-orbital calculations and compared with previously published data on related compounds.
Functionalized Azo Dyes by Direct Ullmann Coupling
Miller, R. D.,Lee, V. Y.,Twieg, R. J.
, p. 245 - 246 (2007/10/02)
A variety of thermally stable 4-(N,N-diarylamino)-4'-nitroazobenzene dyes can be produced by direct copper-mediated C-N bond formation on preformed amino substituted azo dyes, thus avoiding a troublesome azo coupling step; the products are useful chromophores for high temperature nonlinear optical applications.
Anion-catalyzed Phase-transfer Catalysis. I. Application to Diazo-coupling Reactions
Iwamoto, Hidetoshi,Yoshimura, Masaji,Sonoda, Takaaki,Kobayashi, Hiroshi
, p. 796 - 801 (2007/10/02)
Anion-catalyzed phase-transfer catalysis was evidenced in the diazo-coupling reactions of the arenediazonium ion with a range of diazophile components in liquid-liquid- and liquid-solid two-phase systems.The tetrakisborate ion was effective as an anionic catalyst to accelerate the reactions.Comparisons of the reaction rates in the two-phase system with those in solution systems indicated that the acceleration was due to the increased activity of the cationic reagent, partly by solubilization and partly by the dehydration of such cationic species in the nonpolar organic phase.
TETRAKISBORATE AS THE FIRST EFFICIENT NEGATIVELY CHARGED PHASE TRANSFER CATALYST. KINETIC EVIDENCES
Kobayashi, Hiroshi,Sonoda, Takaaki,Iwamoto, Hidetoshi,Yoshimura, Masaji
, p. 579 - 580 (2007/10/02)
Remarkable acceleration was observed by use of sodium tetrakisborate as a negatively charged phase transfer catalyst for diazonium ion in the azo coupling reactions of aryl diazonium tetrafluoroborate with a range of diazophile components in liquid-liquid- and liquid-solid two-phase systems.Kinetics of the reactions was examined to confirm the phase transfer catalysis.
