1602-30-8Relevant articles and documents
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
Valizadeh, Hassan,Shomali, Ashkan
experimental part, p. 1138 - 1143 (2012/03/27)
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.
Photooxidation of Arylazo-Naphtholes with Singlet Oxygen
Becker, H. G. O.,Franze, J.
, p. 957 - 964 (2007/10/02)
The reaction of p-substituted 4-arylazo-1-naphtholes 1 and 1-arylazo-2-naphtholes 5 with singlet oxygen (produced by methylene blue-sensitized photolysis) has been studied spectroscopically in methanol as a solvent.The rate constants of dye bleaching are the same, irrespective whether the extinctions of the azo or the hydrazone forms of the tautomeric systems are measured.Both reaction series 1 and 5 afford linear Hammett plots, which is discussed in the light of the azo-hydrazone equilibrium of the dyes and an "ene" mechanism of the reaction with singlet oxygen.It could be shown by short-time spectroscopy that the azo-hydrazone isomerization proceeds much faster than the attack of singlet oxygen on the hydrazone form, which explains all observed facts.
