16768-46-0Relevant academic research and scientific papers
A method for continuously preparing azo dye in micro-reactors
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Paragraph 0048-0054; 0055; 0056, (2018/04/01)
The invention discloses a method for continuously preparing azo dye in micro-reactors in the field of dye synthesis. The azo dye is prepared by firstly subjecting a sodium nitrite solution, an aromatic primary amine and an inorganic acid to a diazotization reaction at room temperature in a first micro-reactor to generate an aromatic primary amine diazonium salt; and then subjecting the aromatic primary amine diazonium salt and a coupling component to a coupling reaction in a second micro-reactor to generate the azo dye. Continuous preparation of the azo dye is achieved by utilizing the micro-reactors, a process is simple, a reaction period is short, and a reaction process can be easily monitored and controlled. Addition of an excessive amount of the sodium nitrite and the coupling agent to increase the reaction speed is not required so that raw materials are saved and the method is environmentally friendly. Reaction liquid in the micro-reactors achieves high-speed collision mixing, a uniform reaction environment is formed immediately, the reaction efficiency is high, and the yield and quality of a reaction product are greatly improved.
Spectrophotometric Determination of Aromatic Amines by the Diazotization-Coupling Technique with 8-Amino-1-hydroxynaphthalene-3,6-disulfonic Acid and N-(1-Naphthyl)ethylenediamine as the Coupling Agents
Norwitz, George,Keliher, Peter N.
, p. 807 - 809 (2007/10/02)
A comprehensive study is made of the application of the diazotization-coupling spectrophotometric technique to the determination of diverse aromatic amines, using H-acid (8-amino-1-hydroxynaphthalene-3,6-disulfonic acid) and N-(1-naphthyl)ethylenediamine (also called N-(1-naphthalenyl)-1,2-ethanediamine or N-na) as the coupling agents.The methods were tested successfully on halogenate anilines, 2,4-dichloroaniline, nitroanilines, methylanilines, aminobenzoic acids, aminobenzenesulfonic acids, sulfanilamide, and certain other substituted anilines.The methods are not rec ommended for phenylenediamines and aminophenols, which produce little or no color.The aromatic amines containing negative groups tend to couple and produce colors more readily than aromatic amines not containing such groups.The amount of reagent and time required for full color development is less for aromatic amines containing negative groups, specially for the N-na method.Both methods are about equal in accuracy but the N-na mathod is on the average about 1.6 times more sensitive than the H-acid method.
