The method of preparing an azo reactive disperse dye specific fluid precursor

The present invention provides a method for preparing supercritical CO2 fluid specific azo reactive disperse dye precursor, is at 0 ~ 5 ℃, a certain proportion of 2-chloro-4-nitroaniline, hydrochloric acid, nitrous acid sodium diazotized in a mixed solvent of polyethylene glycol 200 and water formed, and then an appropriate amount of urea was added to remove excess nitrous acid. In the above-described diazonium salt was then added to the reaction system aniline coupling reaction, and adjusting the pH of the reaction solution with an alkaline solution; diluted with deionized water, filtered, washed after the reaction, and dried in vacuo to give a specific supercritical fluid CO2 azo dyes of the active precursor. Preparation method of the present invention provides a simple procedure, mild conditions, high product yield, product quality, and to avoid the use of conventional diazotization reaction of high concentrations of acid, the reaction process is easy to control and carry out safer operation, and highly efficient, green, environmental protection and other features.