Method used for preparing disperse blue 360

Abstract

The present invention discloses a method for preparing disperse blue 360. 2-Bromothiazole is used as a raw material and is subjected to four unit reaction processes of nitration, hydrazination, amination and oxidation to obtain the target product. Its specific route is as follows: 2-bromothiazole is used as a raw material and subjected to a nitration reaction under the action of a mixture of concentrated nitric acid and concentrated sulphuric acid using to produce 2-bromo-5-nitrothiazole, the resulting 2-bromo-5-nitrothiazole is reacted using 2-methyltetrahydrofuran as a solvent under the action of hydrazine hydrate to produce 2-hydrazino-5-nitrothiazole, the resulting 2-hydrazino-5-nitrothiazole is reacted with 3-methyl-4-chloro-N,N-diethylaniline under the action of triethylamine, cuprous bromide and butanol to produce 2-[[4-(diethylamino)-2-methylphenyl]diamine]-5-nitrothiazole, the prepared 2-[[4-(diethylamino)-2-methylphenyl]diamine]-5-nitrothiazole is reacted under the action of an oxidant to produce the target product. In the present invention, sodium perborate and a composite catalyst are used for the hydrazine oxidation, which solves the problem of a low conversion rate of hydrazine oxidation using hydrogen peroxide as an oxidant, and provides a new preparation method for synthesizing the azo dye.

Description

technical field [0001] The invention relates to a method for preparing a known disperse dye, specifically a method for synthesizing disperse blue 360, which belongs to the field of manufacturing chemical dyes. Background technique [0002] Disperse Blue 360, the chemical name is 2-[[4-(diethylamino)-2-methylphenyl]azo]-5-nitrothiazole, it is a new type of heterocyclic azo disperse dye, insoluble For who and ethanol, it is blue in concentrated sulfuric acid. The dye has bright color, high light absorption coefficient, high dyeing strength, excellent lifting rate, good discharge performance, light fastness and smoke fastness. It is mainly used for dyeing and printing of polyester and blended fabrics, and can also be used for Dyeing of microfibers. Its molecular formula is C 14 h 17 N 5 o 2 S, the relative molecular mass is 319.3. The structural formula of disperse blue 360 ​​is: [0003] [0004] Disperse blue 360 ​​is a relatively new dye variety, which is an envir...

AI Technical Summary

Problems solved by technology

[0006] This method has the deficiencies in the following aspects. First, the synthesis difficulty of 2-amino-5-nitrothiazole is relatively large, the yield is low, and the cost is high. Domestic and foreign manufacturers have been looking for its substitutes; secondly, the heterocyclic compound 2 -The diazotization coupling reaction carried out by amino-5-nitrothiazole has many side reactions, the reaction difficulty is large, the cycle is long, the yield is low, and the purity of the product obtained is not high; the third this diazotization coupling reaction is at low temperature It needs to be carried out under the environment, the temperature control is strict, a large amount of frozen brine is needed, and the reaction conditions are relatively harsh, especially in summer, it is a strict test for the refrigeration performance of the refrigeration unit; fourthly, the diazotization coupling reaction produces a large amount of acid waste water, impurities Complicated, difficult to manage, high pressure on the environment

Images