Check patentability & draft patents in minutes with Patsnap Eureka AI!

Method for preparing 3-amino-5-nitro-2,1-benzisothiazole and diazonium salt thereof

A technology of benzisothiazole and diazonium salt, which is applied in organic chemistry and other fields, can solve problems affecting production efficiency, increase reaction cost, increase operation difficulty, etc., and achieve the effect of saving equipment and reducing manufacturing costs

Active Publication Date: 2012-11-28
ZHEJIANG JIHUA GROUP +1
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When it is used in the synthesis of dyes, it must go through the diazotization process. At present, the relatively mature diazotization process in China generally uses the solid (dry powder) of 3-amino-5-nitro-2,1-benzisothiazole through sulfuric acid, Phosphoric acid, acetic acid, propionic acid and other acidic media are dissolved in temperature and then diazotization reaction is carried out. This process has two disadvantages: the raw material of 3-amino-5-nitro-2,1-benzisothiazole must be passed It is purified by cumbersome post-processing methods. This process inevitably produces a large amount of waste acid and waste water, which causes industrial pollution and increases the manufacturing cost of the final product; and a large amount of expensive phosphoric acid, acetic acid, Acids such as propionic acid lead to high manufacturing costs of synthetic dyes and lose market competitiveness
The literature lies in the diazotization of 3-amino-5-nitro-2,1-benzisothiazole directly using the solid (dry powder) of 3-amino-5-nitro-2,1-benzisothiazole, which greatly The reaction cost is increased, the waste liquid in the refining process is discharged to pollute the environment, and the diazotization method adopts the trans-diazo method to increase the difficulty of operation, reduce the utilization rate of equipment, and affect the production efficiency

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Synthesize 40 g of 2-cyano-4-nitroaniline according to the prior art to obtain 45 g of dry product of 2-amino-5-nitrothiobenzamide; dissolve it in 190 g of 85% sulfuric acid at 50° C., and add 1 g of bromine Carry out ring closure reaction at 45-50°C for 8 hours to obtain 3-amino-5-nitro-2,1-benzisothiazole sulfuric acid solution, directly add nitrosyl sulfuric acid to carry out diazotization reaction at -5-0°C , kept for 3 hours to obtain 3-amino-5-nitro-2,1-benzisothiazole diazonium salt solution.

[0018] The obtained diazonium salt solution was coupled with 35g of N-ethyl-N-methoxycarbonylethylaniline according to the prior art method to obtain 75.8g of disperse blue 148 (C.I. Disperse Blue 148) dye, with a yield of 80.2% and a dye purity of 93.5 %.

Embodiment 2

[0020] 40g of 2-cyano-4-nitroaniline was synthesized according to the prior art to obtain 45g of dry product of 2-amino-5-nitrothiobenzamide; dissolved in 120g of 90% sulfuric acid at 70°C, and added 0.5g Bromine and 1.0g sodium bromide were subjected to a ring-closing reaction at 75-80°C for 6 hours to obtain 3-amino-5-nitro-2,1-benzisothiazole sulfuric acid solution, which was directly added to nitrosyl sulfuric acid at 25-30 The diazotization reaction was carried out at ℃ for 5 hours to obtain 3-amino-5-nitro-2,1-benzisothiazole diazonium salt solution.

[0021] The obtained diazonium salt solution was coupled with 35g of N-ethyl-N-methoxycarbonylethylaniline according to the prior art method to obtain 80.7g of disperse blue 148 (C.I. Disperse Blue 148) dyestuff, yield 85.5%, dyestuff purity 92.8 %.

Embodiment 3

[0023] Synthesize 40 g of 2-cyano-4-nitroaniline according to the prior art to obtain 45 g of dry product of 2-amino-5-nitrothiobenzamide; dissolve it in 120 g of 70% sulfuric acid at 80° C., and add 1 g of bromine Carry out ring closure reaction at 90°C for 8 hours to obtain 3-amino-5-nitro-2,1-benzisothiazole sulfuric acid solution, directly add nitrosyl sulfuric acid to carry out diazotization reaction at -5~0°C, keep After 3 hours, a solution of 3-amino-5-nitro-2,1-benzisothiazole diazonium salt was obtained.

[0024] The obtained diazonium salt solution was coupled with 35g of N-ethyl-N-methoxycarbonylethylaniline according to the prior art method to obtain 77.6g of disperse blue 148 (C.I. Disperse Blue 148) dyestuff, yield 82.2%, dyestuff purity 92.6g %.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a method for preparing 3-amino-5-nitro-2,1-benzisothiazole and a diazonium salt thereof. In the method, o-nitro-p-thiocyanatoaniline is used as a raw material, a thionation reaction, a ring-closure reaction and the like are performed to obtain sulfuric acid solution of 3-amino-5-nitro-2,1-benzisothiazole, and the sulfuric acid solution of 3-amino-5-nitro-2,1-benzisothiazole is directly subjected to diazotization without separation to obtain qualified solution of the diazonium salt of 3-amino-5-nitro-2,1-benzisothiazole. The preparation method can prepare high-quality diazonium salt of 3-amino-5-nitro-2,1-benzisothiazole and has the advantages of simple synthesis process, less equipment, simple and convenient process control, high yield, less waste gas, waste liquid and waste residue, and the like.

Description

technical field [0001] The invention relates to a preparation method of an organic compound and its diazonium salt, in particular to a preparation method of 3-amino-5-nitro-2,1-benzisothiazole and its diazonium salt. Background technique [0002] 3-Amino-5-nitro-2,1-benzisothiazole is an intermediate for the synthesis of blue dyes such as disperse blue 148 and disperse blue 367. Due to the excellent application performance of the synthesized dyes, the color depth is high and the color is relatively bright. Bright, with excellent washing and sublimation fastness, it has been widely used in the development of new structural dyes in recent years to synthesize high-end dyes with excellent application performance. When it is used in the synthesis of dyes, it must go through the diazotization process. At present, the relatively mature diazotization process in China generally uses the solid (dry powder) of 3-amino-5-nitro-2,1-benzisothiazole through sulfuric acid, Phosphoric acid,...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C07D275/04
Inventor 简卫陈美芬汪雪松
Owner ZHEJIANG JIHUA GROUP
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com