Unlock instant, AI-driven research and patent intelligence for your innovation.

Catalytic hydrogenation preparation method of 3,5-diaminobenzoic acid

A technology of diaminobenzoic acid and dinitrobenzoic acid is applied in the field of catalytic hydrogenation preparation of 3,5-diaminobenzoic acid, and can solve the problems of low yield, explosion of hydrazine hydrate, poor product color and the like, Achieve the effect of reducing energy consumption, reducing three wastes, and improving application prospects

Inactive Publication Date: 2014-08-27
江苏恒祥化学股份有限公司
View PDF3 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Compared with iron powder reduction, hydrazine hydrate reduction avoids the generation of iron sludge and reduces the amount of waste water, but its reduction is often accompanied by reduction of other side chains, and the product quality is difficult to control; at the same time, the concentration of hydrazine hydrate required is higher and the hydrazine hydrate It must be excessive, and there are certain difficulties in catalyst selection and preparation. There are certain safety hazards in the storage and transportation of high-concentration hydrazine hydrate. At the same time, there is also a risk of explosion in the production and application of hydrazine hydrate. At the same time, there are also disadvantages of low yield and poor color of the product.

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

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Catalytic hydrogenation preparation method of 3,5-diaminobenzoic acid
  • Catalytic hydrogenation preparation method of 3,5-diaminobenzoic acid

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0018] Add 50 grams of 3,5-dinitrobenzoic acid, 9.4 grams of sodium hydroxide, and 200 grams of water into a 1L autoclave. After stirring evenly, add 0.5 grams of self-made Pd / C. After nitrogen replacement for 3 times, control the hydrogen pressure for 3 -4MPa, 50-60 degrees, react until the pressure does not drop, recover the catalyst by membrane filtration, then acidify with hydrochloric acid to a pH value of 4-4.5, and obtain 34 grams of off-white solid after suction filtration and drying, with a yield of 95.1%. Above, purity (HPLC) 99.3%.

example 2

[0020] Add 100 grams of 3,5-dinitrobenzoic acid, 18.8 grams of sodium hydroxide, and 500 grams of water into a 1L autoclave. After stirring evenly, add 1 gram of self-made Pd / C. After nitrogen replacement for 3 times, control the hydrogen pressure for 3 -4MPa, 50-60 degrees, react until the pressure does not drop substantially, recover the catalyst by membrane filtration, then acidify with hydrochloric acid to a pH value of 4-4.5, and obtain 68.5 grams of off-white solid after suction filtration and drying, with a yield of 95.5%. Above, purity (HPLC) 99.3%.

example 3

[0022] Add 120 grams of 3,5-dinitrobenzoic acid, 22.5 grams of sodium hydroxide, and 600 grams of water into a 1L autoclave. After stirring evenly, add 1.2 grams of self-made Pd / C. After nitrogen replacement for 3 times, control the hydrogen pressure for 3 -4MPa, 50-60 degrees, react until the pressure does not drop substantially, recover the catalyst by membrane filtration, then acidify with hydrochloric acid to a pH value of 4-4.5, and obtain 82.4 grams of off-white solid after suction filtration and drying, with a yield of 95.8% Above, purity (HPLC) 99.4%.

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 the technical field of organic synthetic chemistry, in particular to a catalytic hydrogenation preparation method of 3,5-diaminobenzoic acid. According to the catalytic hydrogenation preparation method of the 3,5-diaminobenzoic acid, the 3,5-diaminobenzoic acid is prepared through an environment protecting process catalytic hydrogenation technology, the process can reduce three wastes, using of toxic hydrazine hydrate is avoided, energy consumption is reduced, the most important is that the automatic production can be adopted, the yield of the product can reach more than 95%, the product is a white to off-white solid body, the purity reaches more than 99%, and the application prospect of the product is improved to the maximum extent.

Description

technical field [0001] The invention relates to the technical field of organic synthesis chemistry, in particular to a method for preparing 3,5-diaminobenzoic acid by catalytic hydrogenation. Background technique [0002] 3,5-diaminobenzoic acid is an important monomer of new material polyimide film, polyimide film is a kind of high temperature resistant new polymer material with excellent comprehensive performance, widely used in high temperature resistant coating, magnet wire , semiconductor protective layer, flexible printed circuit board, solar modules and other fields, the tough and transparent polyimide film synthesized with 3,5-diaminobenzoic acid as a monomer maintains the excellent performance of the original polyimide at the same time , can effectively improve the problem of high-strength and firm bonding between the film and other materials. [0003] In addition, 3,5-diaminobenzoic acid is also an important dye and pharmaceutical intermediate, and a series...

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
IPC IPC(8): C07C229/60C07C227/18C07C227/06
Inventor 邱志刚雍成松
Owner 江苏恒祥化学股份有限公司