Preparation process for 4- bromo phenyl hydrazine

A preparation process, bromophenylhydrazine technology, applied in the field of preparation of 4-bromophenylhydrazine, can solve the problems of poor product quality, low product purity, high production cost, etc.

Inactive Publication Date: 2012-03-21
袁雪冲
View PDF0 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The reduction reaction using sodium sulfite as a reducing agent has a long reaction time. Depending on the substituted 4-bromophenylhydrazine, the reaction generally takes several hours or even a few days, and the obtained product has low purity, and the quality of the product cannot be guaranteed; and the price of sodium sulfite higher
Therefore adopt this method to prepare 4-bromophenylhydrazine, not only production cost is high, and product quality is relatively poor

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

[0015] 2.76 g of 4-nitroaniline, 5 ml of 10N hydrochloric acid, stirred and heated to 60-80 °C, after the 4-nitroaniline was completely dissolved, cooled to below 0 °C, and added sodium nitrite solution (13.8 g of sodium nitrite dissolved in 30ml of water), react at 0-5°C for 5 minutes, filter to remove residue, and obtain a diazonium salt solution.

[0016] Weigh 2.76 grams of sodium metabisulfite, dissolve it in 25ml of water, then add 5ml of 10N sodium hydroxide to make a sodium metabisulfite alkali solution, add the above diazonium salt solution at 5-10°C, adjust the pH to 7-8, and adjust the pH to 7-8 at 15-35 It was reacted at ℃ for 30 minutes, then 10ml of 10N hydrochloric acid was added, and after reacting at 50-90℃ for 30 minutes, it was cooled to room temperature and filtered. Treat in 125ml of 10N hydrochloric acid at 55-90°C for 30 minutes, filter again, collect the filtrate, and dry to obtain 4-nitrophenylhydrazine hydrochloride product (99.5%).

[0017] The same...

Embodiment 2

[0019] Add 3.44 grams of 4-sulfonylaminoaniline, 10 ml of water, and 5 ml of 10N hydrochloric acid into a 100 ml flask, stir to dissolve, and after cooling to below 0°C, add sodium nitrite solution (composed of 1.38 grams of sodium nitrite and 2.76 ml of water) , react at 0-5°C for 5 minutes, filter to remove residue, and obtain diazonium salt solution.

[0020] Sodium pyrosulfite 6.4g, water 25ml, 10N sodium hydroxide 5ml, stirring and dissolving to make sodium pyrosulfite alkaline solution, after cooling to 10-20°C, add the above diazonium salt solution, adjust the pH to 7-8, at 20-30 After reacting at ℃ for 30 minutes, add 10ml of 10N hydrochloric acid and heat to 90-103℃. After reacting for 30 minutes, add 0.1 g of activated carbon, or filter the residue and cool to 10℃ to filter, purify, and dry to obtain the product. The instrument detects that its purity is 99.5%.

[0021] In the same way, 3-fluorophenylhydrazine, 4-sulfonic acid phenylhydrazine, 2- and 4-carboxyphenyl...

Embodiment 3

[0023] 2 grams of 4-methoxyaniline, 4 ml of water, 3.8 ml of 10N hydrochloric acid, stir to dissolve, cool to 0 ° C, add nitrous acid solution (composed of 1.12 g of sodium nitrite and 2.12 ml of water), at 0-5 ° C After reacting for 5 minutes, filter to obtain diazonium salt solution.

[0024] 6.4 grams of sodium pyrosulfite, 10 ml of water, 2.5 ml of 10N sodium hydroxide were stirred to form a sodium pyrosulfite alkaline solution, cooled to 10-20°C, and the above-mentioned diazonium salt solution was added. React at 20-35° C., pH=6-8 for 30 minutes, filter, and collect the filtrate.

[0025] Dissolve the above filtrate in 3ml of water, add 0.3ml of glacial acetic acid and 0.3g of zinc powder at 50°C, raise the temperature to 70-90°C, react for 5 minutes, filter to remove residue, add 2ml of 10N hydrochloric acid to the filtrate, Collect the filtrate and purify it with ethanol to obtain 4-methoxyphenylhydrazine, whose purity is 99.1% as detected by high-pressure liquid chrom...

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 preparation process for 4- bromo phenyl hydrazine. The method is characterized in that arylamine is adopted as an initial raw material, a 4- bromo phenyl hydrazine product is obtained after diazotization reaction, reduction reaction, purification and drying sequentially, reducing agent of the reduction reaction is sodium metabisulfite, and the reduction reaction is carried out under conditions that temperature ranges from 10 DEG C to 35 DEG C and pH (potential of hydrogen) is 7. A 4- bromo phenyl hydrazine product prepared by the preparation method is excellent, and production cost is low.

Description

technical field [0001] The invention relates to a preparation process of 4-bromophenylhydrazine. Background technique [0002] Phenylhydrazine and its derivatives are the main raw materials for the preparation of derivatives such as pyrazolone and indole. The traditional preparation method uses aromatic amine as the starting material, generates diazonium salt through diazotization reaction, then reduces the diazonium group to hydrazine group with sodium sulfite alkali solution, and then obtains 4-bromophenylhydrazine product through purification and drying. The reduction reaction using sodium sulfite as a reducing agent has a long reaction time. Depending on the substituted 4-bromophenylhydrazine, the reaction generally takes several hours or even a few days, and the obtained product has low purity, and the quality of the product cannot be guaranteed; and the price of sodium sulfite higher. Therefore adopt this method to prepare 4-bromophenylhydrazine, not only production ...

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 Applications(China)
IPC IPC(8): C07C243/22C07C241/02C07C311/37C07C303/40C07C309/46C07C303/22
Inventor 袁雪冲
Owner 袁雪冲
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap