Synthetic method of phenylhydrazine

A synthetic method, the technology of phenylhydrazine, which is applied in the field of synthesis of aromatic hydrazine compounds, can solve the problems of ineffective reaction and reduced yield, and achieve the effects of high recycling value, reduced water consumption, and less waste water

Active Publication Date: 2015-05-13
江苏艾科维科技有限公司
View PDF5 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the above-mentioned traditional process, only increasing the amount of water dissolved in sodium sulfite can alleviate the heat release caused by the pH change, but the amount o...

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
  • Synthetic method of phenylhydrazine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Embodiment 1, a kind of preparation method of phenylhydrazine, take aniline, dilute sulfuric acid, ammonium nitrite, ammonium sulfite, ammonium bisulfite, ammonia as raw material, carry out following steps successively:

[0032] 1). Measure 50ml of 50wt% sulfuric acid (0.36mol), add it into a 500ml three-necked flask, weigh 18.63g of aniline (0.20mol) and add it, a large amount of solids are precipitated, and then cool down to 0°C in an ice-salt bath. Add 90ml (2.20mol / L) ammonium nitrite solution dropwise, the dropping time is 30min, the temperature is controlled at 0-5°C during the dropwise addition, keep the temperature for 5min after the dropwise addition, and then cool down to -10°C in the ice-salt bath .

[0033] 2). Weigh 30g (0.26mol) of ammonium sulfite and 18g (0.18mol) of ammonium bisulfite into the three-necked flask directly, stir vigorously (rotating speed is 800-1200rmp), when the temperature of the reaction system naturally rises slowly to 40°C Finally,...

Embodiment 2

[0036] Embodiment 2, a kind of preparation method of phenylhydrazine, take aniline, dilute sulfuric acid, ammonium nitrite, ammonium sulfite, ammonium bisulfite, ammonia as raw material, carry out following steps successively:

[0037] 1). Take 42ml of 60wt% sulfuric acid (0.39mol), add it into a 500ml three-necked flask, weigh 18.63g of aniline (0.20mol) into it, and precipitate a large amount of solids, then cool down to 0°C in an ice-salt bath. Add 90ml (2.20mol / L) ammonium nitrite solution dropwise, the dropping time is 30min, the temperature is controlled at 0-5°C during the dropwise addition, keep the temperature for 5min after the dropwise addition, and then cool down to -10°C in the ice-salt bath .

[0038] 2). Weigh 30g of ammonium sulfite (0.26mol) and 18g of ammonium bisulfite (0.18mol) into the three-necked flask directly, stir vigorously (rotating speed is 800-1200rmp), when the temperature of the reaction system naturally rises slowly to 40°C Finally, 60wt% sulf...

Embodiment 3

[0041] Embodiment 3, a kind of preparation method of phenylhydrazine, take aniline, dilute sulfuric acid, ammonium nitrite, ammonium sulfite, ammonia as raw material, carry out following steps successively:

[0042]1). Measure 60ml of 50wt% sulfuric acid (0.43mol), add it into a 500ml three-neck flask, weigh 18.63g of aniline (0.20mol) and add it, a large amount of solids are precipitated, and then cool down to 0°C in an ice-salt bath. Add 90ml (2.20mol / L) ammonium nitrite solution dropwise, the dropping time is 30min, the temperature is controlled at 0-5°C during the dropwise addition, keep the temperature for 5min after the dropwise addition, and then cool down to -10°C in the ice-salt bath .

[0043] 2). Weigh 45g of ammonium sulfite (0.39mol) and add it directly into a three-necked flask, stir vigorously (rotating speed: 800-1200rmp), when the temperature of the reaction system naturally rises slowly to 40°C, add 50wt% sulfuric acid (about 50ml) The pH was adjusted to 3, ...

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 discloses a synthetic method of phenylhydrazine. The synthetic method comprises the following steps: adding dilute sulfuric acid into aniline, dropwise adding ammonium nitrite at 0-5 DEG C, and then performing thermal reaction for 4-6 minutes; then cooling to a temperature between -5 and -10 DEG C, adding a solid reducing agent, and stirring violently; when the temperature of the reaction system naturally rises to be more than 40 DEG C, adding dilute sulfuric acid to adjust the pH value to be 2-4, and heating to 70-100 DEG C to react for 4-6 hours; and separating the obtained reaction product to obtain phenylhydrazine. According to the synthetic process of phenylhydrazine, disclosed by the invention, aniline is used as a raw material, dilute sulfuric acid is used as salt forming and acidifying reagents, ammonium nitrite is used as a diazotization reagent, ammonium sulfite and/or ammonium hydrogen sulfite is used as the reducing agent, ammonia gas is used for neutralizing a reaction solution, phenylhydrazine is finally obtained by virtue of extraction and distillation, and a byproduct salt is single ammonium sulfate.

Description

technical field [0001] The invention relates to a method for synthesizing aromatic hydrazine compounds, in particular to a method for synthesizing phenylhydrazine, a chemical intermediate of organic synthesis. Background technique [0002] Phenylhydrazine, whose molecular formula is C 6 h 8 N 2 , its structural formula is as follows: [0003] [0004] Phenylhydrazine is an important fine chemical intermediate. The synthesis method of phenylhydrazine mainly uses aniline as raw material at present, and obtains through steps such as diazotization, reduction, hydrolysis, neutralization, and distillation. Patent WO 2012065062 mentions the use of SnCl 2 The preparation of phenylhydrazine by reduction of diazonium salt is expensive and not suitable for industrial production. In addition, the more reducing agents used in industry are sodium sulfite, ammonium sulfite, sodium bisulfite and ammonium bisulfite, but a large amount of water is used as sulfite or bisulfite in the ...

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): C07C243/22C07C241/02
Inventor 潘炯彬钱超刘建青陈新志
Owner 江苏艾科维科技有限公司
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