Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Preparation method of 4-methyl phenylhydrazine sulfate

A technology of methylphenylhydrazine and sulfate, which is applied in the field of preparation of organic compounds, can solve the problems of high impurity content, poor stability, and small output of products, and achieve the effects of improving purity, easy operation, and less impurities

Inactive Publication Date: 2018-03-20
TIANJIN CHEM REAGENT RES INST
View PDF0 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

And the product obtained by the preparation method of existing 4-methylphenylhydrazine sulfate has high impurity content, low purity, poor stability, and small output, which cannot meet the needs of the market

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

[0018] A preparation method for 4-methylphenylhydrazine sulfate, comprising the following steps:

[0019] ⑴ diazotization

[0020] Add 50g of 4-methylaniline and 150ml of 37% concentrated hydrochloric acid into a 1L three-necked flask, cool to 2°C with ice salt, add 85.7g of 35% sodium nitrite aqueous solution while stirring, and keep the temperature at 2°C for 1 hour.

[0021] ⑵ reduction

[0022] Add 450ml of 37% concentrated hydrochloric acid, 450ml of water and 120g of zinc powder in the reaction solution, keep the temperature at 18°C ​​and react until the reaction is complete, the reaction solution becomes off-white, then add 20% sodium hydroxide solution until the pH value of the reaction solution is 10, After 1 hour of heat preservation at 5°C, crystals were precipitated, and 26.5 g of crude 4-methylphenylhydrazine was obtained by filtration.

[0023] ⑶ Purification

[0024] Dissolve 26.5g of crude 4-methylphenylhydrazine in 530g of water, heat it to 60°C to dissolve...

Embodiment 2

[0028] A preparation method for 4-methylphenylhydrazine sulfate, comprising the following steps:

[0029] ⑴ diazotization

[0030] Add 200g of 4-methylaniline and 600ml of 37% concentrated hydrochloric acid into a 5L three-necked flask, cool to 2°C with ice salt, add 343g of 35% sodium nitrite aqueous solution while stirring, and keep the temperature at 2°C for 1.5 hours.

[0031] ⑵ reduction

[0032] Add 730ml of 37% concentrated hydrochloric acid, 730ml of water and 195g of zinc powder to the reaction solution, keep the temperature at 18°C ​​until the reaction is complete, the reaction solution turns off-white, then add 25% sodium hydroxide solution until the pH value of the reaction solution is 10 , kept at 5°C for 1.5 hours, crystals were precipitated, and 122 g of crude 4-methylphenylhydrazine was obtained by filtration.

[0033] ⑶ Purification

[0034] Dissolve 122g of crude 4-methylphenylhydrazine in 2440g of water, heat to 60°C to dissolve it completely, then add an...

Embodiment 3

[0038] A preparation method for 4-methylphenylhydrazine sulfate, comprising the following steps:

[0039] ⑴ diazotization

[0040] Add 500g of 4-methylaniline and 1500ml of 37% concentrated hydrochloric acid into a 10L three-necked flask, cool to 2°C with ice salt, add 857g of 35% sodium nitrite aqueous solution while stirring, and keep the temperature between 0 and 5°C for 1.5 Hour.

[0041] ⑵ reduction

[0042] Add 730ml of 37% concentrated hydrochloric acid, 730ml of water and 480g of zinc powder to the reaction solution, keep the temperature at 18°C ​​until the reaction is complete, the reaction solution turns off-white, then add 30% sodium hydroxide solution until the pH value of the reaction solution is 10 , kept at 5°C for 2 hours, crystals were precipitated, and 285 g of crude 4-methylphenylhydrazine was obtained by filtration.

[0043] ⑶ Purification

[0044] Dissolve 285g of crude 4-methylphenylhydrazine in 5700g of water, heat to 60°C to dissolve it completely, ...

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 preparation method of 4-methylphenylhydrazine sulfate, comprising the steps of diazotization, reduction, purification and salt formation. In the steps of diazotization and reduction, concentrated hydrochloric acid is used to keep the reaction solution in strong acidity, so as to ensure the smooth and complete progress of the reaction. In the reduction step, zinc powder-concentrated hydrochloric acid is used as the reducing agent instead of sodium thiosulfate, sodium bisulfite, stannous chloride-hydrochloric acid, etc., which not only has good reduction performance, high yield, shortens the reaction time, and generates Impurities such as zinc hydroxide are easy to remove, so that the product has less impurities and high purity. Washing with acetone in the salt-forming step not only improves the purity of the product, but also ensures the appearance of the product. The preparation method is stable and reliable in process, easy to operate, high in product purity (the content is ≥ 99.1% as measured by high-performance liquid chromatography), and the yield is ≥ 42%, which fully meets the needs of the market for 4-methylphenylhydrazine sulfate.

Description

technical field [0001] The invention relates to the technical field of preparation of organic compounds, in particular to a preparation method of 4-methylphenylhydrazine sulfate. Background technique [0002] As an important intermediate in organic synthesis, 4-methylphenylhydrazine sulfate is widely used in the dye and pharmaceutical manufacturing industries, and has a broad market prospect. And the product obtained by the preparation method of existing 4-methylphenylhydrazine sulfate has high impurity content, low purity, poor stability, and small output, which cannot meet the needs of the market. Contents of the invention [0003] The object of the invention is to overcome the deficiencies in the prior art, and provide a kind of preparation method of 4-methylphenylhydrazine sulfate with high purity, large output and good stability. [0004] In order to achieve the above object, the present invention adopts the following technical solutions: [0005] A kind of preparat...

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): C07C241/02C07C243/22
CPCC07C241/02C07C245/20C07C243/22
Inventor 申倩
Owner TIANJIN CHEM REAGENT RES INST
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com