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

Preparation method of 2-br-4-fluoacetanilide

A technology of fluoroacetanilide and p-fluoroaniline, which is applied in the field of preparation of 2-bromo-4-fluoroacetanilide, can solve the problems of unavailable raw materials and low single-step yield, and achieve reduced production costs, high purity, and easy operation. simple effect

Inactive Publication Date: 2011-07-13
KINGCHEM LIAONING CHEMICAL CO LTD
View PDF4 Cites 9 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this process route is simple to operate, the raw materials are not easy to obtain and the single-step yield is low

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
  • Preparation method of 2-br-4-fluoacetanilide
  • Preparation method of 2-br-4-fluoacetanilide

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Example 1: Put 13.9g of p-fluoroaniline into a 250mL four-necked bottle equipped with stirring, thermometer, condenser, and dropping funnel, add 36g of glacial acetic acid under stirring, raise the temperature to 50°C, and add 13g of acetic anhydride dropwise. Then raise the temperature to 55-60°C and keep it for 2h; then cool down to 50-53°C and add 14g of bromine dropwise. Then the temperature was raised to 55-60°C for 1h. After keeping, it was poured into a stirred 250ml aqueous solution containing 2% sodium bisulfite for crystallization, and the crude product was obtained by suction filtration. After refining with 75% ethanol once more, 24 g of finished product was obtained (total yield 82.62%, GC99.95%).

Embodiment 2

[0018] Example 2: Put 69.5 g of p-fluoroaniline into a 1L four-necked bottle equipped with stirring, thermometer, condenser, and dropping funnel, add 113 g of glacial acetic acid while stirring, raise the temperature to 60°C, and add 75 g of acetic anhydride dropwise. Then raise the temperature to 70-80°C and keep for 3h; then cool down to 48-53°C and add 63g of bromine dropwise, after the addition, raise the temperature to 50-60°C and keep for 2h, then cool down to 45-53°C, add 70g of 27% hydrogen peroxide dropwise, Then the temperature was raised to 50-60°C for 3h. After the retention, it was poured into 250 ml of a stirred 4% sodium bisulfite aqueous solution for crystallization, and the crude product was obtained by suction filtration. After refining once with 70% ethanol, 121.5 g of finished product was obtained (total yield 83.64%, GC99.86%).

Embodiment 3

[0019] Example 3: Put 13.9 g of p-fluoroaniline into a 250 mL four-necked bottle equipped with stirring, thermometer, condenser, and dropping funnel, add 23 g of glacial acetic acid while stirring, raise the temperature slightly to 70 ° C, and add 15 g of acetic anhydride dropwise Then raise the temperature to 80-90°C and keep it for 1h; then cool down to 50-55°C and add 13g of bromine dropwise, after the addition, raise the temperature to 55-60°C and keep it for 1h, then cool down to 50-55°C, add 15g of 25% hydrogen peroxide dropwise, Then the temperature was raised to 55-60°C for 1h. After the retention, it was poured into 250 ml of a stirred 6% sodium bisulfite aqueous solution for crystallization, and the crude product was obtained by suction filtration. After refining once with 80% ethanol, 23.8 g of finished product was obtained (total yield 81.93%, GC99.89%).

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 belongs to preparation of compound products of fine chemical engineering and particularly relates to a preparation method of 2-br-4-fluoacetanilide, which comprise the steps of: acetylation: adding para-fluoro aniline and glacial acetic acid into a reaction flask, heating to 50 DEG V, dropping acetic anhydride, carrying out reaction for 1-3h under the condition of 55-100 DEG C to prepare an intermediate para-fluoro acetanilide; and (2) bromination: dropping bromine at 45-55 DEG C, carrying out reaction for 1-3h under the condition of 50-60 DEG C, then dropping hydrogen peroxide at 40-55 DEG C, carrying out reaction for 1-3h under the condition of 50-60 DEG C, decolorizing and crystallizing with sodium hydrogensulfite, recrystallizing with an ethanol water solution to obtain a finished product of the 2-br-4-fluoacetanilide. The 2-br-4-fluoacetanilide has a chemical reaction formula shown in the specification, the whole process is shorter in reaction time and simple in operation, the reaction conversion rate for the acetylation and the bromination is up to above 90%, a finally obtained product has high purity, and the preparation method is suitable for enlarged industrial production; and thus, the production cost is reduced.

Description

technical field [0001] The invention belongs to the preparation of fine chemical compound products, in particular to a preparation method of 2-bromo-4-fluoroacetanilide. technical background [0002] After searching, the preparation methods of 2-bromo-4-fluoroacetanilide reported in patents and non-patent literature at home and abroad are less at present, and mainly contain p-fluoroaniline as raw material through bromination, acetylation preparation method and 2 -A preparation method in which bromoacetanilide is fluorinated as a raw material. [0003] Ishikura Tsukasa Gunji Tomokazu, whose publication number is 01-311056, proposed a method for brominating p-fluoroaniline to obtain a brominated product: he used dichloromethane, chlorobenzene, toluene and other inert solvents as reaction solvents, and added Nitrogen-containing aromatic heterocyclic compounds (such as pyridine, quinoline, lutidine, etc.), use bromine to bromide p-fluoroaniline, react at -10-50°C for several ho...

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): C07C233/15C07C231/12
Inventor 王富民尹丽华张喜军郭玉梅姚路路朱夷新
Owner KINGCHEM LIAONING CHEMICAL CO LTD
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