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

Method for preparing 2-fluoride-5-alkoxyl aniline

A technology of alkoxyaniline and fluoronitrobenzene, which is applied in the field of preparation of 2-fluoro-5-alkoxyaniline, can solve problems such as being unsuitable for large-scale industrial production, large safety hazards and the like, and achieves high production capacity, The effect of few side reactions and mild reaction conditions

Inactive Publication Date: 2011-11-16
SHANGHAI CHEMSPEC CORP
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the steps of this method are not long, the fluorinated reagent HF used is a highly carcinogenic and highly toxic compound, which is not suitable for large-scale industrial production, and this method needs to be carried out under relatively high pressure, which has also buried a large safety hazard

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
  • Method for preparing 2-fluoride-5-alkoxyl aniline
  • Method for preparing 2-fluoride-5-alkoxyl aniline

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0054] (1) Preparation of 2-fluoro-5-bromonitrobenzene

[0055] Add 141 grams (1 mol) of o-fluoronitrobenzene and 200 grams of concentrated sulfuric acid into a 500ml four-necked bottle, cool down to 0-10°C under an ice-salt bath, slowly add 132 grams of dibromohydantoin in batches, and keep The temperature is between 0-10°C. After the addition, the temperature was slowly returned to room temperature 25°C, and at the same time, the content of the raw material was tracked by GC until the content of the raw material was less than 1%, poured into ice water, extracted with 200ml of dichloroethane, separated, washed with water, dried, and precipitated to obtain 146.5 g (0.67 mol) of 2-fluoro-5-bromonitrobenzene, with a purity of 98.16% and a yield of 67%.

[0056] (2) Preparation of 2-fluoro-5-bromoaniline

[0057] Add 336 grams of water and 112 grams of Fe powder into a 1L four-necked bottle, add 12ml of 30% concentrated HCl, and heat up to 80°C for activation. When a golden yel...

Embodiment 2

[0061] (1) Preparation of 2-fluoro-5-bromonitrobenzene

[0062] Add 141 grams (1 mol) of o-fluoronitrobenzene and 200 grams of concentrated sulfuric acid into a 500ml four-neck flask, cool down to -10°C under an ice-salt bath, slowly add 132 grams of bromine in batches, and keep the temperature at - 10°C. After the addition, the temperature can be slowly returned to room temperature (25°C). At the same time, GC will track the raw material to less than 1%, pour it into ice water, add 200ml of dichloroethane to extract, separate, wash with water, and dry. Precipitation gave 145.8 g (0.66 mol) of 2-fluoro-5-bromonitrobenzene with a purity of 97.19% and a yield of 66%.

[0063] (2) Preparation of 2-fluoro-5-bromoaniline

[0064] Add 336 grams of water and 112 grams of Fe powder into a 1L four-necked bottle, add 12ml of 30% concentrated HCl, and heat up to 95°C for activation. When a golden yellow solid appears on the wall of the bottle, it means that it has been activated. Slowly...

Embodiment 3

[0068] (1) Preparation of 2-fluoro-5-bromonitrobenzene

[0069] Add 141 grams (1mol) of o-fluoronitrobenzene and 200 grams of concentrated sulfuric acid into a 500ml four-neck flask, cool down to -10°C, slowly add 132 grams of N-bromosuccinimide in batches, and keep the temperature at -10°C. After the addition, the temperature was slowly raised to 50 °C, and at the same time, the content of the raw material was tracked by GC to less than 1%, poured into ice water, extracted with 200ml of dichloroethane, separated, washed with water, dried, and precipitated to obtain 2 -Fluoro-5-bromonitrobenzene 144 g (0.65 mol), purity 92.46%, yield 65.4%.

[0070] (2) Preparation of 2-fluoro-5-bromoaniline

[0071] Add 336 grams of ethanol aqueous solution and 112 grams of zinc powder into a 1L four-neck bottle, add 12ml of 30% concentrated HCl, and heat up to 150°C for activation. When a golden yellow solid appears on the wall of the bottle, it is activated, and slowly drop into the above...

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 method for preparing 2-fluoride-5-alkoxyl aniline. In the method, 2-nitrobenzene is used as raw material for preparing the 2-fluoride-5-alkoxyl aniline by substitution reaction, reduction reaction and etherification reaction. The invention has the advantages of short synthesis route, mild condition, easy industrialization realization, etc. An obtained target product hashigh purity and stable quality and meets the requirement of being used as an intermediate product completely.

Description

technical field [0001] The invention relates to a preparation method of 2-fluoro-5-alkoxyaniline, in particular to a C-containing 1 -C 10 Process for the preparation of alkoxylated 2-fluoro-5-alkoxyanilines. Background technique [0002] 2-Fluoro-5-alkoxyaniline is an increasingly versatile intermediate that is commonly used in the synthesis of pharmaceutical compounds, pesticide compounds, and electronic chemicals. [0003] In the prior art, it is generally to use organometallic reagents to deprotonate o-fluoroaniline at the 5-position, and then react with an electrophile, or by oxidation, to make the 5-position hydroxylated, and then under alkaline conditions, use Treatment with an alkylating reagent affords the corresponding 2-fluoro-5-alkoxyaniline. [0004] However, most of the raw and auxiliary materials used in this method (especially organometallic reagents) are relatively expensive, and the reaction conditions are harsh. [0005] U.S. Patent No. 4,006,185 disclo...

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 Patents(China)
IPC IPC(8): C07C213/00C07C215/76C07C217/84
Inventor 李功勇王学跃王云祥
Owner SHANGHAI CHEMSPEC CORP