Method for preparing phenylhydrazine derivant

A derivative, the technology of phenylhydrazine, applied in the field of preparation of phenylhydrazine derivatives, can solve the problems of poor product quality, high production cost, and product quality cannot be guaranteed

Inactive Publication Date: 2008-03-05
太仓市华联化工实业有限公司
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  • 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 different substituted phenylhydrazine derivatives, the reaction generally takes several hours or even several days, and the purity of the product obtained is low, and the quality of the product cannot be guaranteed; and the price of sodium sulfite higher
Therefore adopt this method to prepare phenylhydrazine derivative, not only production cost is high, and product quality is relatively poor

Method used

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  • Method for preparing phenylhydrazine derivant
  • Method for preparing phenylhydrazine derivant

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] 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.

[0019] 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%).

[0020] The same...

Embodiment 2

[0022] 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.

[0023] 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, heat to 90-103℃, after reacting for 30 minutes, add 0.1 g of activated carbon, filter to remove slag, cool to 10℃, filter, purify, and dry to obtain the product. The instrument detects that its purity is 99.5%.

[0024] In the same way, 3-fluorophenylhydrazine, 4-sulfonic acid phenylhydrazine, 2- and 4-carboxyphenylhydrazin...

Embodiment 3

[0026] 2 grams of 4-methoxyaniline, 4 ml of water, 3.8 ml of 10N hydrochloric acid, stir to dissolve, cool to 0 ° C, add sodium nitrite solution (made up of 1.12 g of sodium nitrite and 2.12 ml of water), at 0-5 After reacting at ℃ for 5 minutes, filter to obtain a diazonium salt solution.

[0027] 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.

[0028] 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 chr...

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Abstract

The present invention relates to phenyl hydrazine derivative preparing process. By using aromatic amine as the initial material, and through diazo reaction, reduction reaction with sodium pyrosulfite as reductant at 10-35 deg.c and in pH 7-9 condition, purifying and drying, phenyl hydrazine derivative product of high quality is produced in low production cost.

Description

technical field [0001] The invention relates to a preparation method of phenylhydrazine derivatives. 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 finally obtains phenylhydrazine derivative products through purification and drying. The reduction reaction using sodium sulfite as a reducing agent has a long reaction time, depending on different substituted phenylhydrazine derivatives, the reaction generally takes several hours or even several days, and the purity of the product obtained is low, and the quality of the product cannot be guaranteed; and the price of sodium sulfite higher. Therefore adopt this method to prepare phenylhydrazi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C243/22C07C241/02
Inventor 沈云汉
Owner 太仓市华联化工实业有限公司
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