The preparation method of acetanilide

A technology of acetanilide and aniline, applied in the field of preparation of acetanilide, can solve problems such as low technological yield, and achieve the effects of low reaction temperature, easy industrialization and improved yield

Active Publication Date: 2020-04-07
新乡市锦源化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The object of the present invention is to provide the preparation method of acetanilide, and described preparation method has solved the low problem of existing process productive rate

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Synthetic acetanilide

[0038] first step:

[0039] Add 0.3 mol of aniline, 0.3 mol of ammonium chloride, 0.2 mol of glacial acetic acid, 0.4 mol of N,N-dimethylacetamide and 0.24 mol of dicyclohexylcarbodiimide into a round-bottomed flask, install an air condenser, Stir and heat up to 120°C, and reflux for 3 hours. After the reaction is complete, stop heating and cool to room temperature naturally.

[0040] Step two:

[0041] Add ice water to the reaction solution in the first step, let it stand still, and when no solid precipitates out, filter it with suction, continue cooling the filtrate to below 0°C, and filter it with suction after the solid is precipitated again, and filter the solid obtained by suction filtration twice Combined, washed with water, and dried to obtain white needle crystals with a yield of 98.3%.

Embodiment 2

[0043] The main difference from Example 1 is that the molar ratios of glacial acetic acid and N,N-dimethylacetamide are different, as follows.

[0044] first step:

[0045] Add 0.3mol of aniline, 0.3mol of ammonium chloride, 0.15mol of glacial acetic acid, 0.45mol of N,N-dimethylacetamide and 0.24mol of dicyclohexylcarbodiimide into a round-bottomed flask, install an air condenser, Stir and heat up to 120°C, and reflux for 3 hours. After the reaction is complete, stop heating and cool to room temperature naturally.

[0046] Step two:

[0047] Add ice water to the reaction solution in the first step, let it stand still, and when no solid precipitates out, filter it with suction, continue cooling the filtrate to below 0°C, and filter it with suction after the solid is precipitated again, and filter the solid obtained by suction filtration twice Combined, washed with water, and dried to obtain white needle crystals with a yield of 98.7%.

Embodiment 3

[0049] The main difference from Example 1 is that the molar ratios of glacial acetic acid and N,N-dimethylacetamide are different, as follows.

[0050] first step:

[0051] Add 0.3mol of aniline, 0.3mol of ammonium chloride, 0.12mol of glacial acetic acid, 0.48mol of N,N-dimethylacetamide and 0.24mol of dicyclohexylcarbodiimide into a round bottom flask, and install an air condenser, Stir and heat up to 120°C, and reflux for 3 hours. After the reaction is complete, stop heating and cool to room temperature naturally.

[0052] Step two:

[0053] Add ice water to the reaction liquid in the first step, let it stand still, and when no solid precipitates out, filter it with suction, continue cooling the filtrate to below 0°C, and filter it with suction after the solid is precipitated again, and filter the solid obtained by suction filtration twice Combined, washed with water and dried to obtain white needle crystals with a yield of 98.1%.

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PUM

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Abstract

The invention provides a preparation method of acetanilide. The preparation method of acetanilide includes the steps of: mixing aniline, an acetylation reagent, a dehydrating agent and a catalyst evenly, then performing heating to 100-120DEG C, and carrying out reflux reaction for 3-4h at the temperature, then performing cooling to precipitate the product. Specifically, the acetylation reagent isa mixture of glacial acetic acid and N, N-dimethylacetamide mixed in a mole ratio of 1:2-4, the dehydrating agent is dicyclohexylcarbodiimide, and the catalyst is sodium amide and / or ammonium chloride. Compared with the prior art, by changing the type of the acetylation reagent, and adding the dehydrating agent and the catalyst, the yield of acetanilide is increased and can reach 98% or more.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a preparation method of acetanilide. Background technique [0002] Acetanilide is the raw material of sulfa drugs, which can be used as analgesic, antipyretic and antiseptic. Acetanilide is also used to manufacture dye intermediates such as p-nitroacetanilide, p-nitroaniline, p-phenylenediamine and para-ester. It was widely used in the manufacture of acetaminophensulfonyl chloride during World War II. Acetanilide is also used in the manufacture of thioacetamide. In industry, it can be used as a rubber vulcanization accelerator, a stabilizer for cellulosic coatings, a stabilizer for hydrogen peroxide, and for the synthesis of camphor, etc. Therefore, the synthesis technique of acetanilide is of great significance in practical application. [0003] Bibliographical reports, commonly used acetanilide synthetic method has following several: (1) aniline and excess glacial acetic ac...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C231/02C07C233/07
CPCC07C231/02C07C233/07
Inventor 闫玲玲蔡红新徐周庆王元王书擘
Owner 新乡市锦源化工有限公司
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