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Method for preparing high-purity p-chloro-m-nitroacetoacetanilide

A technology of nitroacetoacetanilide and nitroaniline is applied in the field of preparation of pesticide intermediates, can solve problems such as poor product purity, recrystallization, low yield, etc. Effect

Active Publication Date: 2008-05-14
SHANDONG JINCHENG PHARMACEUTICAL GROUP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The technical problem to be solved by the present invention is to provide a kind of preparation method of high-purity p-chloro-o-nitroacetoacetanilide, to overcome the ubiquitous problems of poor product purity, low yield and need for recrystallization in the prior art

Method used

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  • Method for preparing high-purity p-chloro-m-nitroacetoacetanilide

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Add mixed solvent [toluene: dichloromethane (weight ratio) = 1: 3] 2500kg, N, N, N', N'-tetramethylethylenediamine 20kg in the reaction kettle, start stirring, add p-chloro-o-nitrate Aniline 450kg; warm up to 60°C, start to add 229kg of DK (diketene) dropwise, and control the dropping time for 1h; continue to keep warm for 1h after dropping, and control the temperature at 60°C; Wash with mixed solvents and dry. Obtain product 605kg, yield 90.42%.

[0023] Mother liquor cycle times

[0024] The obtained mother liquor is reused in the following 10 reaction cycles without additional catalyst, and an average of 649.4 kg of product can be obtained with a yield of 97.06%.

Embodiment 2

[0026] Add 1500kg of mixed solvent [water:ethanol (weight ratio)=0.9:0.1], 0.45kg of 2-picoline to the reaction kettle, start stirring, then drop in 450kg of p-chloro-o-nitroaniline; heat up to 100°C, start dripping Add 260kg of DK, and control the dropping time to 0.5h; after the dropping, continue to keep warm for 0.5h; after the reaction, cool down to 5°C, filter, wash the filter cake with a mixed solvent, and dry. Obtain product 535kg, yield 80%.

Embodiment 3

[0028] Add mixed solvent [benzene: chloroform (weight ratio) = 0.1: 0.9] 4500kg, diethylamine 12kg in the reactor, start stirring, add p-chloro-o-nitroaniline 450kg; Warm up to 15°C, drop DK 245kg, control The dropwise addition time is 4h; after the dropwise addition, continue the heat preservation reaction for 6h; after the reaction is completed, the temperature is lowered to 0°C, filtered, and the filter cake is washed with a mixed solvent and dried. Obtain product 595kg, yield 88.93%.

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Abstract

The invention discloses a method for preparing high-purity p-chloro-m-nitroacetoacetanilide, in which adopts the technical proposal that p-chloro-o-nitroaniline and catalyst are added in mixed solvent at 15 to 100 DEG C, and then diketene is dripped within 0.5 to 4 hours for reaction for 0.5 to 6 hours to prepare the p-chloro-m-nitroacetoacetanilide, wherein the mixed solvent can be either the solvent composed of two or more materials among water, acetone, tetrahydrofuran, acetonitrile, ethanol, toluene, benzene, isopropyl alcohol, chloroform, dichloromethane, ethyl acetate, butyl acetate and methyl acetate or circulating mother liquor. The circulating mother liquor can be recycled for as many as 10 times and extra catalyst is not needed with the purity of products exceeding 99% and the yield reaching 97%. The invention has the advantages of simple and controllable process, no need of recrystallization and high purity.

Description

technical field [0001] The present invention relates to a kind of preparation method of pesticide intermediate, more specifically relate to a kind of method of preparation p-chloro-o-nitroacetoacetanilide. Background technique [0002] p-Chloro-Nitroacetoacetanilide is a light yellow crystal, which is mainly used as an intermediate in the synthesis of herbicides and drugs. [0003] US 4636562 discloses that p-chloro-o-nitroaniline is used as raw material and triethylamine is used as catalyst, and a mixed solution of diketene and benzene is added dropwise in reflux in benzene. After the reaction, the crude product was recrystallized with ethanol, and the product yield was 80%. The disadvantage of this process is that the product needs to be recrystallized, resulting in low product yield and increased production costs. [0004] GB 770263 discloses the synthesis of 2-nitro-4-chloroacetoacetanilide using water-insoluble primary aromatic amines and...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C235/74C07C231/04
Inventor 周文峰赵叶青卢言建郑军齐立海郭玉峰
Owner SHANDONG JINCHENG PHARMACEUTICAL GROUP CO LTD
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