Preparation method of 3-nitrophthalic anhydride

A technology of nitrophthalic anhydride and nitrophthalic acid, which is applied in the field of preparation of 3-nitrophthalic anhydride, can solve the problems of low output, large manpower, material resources and high cost, and achieve The effect of low cost, high yield and simple process

Inactive Publication Date: 2019-03-29
JIANGSU YONGAN CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

At present, the raw material for synthesizing 3-nitrophthalic anhydride is phthalic anhydride, and at the same time, the by-product 4-nitrophthalic an

Method used

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  • Preparation method of 3-nitrophthalic anhydride

Examples

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Effect test

Embodiment 1

[0016] The preparation method of 3-nitrophthalic anhydride: 212 grams of 3-nitrophthalic acid is placed in the reaction solvent, the reaction solvent is 300 grams of toluene and 50 grams of acetic acid, then add 6 grams of p-toluenesulfonic acid, Raise the temperature to 100-150°C and react for 4-12 hours, take a sample and detect by HPLC that the 3-nitrophthalic acid content is less than 1%, and stop heating; the obtained substance is removed under the condition of negative pressure -0.08- -0.098Mpa toluene and acetic acid , p-toluenesulfonic acid to obtain 184.5 grams of 3-nitrophthalic anhydride, with a content of 98% and a yield of 95.1%.

Embodiment 2

[0018] The preparation method of 3-nitrophthalic anhydride: 212 grams of 3-nitrophthalic acid is placed in the reaction solvent, the reaction solvent is 400 grams of toluene and 100 grams of acetic acid, then add 4 grams of p-toluenesulfonic acid, Raise the temperature to 100-150°C and react for 4-12 hours, take a sample and detect by HPLC that the 3-nitrophthalic acid content is less than 1%, and stop heating; the obtained substance is removed under the condition of negative pressure -0.08- -0.098Mpa toluene and acetic acid , p-toluenesulfonic acid to obtain 182 grams of 3-nitrophthalic anhydride, with a content of 98% and a yield of 93.8%.

Embodiment 3

[0020] The preparation method of 3-nitrophthalic anhydride: 212 grams of 3-nitrophthalic acid is placed in the reaction solvent, the reaction solvent is 350 grams of toluene and 55 grams of acetic acid, then add 5 grams of p-toluenesulfonic acid, 5 grams of tetrabutylammonium bromide, heat up to 100-150°C and react for 4-12 hours, take a sample and stop heating when the content of 3-nitrophthalic acid is less than 1% by HPLC; Toluene, acetic acid and p-toluenesulfonic acid were removed under the condition of 0.098Mpa to obtain 186 grams of 3-nitrophthalic anhydride with a content of 97.5% and a yield of 95.8%.

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Abstract

The invention relates to a preparation method of 3-nitrophthalic anhydride. The method includes the following steps: placing 3-nitrophthalic acid in a reaction solvent, adding a catalyst, and heatingfor reaction; and removing the reaction solvent and the catalyst from an obtained substance under negative pressure to obtain the 3-nitrophthalic anhydride. In the preparation method, the 3-nitrophthalic acid raw material can be easily obtained, the 3-nitrophthalic anhydride is synthesized by direct catalytic dehydration in one step, and the preparation method has the advantages of simple process,low cost, high yield and no by-products.

Description

technical field [0001] The invention belongs to the field of organic synthesis intermediates, and in particular relates to a preparation method of 3-nitrophthalic anhydride. Background technique [0002] 3-Nitrophthalic anhydride is an important intermediate in organic synthesis, widely used in the synthesis of dyes, medicines, fluorescent agents, etc. 3-Nitrophthalic anhydride is a downstream product of 3-nitrophthalic acid, and 3-nitrophthalic anhydride is an intermediate of cyclic ester fluoride, pyrimifluben, and fluorescamine. At present, the raw material for synthesizing 3-nitrophthalic anhydride is phthalic anhydride, and at the same time, the by-product 4-nitrophthalic anhydride is obtained. The output is low, and it will cost a lot of manpower and material resources to separate in the later stage, and the cost is high. . Contents of the invention [0003] The present invention overcomes the deficiencies in the prior art and is to provide a method for preparing 3...

Claims

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Application Information

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IPC IPC(8): C07D307/89
CPCC07D307/89
Inventor 陈夕鹏赵坚强王晓军杜开云
Owner JIANGSU YONGAN CHEM CO LTD
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