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A kind of preparation method of n-methyl-4-nitrophthalimide

A technology of nitrophthalimide and methylphthalimide, which is applied in the field of preparation of N-methyl-4-nitrophthalimide, can solve equipment and Operation hazards, environmental pollution, low yield and other problems, to avoid environmental and human hazards, promote the reaction rate, improve yield and purity effects

Active Publication Date: 2021-05-14
山东省鄄城县方源轴承化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Because this method adds fuming concentrated nitric acid at a lower temperature, N-methyl-4-nitrophthalimide will be precipitated and exothermic, resulting in a lower yield of about 80%.
In addition, in this process, corrosive concentrated sulfuric acid and fuming nitric acid are used, which will cause harm to equipment and operations, and a large amount of acidic wastewater generated during the production process will not only pollute the environment, but also increase treatment costs

Method used

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  • A kind of preparation method of n-methyl-4-nitrophthalimide
  • A kind of preparation method of n-methyl-4-nitrophthalimide

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0072] Embodiment 1 of the present invention provides a kind of preparation method of N-methyl-4-nitrophthalimide, comprises the following steps:

[0073] Preparation of nitrating agent: mix potassium nitrate and concentrated sulfuric acid at 0°C, and the molar ratio of ammonium nitrate and concentrated sulfuric acid is 1:1.8 to generate nitrating agent;

[0074] Preparation of N-methylphthalimide: add methylamine-ethanol solution and phthalic anhydride to toluene, the molar ratio of methylamine and phthalic anhydride is 1:1, heat to reflux for 3 hours, dry, and crystallize by ethanol cooling to obtain N-methylphthalimide;

[0075] Preparation of N-methyl-4-nitrophthalimide: add nitrating agent to N-methylphthalimide at -5°C, react at 40°C for 4 hours, and extract with extraction solvent, Drying produces N-methyl-4-nitrophthalimide.

[0076] The extraction solvent is ethyl acetate and dichloromethane in a weight ratio of 1:0.6, and the weight ratio of the extraction solvent ...

Embodiment 2

[0078] Embodiment 1 of the present invention provides a kind of preparation method of N-methyl-4-nitrophthalimide, comprises the following steps:

[0079] Preparation of nitrating agent: mix magnesium nitrate and concentrated sulfuric acid at 10°C, and the molar ratio of potassium nitrate and concentrated sulfuric acid is 1:2.2 to generate nitrating agent;

[0080] Preparation of N-methylphthalimide: add methylamine-ethanol solution and phthalic anhydride to toluene, the molar ratio of methylamine and phthalic anhydride is 2:1, heat to reflux for 2h, dry, and crystallize by ethanol cooling to obtain N-methylphthalimide;

[0081] Preparation of N-methyl-4-nitrophthalimide: Add nitrating agent to N-methylphthalimide at 5°C, react at 50°C for 3h, extract with extraction solvent, and dry , Generate N-methyl-4-nitrophthalimide.

[0082] The extraction solvent is ethyl acetate and dichloromethane in a weight ratio of 1:0.8, and the weight ratio of the extraction solvent to N-methy...

Embodiment 3

[0084] Embodiment 3 of the present invention provides a kind of preparation method of N-methyl-4-nitrophthalimide, comprises the following steps:

[0085] Preparation of nitrating agent: mix ammonium nitrate and concentrated sulfuric acid at 5°C, the molar ratio of ammonium nitrate and concentrated sulfuric acid is 1:2, and generate nitrating agent;

[0086] Preparation of N-methylphthalimide: add methylamine-ethanol solution and phthalic anhydride to toluene, the molar ratio of methylamine and phthalic anhydride is 1.5:1, heat to reflux for 2.5h, dry, and ethanol cooling crystallization, Obtain N-methylphthalimide;

[0087] Preparation of N-methyl-4-nitrophthalimide: Add nitrating agent to N-methylphthalimide at 0°C, react at 45°C for 3.5h, and extract with extraction solvent, Drying produces N-methyl-4-nitrophthalimide.

[0088] The extraction solvent is ethyl acetate and dichloromethane in a weight ratio of 1:0.7, and the weight ratio of the extraction solvent to N-methyl...

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Abstract

The present invention relates to the technical field of organic synthesis technology, more specifically to a kind of preparation method of N-methyl-4-nitrophthalimide. The method comprises the following steps: preparation of nitrating agent: mixing nitrate and concentrated sulfuric acid to generate nitrating agent; preparation of N-methylphthalimide: adding methylamine and phthalic anhydride to a solvent, and heating under reflux to obtain N-methyl phthalimide Phthalimide; N-methyl-4-nitrophthalimide Preparation: Adding a nitrating agent to N-methylphthalimide reacts to generate N-methyl-4- Nitrophthalimide. The present invention prepares the nitrating agent by using nitrate and concentrated sulfuric acid at a lower temperature, avoiding the environmental and human hazards caused by fuming nitric acid, and after the nitrating agent of the present invention undergoes nitration reaction, the remaining nitration agent can be extracted by extraction It can also be used as a by-product by adding additives to obtain nitrate or sulfate precipitation, such as ammonium nitrate and ammonium sulfate, which can be used as fertilizers to achieve a green cycle reaction.

Description

technical field [0001] The invention relates to the technical field of organic synthesis technology, more specifically, the invention relates to a preparation method of N-methyl-4-nitrophthalimide. Background technique [0002] N-methyl-4-nitrophthalimide is an important chemical intermediate, which can be used to prepare various monomers of polyimide dianhydride, benzimidazole and its derivatives, and can also be used as a fluorescent probe. The preparation method of preparing N-methylphthalimide mainly contains two kinds at present: a kind of is to prepare (yield is 77%) with the alkylation reaction preparation (yield is 77%) of potassium salt of phthalimide and methyl iodide , or use the potassium salt diimide of phthalimide and methyl p-toluenesulfonate for alkylation; the other method is based on the ring-opening reaction of phthalic anhydride and gas or liquid methylamine, and then undergoes The ring-closing reaction of phthalimide, and finally N-methylphthalimide is...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D209/48
CPCC07D209/48
Inventor 李治张洪源张何纪
Owner 山东省鄄城县方源轴承化工有限公司