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N-methyl-4-nitrophthalimide preparation method

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

Active Publication Date: 2019-11-12
山东省鄄城县方源轴承化工有限公司
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  • 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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Examples

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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 invention relates to the technical field of organic synthesis processes, particularly to a N-methyl-4-nitrophthalimide preparation method, which comprises: preparation of a nitrating agent: mixinga nitrate and concentrated sulfuric acid to form a nitrating agent; preparation of N-methylphthalimide: adding methylamine and phthalic anhydride to a solvent, and carrying out heating reflux to obtain N-methylphthalimide; and preparation of N-methyl-4-nitrophthalimide: adding the nitrating agent to the N-methylphthalimide, and carrying out a reaction to form N-methyl-4-nitrophthalimide. According to the present invention, the nitrating agent is prepared at a low temperature by using nitrate and concentrated sulfuric acid so as to avoid the harm of fuming nitric acid to environmental and human body; and after the nitrating reaction is performed with the nitrating agent, the remaining nitrating agent can be recycled by extraction, and can further be added with an auxiliary agent to obtainnitrate or sulfate precipitate as a by-product, wherein ammonium nitrate or ammonium sulfate, and the like can be used as fertilizers so as to achieve environmentally friendly circulation reactions.

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 Applications(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
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