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A kind of preparation method of low yellowness diether diphthalimide

A technology of diphthalimide and phthalimide, which is applied in the field of preparation of diether diphthalimide with low yellowness, can solve the problem of yellowish color, easy oxidation and yellowing of diether diphthalimide products, etc. The problem is that the preparation process is simple, it is not easy to oxidize and turn yellow, and the color is light.

Active Publication Date: 2021-02-02
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to provide a kind of preparation method of low yellowness diether diphthalimide, adopts methyl chloride / ethyl chloride gas to react with residual phenolic hydroxyl group / phenate terminal group to generate stable alkyl, solves the problem in In the process of existing production technology, the color of the diether diphthalimide product turns yellow, and the problem that it is easy to oxidize and turn yellow

Method used

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  • A kind of preparation method of low yellowness diether diphthalimide
  • A kind of preparation method of low yellowness diether diphthalimide
  • A kind of preparation method of low yellowness diether diphthalimide

Examples

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Embodiment 1

[0035] Add 150 mL of o-xylene in a 500 mL three-necked flask, start stirring, feed nitrogen, then add bisphenol A (22.8 g, 0.1 mol) and sodium hydroxide (8.8 g, 0.22 mol) in sequence, start heating, and the temperature of the system rises to After 100°C, continue to keep warm for 2 hours, then raise the temperature to the system reflux (about 143°C), separate the water for 2-3 hours until there is no water drop in the water separator, continue to heat and evaporate the o-xylene solvent, turn off the heat and continue to blow dry with nitrogen to powder, after cooling down to normal temperature, add N-methyl-4-nitrophthalimide (4-NPI, 41.2g, 0.2mol, purchased from Wuhan Yuancheng Technology), N,N'-di Methylacetamide (DMAC) 140mL, heated to 150°C, reacted for 3h, then turned off the heating and cooled to 100°C, then passed in ethyl chloride gas for 20min, kept the stirring speed of the system at 300RPM, and the ventilation rate at 2mL / s. The reaction solution was cooled to room ...

Embodiment 2

[0037] Add 150mL of toluene into a 500mL three-neck flask, start the stirring, blow in nitrogen, then add bisphenol A (22.8g, 0.1mol) and potassium hydroxide (12.3g, 0.22mol) in sequence, turn on the heating, and the temperature of the system rises to 80°C Continue to keep warm for 3 hours, then raise the temperature to the reflux of the system (about 110°C), separate the water for 2 to 3 hours until there is no drop of water in the water separator, continue to heat and evaporate the toluene solvent, turn off the heating and continue to blow dry with nitrogen until it becomes powdery. After cooling down to room temperature, add N-methyl-4-nitrophthalimide (4-NPI, 41.2g, 0.2mol), DMF 140mL, heat up to 140°C, react for 5h, then cool to 120°C Feed into methyl chloride gas for 30min, keep the stirring speed of the system at 400RPM, and the ventilation rate at 3mL / s, then separate out the reaction solution, wash and dry it several times (the processing method is the same as that of ...

Embodiment 3

[0039]Add 300mL o-xylene into a 1000mL three-neck flask, start stirring, feed nitrogen, then add bisphenol S (50.0g, 0.2mol) and sodium hydroxide (17.6g, 0.44mol) in sequence, start heating, and the system is heated to 90 Keep warm at ℃ for 2.5 hours, raise the temperature to reflux (144℃), separate the water for 3-4 hours until no water drops fall in the water separator, continue to heat and evaporate the o-xylene to dryness, dry the powder with nitrogen, add dimethyl sulfoxide after cooling down to room temperature 280mL, N-methyl-4-bromophthalimide (96.0g, 0.4mol, TCI reagent), heated to 150°C, reacted for 6h, then cooled to 110°C, passed through ethyl chloride gas for 1h, Keep the stirring speed of the system at 200RPM, the ventilation rate at 5mL / s, and then stop the reaction. The treatment method is the same as in Example 1 to obtain 103.5g of diether diphthalimide powder, with a yield of 91.1%, a purity of 99.90%, and a yellowness b value of 4.90 .

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Abstract

The invention relates to a preparation method of a low-yellowness diether diphthalimide, which comprises the following steps: (A) reacting diphenol with a strong base in a non-polar solvent to prepare a diphenolate; (B) the product of step A Carrying out nucleophilic reaction with phthalimide in a polar aprotic solvent; (C) After the reaction in step (B), injecting methyl chloride and / or ethyl chloride gas into the system to obtain diether diphthalimide. The present invention uses methyl chloride and / or ethyl chloride gas to react with residual phenolic hydroxyl groups / phenate end groups to generate stable alkyl groups, which solves the problem of yellowing of the diether diphthalimide product in the prior production technology process, The problem of easy oxidation and yellowing.

Description

technical field [0001] The invention relates to a preparation method of a low-yellowness diether diphthalimide, which belongs to the technical field of fine chemical synthesis. Background technique [0002] Diether diphthalimide is an important intermediate for the synthesis of polyetherimide materials, and its structure is as follows: The substance can be further prepared by hydrolysis, acidification, and dehydration to prepare dianhydride monomers. Dianhydride and diamine are further polymerized to form polyetherimide, which is the most important intermediate in the synthesis of polyetherimide. [0003] Many documents have reported the preparation method of diether diphthalimide (see published patents: CN1336364A; CN1634904A; US4017511A, US4247464A). The existing technology is as follows: first react diphenol with a strong base to generate diphenolate, and then prepare diether diphthalimide through nucleophilic reaction in a polar aprotic solvent. The inventors of the ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D209/48
CPCC07D209/48
Inventor 屈亚青张鑫陈海波
Owner WANHUA CHEM GRP CO LTD