Method for preparing di-(N-methyl phthalimide) ether

Abstract

The invention discloses a method for preparing di-(N-methyl phthalimide) ether. The method comprises the following steps: firstly, one or two types of non-polar solvents and one kind of polar non-protonic solvent are mixed, the non-polar solvents are steamed out, then the mixed solvent reaches a certain proportion, N-methyl-4-nitryl phthalimide carries out self condensation reaction under the catalysis of one or two catalysts and normal pressure in the mixed solvent, heating and reflowing are conducted for 2 to 8 hours, and then the solvent is recovered, water is added, product is precipitatedafter cooling, and finally, tawny di-(N-methyl phthalimide) ether is obtained after filtering, washing and drying, the yield rate is 68 to 85 percent, and the melting point is 272.6 to 273 DEG C. Thecatalyst is organic acid salt and carbonate of organic acid salt of alkali metals and alkali-earth metals.

Description

The preparation method of bis-(N-methylphthalimide) ether technical field The invention relates to a preparation of organic matter, in particular to a preparation method of bis-(N-methylphthalimide) ether. Background technique Bis(N-methylphthalimide) ether is a fine organic product with high added value. ) is the most important intermediate. Monoether anhydride is one of the important monomers of new special engineering plastics polyimide, polyetherimide, polyesterimide, polyamideimide, polymaleimide, polyaramide and other high temperature resistant resins . It can also be used as a cross-linking agent for synthetic polymer materials such as high-performance heat-resistant epoxy resin and polyurethane. Monoether anhydride polyimide has outstanding mechanical properties, electrical properties, and radiation resistance, and can be used for a long time in the range of 180 ° C to 230 ° C. Due to the introduction of flexible ether bonds in the polyimide main chain structur...

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Problems solved by technology

There is also a method of composite catalyst mixed with gas phase white carbon black, carbonate and phase transfer catalyst, but it is difficult to widely apply in industry to filter the catalyst in a polar aprotic solvent with high viscosity

In addition, in the presence of a binary inorganic catalyst sodium nitrite and potassium fluoride and a third-dimensional phase transfer catalyst tetrabutylammonium bromide, a white condensation reaction is carried out to prepare bis (N-methylphthalimide) ether, However, this method brings a large amount of inorganic salts into the water, making it difficult to treat the wastewater and causing an increase in environmental protection costs.

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