Purification method of N-methyl pyrrolidone

The technology of a methyl pyrrolidone and a purification method is applied in the production field of heterocyclic compounds, and can solve the problems of low purity and yield of N-methyl pyrrolidone, and achieve the effects of strong selectivity, strong solubility and high boiling point

Inactive Publication Date: 2009-08-19
MAIQI CHEM CO LTD
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  • Abstract
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Problems solved by technology

[0002] The traditional purification method of N-methylpyrrolidone, the purity and yield o

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  • Purification method of N-methyl pyrrolidone

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[0007] The invention is to add the strong alkali and weak sodium salt of the water blocking agent to the crude product at 0.1-2% of the crude product, and then continuously feed it into the three-tower rectification system of the deamination tower, the dehydration tower, and the product tower. The high-quality Packing, three-column continuous vacuum distillation, the pressure is controlled between -80 to -95kPa, the advanced distillation operation method is adopted according to the principle of optimal reflux separation effect, and the reflux ratio of 1.5-3 is used for product extraction, which effectively controls The content of impurities such as metal ions improves the yield and purity of the product; the content of impurities such as metal ions is effectively controlled. The product purity is ≥99.9%, the moisture content is ≤100ppm, and the yield of N-methylpyrrolidone is more than 99%.

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Abstract

The invention relates to a method for purifying N-methylpyrrolidone, which is a method for producing a heterocyclic compound. The method comprises the following steps: adding a water repellent agent accounting for 0.1 to 2 percent of a crude product into crude product solution, and then continuously throwing the mixture into a three-tower combined rectifying system. By adopting good-quality stuffing and three-tower continuous pressure reduced rectification, adopting an advanced rectifying operation method according to the optimal principle of reflux separation effect, and adopting a reflux ratio of 1.5 to 3 to extract a product, the method effectively controls the contents of impurities such as metal ions and the like.

Description

[0001] One, the present invention relates to the production method of heterocyclic compound, especially a kind of purification method of N-methylpyrrolidone. 2. Background technology: [0002] In the traditional purification method of N-methylpyrrolidone, the purity and yield of the target product N-methylpyrrolidone are relatively low, and the moisture and impurities are relatively high. 3. Contents of the invention: [0003] The purpose of the present invention is to provide a kind of purification method of N-methylpyrrolidone suitable for industrialized production with high product quality, low water content and stable quality. It solves the problems existing in other technologies, and the purpose of the present invention is achieved in this way, it is to add the sodium salt of the strong base and weak acid of the water blocking agent into the crude product liquid at 0.1-2% of the crude product liquid, and then continuously inject the deamination The rectification system ...

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Application Information

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IPC IPC(8): C07D207/267B01D3/10
Inventor 宋国全肖强杨理
Owner MAIQI CHEM CO LTD
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