- Method for preparing N, N, N
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The method comprises the following steps: (N) adding an excess of diisopropanolamine and an alkaline catalyst into a reaction kettle, then dropwise adding dimethyl adipate N, and preparing N, 1, N N (2): The temperature in the reaction kettle was decreased to the set temperature, and the neutralized acid was added dropwise or batchwise to the reaction kettle under a vacuum condition to neutralize excess diisopropanolamine, and dehydration was performed simultaneously. (3): After completion of the neutralization, a solvent was added to the reaction kettle, and the crystals were stirred and then filtered to separate the diisopropanolamine sulfate. The filtrate was separated off by distillation to give a high purity N, N, NTo the method, unreacted diisopropanolamine raw materials are separated through the high-amine ester, the preparation process is simple, the energy consumption is low, and the separated diisopropanolamine salt can be recycled as an industrial raw material.
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Paragraph 0018-0041
(2021/11/27)
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- Method for preparing beta-hydroxyalkylamide through extraction and purification
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The invention discloses a method for preparing beta-hydroxyalkylamide by extraction and purification, which comprises the following steps: (1) adding excessive dialkyl alcohol amine and a basic catalyst into a reaction kettle, and dropwisely adding dicarboxylic acid dialkyl ester to prepare a beta-hydroxyalkylamide crude product; (2) adding an extraction solvent into the beta-hydroxyalkylamide crude product, conducting extracting, stirring and standing to form an upper-layer liquid and a lower-layer liquid, and separating the upper-layer liquid from the lower-layer liquid; and (3) distilling the lower-layer liquid to separate the residual extraction solvent to obtain a beta-hydroxyalkylamide product, and distilling the upper-layer liquid, and recovering the extraction solvent and the dialkyl alcohol amine raw material. By utilizing the method, the reaction materials can be conveniently separated, and the beta-hydroxyalkylamide product with higher purity can be obtained.
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Paragraph 0019-0057; 0070-0081; 0085-0087
(2021/01/11)
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- Preparation method of N,N,N,N'-tetra(beta-hydroxypropyl)adipamide
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The invention discloses a preparation method of N,N,N,N'-tetra(beta-hydroxypropyl)adipamide, which includes steps of: 1) adding diisopropanol amine, in excessive amount, and an alkaline catalyst to areaction kettle, heating the reaction kettle to 100 +/- 5 DEG C, adding dimethyl adipate, and preparing a N,N,N,N'-tetra(beta-hydroxypropyl)adipamide crude product under vacuum; 2) cooling the N,N,N,N'-tetra(beta-hydroxypropyl)adipamide crude product to preset temperature and adding the dimethyl adipate, and stirring and crystallizing the product; 3) after the crystallization, adding a co-dispersant and fully stirring the product, and at crystalline temperature, performing positive pressure filtration on the crystal slurry to separate a filter cake and a filtrate, and drying the filter cake toobtain a high-purity product. The method can be used for preparing the high-purity N,N,N,N'-tetra(beta-hydroxypropyl)adipamide product at high yield. The solvent is high in boiling point and flash point; so that the crystalline process, compared with a conventional solvent system, is safe and environment-friendly.
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Paragraph 0014-0029
(2019/04/26)
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