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Method of synthesizing hexanolactam by cyclohexanone and ionic liquid type hydroxylamine salt by one step

A technology of ionic liquid and caprolactam, which is applied in the preparation of lactam, chemical instruments and methods, and the production of bulk chemicals, can solve problems such as equipment corrosion, unfriendly environment, and complicated routes, and achieve no corrosion of equipment and reduce production costs , The effect of simple process

Active Publication Date: 2014-10-08
HEBEI UNIV OF TECH
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  • Abstract
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  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is: in view of the complex route in the current production process of caprolactam, and the equipment corrosion caused by the use of inorganic acid hydroxylamine salt, the environment is not friendly, etc., and at the same time realize the one-step clean synthesis of caprolactam, we use self-made ionic liquid Type hydroxylamine salt (expressed as (NH 2 Oh) 2 ·ILs) (Chinese patent, application number 201310481404.2) replaces inorganic acid hydroxylamine salt, uses zinc salt as a catalyst, and realizes one-step clean synthesis of caprolactam under solvent-free conditions. The reaction process is as follows:

Method used

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  • Method of synthesizing hexanolactam by cyclohexanone and ionic liquid type hydroxylamine salt by one step
  • Method of synthesizing hexanolactam by cyclohexanone and ionic liquid type hydroxylamine salt by one step

Examples

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Embodiment 1

[0025] 1-sulfobutyl-3-methylimidazolium bisulfate ionic liquid type hydroxylamine salt is synthesized according to the method of Chinese patent, application number 201310481404.2:

[0026] The first step, the preparation of free hydroxylamine aqueous solution (US5266290, 1993): Weigh 41.0g of hydroxylamine sulfate (0.5mol in terms of hydroxylamine) and dissolve it in 100ml of distilled water (5.56mol), and place the above-mentioned hydroxylamine sulfate aqueous solution at a low temperature of -5°C In a constant temperature reactor, add dropwise 40 g of 50% NaOH solution with stirring (wherein, the alkali is 0.5 mol in terms of hydroxide radicals, and the water is 1.11 mol); after the addition, continue to stir for 0.1 h, filter and separate the reaction Liquid, get filtrate 100ml, filter cake washes with 40ml distilled water, merges filtrate and lotion and adds up to 140ml; In above-mentioned combined filtrate and lotion, add stabilizer ascorbic acid 0.105g (weight percentage ...

Embodiment 2

[0030] Add cyclohexanone (1 mmol), the ionic liquid hydroxylamine salt (2 mmol) obtained in Example 1 and the ground zinc chloride catalyst (2 mmol) into a 10 ml single-necked flask, seal the reaction system, and stir evenly at room temperature. Then react at a temperature of 150° C. for 1.5 h. The reaction product was extracted twice with dichloromethane, the extracts were combined, and the extracts were directly analyzed qualitatively and quantitatively by gas chromatography. The reaction results showed that the conversion rate of cyclohexanone was 98.6%, and the selectivity of caprolactam was 76.1%.

Embodiment 3

[0032] The steps are the same as in Example 2, except that the catalyst added is zinc oxide (2 mmol), and the reaction result is that the conversion rate of cyclohexanone is 98.0%, and the selectivity of caprolactam is 4.7%.

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Abstract

The invention relates to a method of directly synthesizing hexanolactam by cyclohexanone and ionic liquid type hydroxylamine salt. The method comprises the following steps: adding cyclohexanone, ionic liquid type hydroxylamine salt and a zinc salt catalyst into a reactor and uniformly stirring at room temperature; and then, carrying out a reaction at 140-160 DEG C for 0.5-2.5 hours in a closed system to obtain the product hexanolactam, wherein the material molar ratio of cyclohexanone to ionic liquid type hydroxylamine salt to zinc salt catalyst is 1 to (1-2) to (1.5-3), and the ionic liquid type hydroxylamine salt is 1-sulfobutyl-3-methylimidazole hydrosulfate ionic liquid type hydroxylamine salt. The method provided by the invention integrates oximation of cyclohexanone and rearrangement of cyclohexanone-oxime in a same reactor, so that the reaction flow is shortened and the production cost of hexanolactam is remarkably saved. The method has the advantages of no corrosion to equipment, environment-friendliness and the like and meets the requirements on green chemistry. The conversion ratio of cyclohexanone and the selectivity of hexanolactam are high, and the maximum can be up to 100% and 91.0% respectively.

Description

technical field [0001] The invention relates to the synthesis of organic chemical products, in particular to a method for synthesizing caprolactam in one step from cyclohexanone and ionic liquid hydroxylamine salt. Background technique [0002] Caprolactam is an important organic chemical intermediate, mainly used in the production of nylon 6 fiber, engineering plastics, food packaging film and pharmaceutical raw materials (Fine Chemical Raw Materials and Intermediates, 2011(1): 38-43). Industrially, caprolactam is mainly prepared by the cyclohexanone-hydroxylamine method, that is, cyclohexanone reacts with hydroxylamine salt to generate cyclohexanone oxime, and cyclohexanone oxime is then catalyzed by concentrated sulfuric acid or oleum through Beckmann rearrangement to obtain caprolactam. However, this process has disadvantages such as complex process route, equipment corrosion, unfriendly environment, and a large amount of low-value ammonium sulfate by-product (Jiangxi Ch...

Claims

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Application Information

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IPC IPC(8): C07D201/06C07D223/10
CPCY02P20/52C07D201/06C07D223/10
Inventor 王延吉李志会张东升齐旭东徐元媛杨秋生赵新强
Owner HEBEI UNIV OF TECH