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A kind of method for preparing isohexitol

A technology for isohexitol and base hexitol, applied in the field of preparing isohexitol, can solve the problems of aggravated by-product generation, corrosiveness of reaction medium, harsh conditions, etc., achieves strong industrial application significance, low equipment requirements, and easy separation Effect

Active Publication Date: 2020-01-10
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the hydrated ZnCl of sorbitol in the molten state 2 Selective dehydration can be achieved in the medium to prepare isosorbide with high yield, but the method exists ZnCl 2 The medium is highly corrosive to the equipment, difficult to recycle, and the product is not easy to separate, etc.
[0007] In summary, the main problems remaining in the preparation process of isohexitol are as follows: (1) the solvent-free method needs to maintain a high degree of vacuum, which requires high technology and equipment, and it is difficult to maintain an industrial scale; or (2) strong inorganic acids such as sulfuric acid are used as catalysts A large amount of waste acid is produced, which is highly corrosive to equipment, and the catalyst is not easy to separate and reuse from the reaction system; or (3) the water solvent method requires high temperature, harsh conditions, high requirements on equipment, and high temperature will aggravate the formation of by-products , resulting in a low yield of the target product isohexitol; (4) the reaction medium is corrosive and difficult to recycle; or the selectivity of isohexitol is not high

Method used

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  • A kind of method for preparing isohexitol
  • A kind of method for preparing isohexitol
  • A kind of method for preparing isohexitol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Example 1: Solid acid catalyzed dehydration of bio-based hexitol in a single solvent to prepare isohexitol

[0022] Add the dehydration catalyst, bio-based hexitol and solvent into a reaction kettle equipped with a temperature control device and magnetic stirring, close the reactor, and react with magnetic stirring at a certain temperature for a period of time. After the reaction was completed, it was cooled to room temperature, and quantitative analysis of the product was carried out by gas chromatography internal standard method and high performance liquid chromatography (HPLC) external standard method, expressed in mole percent (mol%). The specific implementation conditions and results are shown in Table 1.

[0023] Table 1 Solid acid-catalyzed dehydration of bio-based hexitol to isohexitol in a single solvent.

[0024]

[0025]

[0026] [1]: The catalysts cited in the above examples are: A-70——acidic cation exchange resin Amberlyst-70; HPW, HSiW——Keggin type ...

Embodiment 2

[0029] Embodiment 2: Solid acid catalyzed dehydration of sorbitol in two-component solvent to prepare isosorbide

[0030] Add the dehydration catalyst, sorbitol and solvent into a reaction kettle equipped with a temperature control device and magnetic stirring, close the reactor, stir magnetically at 150°C for 180 minutes, and then cool to room temperature. Wherein, the mass ratio of catalyst and sorbitol is 0.2:1, and the molar ratio of mixed solvent and sorbitol is 40:1. Quantitative analysis of the product was carried out by gas chromatography internal standard method and high performance liquid chromatography (HPLC) external standard method, expressed in mole percent (mol%). The specific implementation conditions and results are shown in Table 2.

[0031] Table 2 Preparation of isosorbide from solid acid-catalyzed dehydration of sorbitol in two-component solvent.

[0032]

[0033] [1]: The catalysts cited in the above examples are: A-70——acidic cation exchange resin A...

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Abstract

The invention discloses a method for preparing isohexitol. The method comprises: contacting bio-based hexitol with a solvent and a dehydration solid acid catalyst under dehydration catalytic conditions to prepare isohexitol with high efficiency and high selectivity; Wherein, the solvent is one or a mixture of two selected from esters, ketones, ethers and hydrocarbons. The method is particularly suitable for the dehydration reaction of sorbitol and mannitol, and the yield of isohexitol is as high as 90%. The technical scheme of the invention has the advantages of simple operation, mild conditions, low requirements on equipment, environmental friendliness, easy separation and purification of products, and the like.

Description

technical field [0001] The invention relates to a method for preparing isohexitol, especially a method for preparing isohexitol from hexitol. Background technique [0002] With the increasing shortage of fossil resources and the intensification of environmental problems, catalytic conversion of biomass renewable resources to obtain high value-added chemicals and biofuels has become one of the important strategies for the sustainable development of energy and resources. [0003] As an important platform compound for biomass conversion, hexitols can be converted into isohexitols with diverse functions through two intramolecular dehydration due to their inherent polyhydric structure characteristics. In particular, sorbitol, which is produced from a wide range of sugars containing glucose units, such as sucrose, starch, and cellulose, undergoes secondary dehydration to generate isosorbide, a key bio-based platform compound. Based on the characteristics of functional dihydric hy...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D493/04
CPCC07D493/04
Inventor 车鹏华徐杰路芳高进司晓琴苗虹聂鑫
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI