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Synthetic method of 1,6-hexamethylene dicarbamate

A technology for the synthesis of butyl hexamethylene dicarbamate, which is applied to the preparation of carbamic acid derivatives, chemical instruments and methods, and the preparation of organic compounds. Catalytic effect is not good enough and other problems, to achieve a wide range of industrialization prospects, improve product yield and selectivity, the effect of low reaction temperature

Inactive Publication Date: 2016-02-03
王晓伟
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, the existing technology still has many defects such as expensive catalyst, insufficient catalytic effect, and high reaction temperature. These defects have caused problems such as low corporate profits and potential safety hazards for large-scale production.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] (1) Take 5mol n-butanol and place it in a reaction kettle, control the temperature at 50°C, slowly add a mixture of 2.4mol n-butyl carbamate and 1mol hexamethylenediamine to it while stirring;

[0017] (2) After stirring evenly, add 4.06g of catalyst 1-butyl-3-methylimidazole chloride to the reaction mixture, gradually heat up to 140°C, control the pressure at 1.5Mpa, and react for 10 hours;

[0018] (3) After the reaction was completed, the solvent was removed by rotary evaporation, and diethyl ether was added to precipitate a solid, which was filtered and washed with water to obtain butyl 1,6-hexamethylenedicarbamate with a yield of 65% and a purity of 87% by HPLC.

Embodiment 2

[0020] (1) Take 4mol n-butanol and place it in a reactor, control the temperature at 60°C, slowly add a mixture of 3mol n-butyl carbamate and 1mol hexamethylenediamine to it while stirring;

[0021] (2) After stirring evenly, add 5.8g of catalyst 1-butyl-3-methylimidazole chloride to the reaction mixture, gradually heat up to 160°C, control the pressure to 2.0Mpa, and react for 5 hours;

[0022] (3) After the reaction was completed, the solvent was removed by rotary evaporation, and diethyl ether was added to precipitate a solid, which was filtered and washed with water to obtain butyl 1,6-hexamethylenedicarbamate with a yield of 57% and a purity of 89% by HPLC.

Embodiment 3

[0024] (1) Take by weighing 4.5mol n-butanol and place it in a reactor, control the temperature at 50° C., slowly add a mixture of 2mol n-butyl carbamate and 1mol hexamethylenediamine to it while stirring;

[0025] (2) After stirring evenly, add 3.48g of catalyst 1-butyl-3-methylimidazole chloride to the reaction mixture, gradually heat up to 150°C, control the pressure to 1.8Mpa, and react for 8 hours;

[0026] (3) After the reaction was completed, the solvent was removed by rotary evaporation, and ether was added to precipitate a solid, which was filtered and washed with water to obtain butyl 1,6-hexamethylenedicarbamate with a yield of 61% and a purity of 85% by HPLC.

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PUM

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Abstract

The invention relates to a synthetic method of 1,6-hexamethylene dicarbamate. n-Butyl carbamate and hexamethylene diamine are used as raw materials, and imidazoles ion liquid replaces precious metals and is used as a catalyst. The catalytic reaction is highly efficient, and the green environmental protection characteristic of the chemical process is guaranteed; the synthetic method has the advantages of low reaction temperature and low pressure, meets the requirement of energy saving and emission reduction, and has a wide large-scale production prospect.

Description

technical field [0001] The invention relates to a method for synthesizing butyl 1,6-hexamethylene dicarbamate, which belongs to the field of organic chemical intermediates. Background technique [0002] 1,6-Hexamethylene dicarbamate (HDU) is a widely used organic chemical intermediate, especially as a raw material for the synthesis of isocyanate, melamine derivatives and polyvinylamine. Nowadays, butyl 1,6-hexamethylene dicarbamate (HDI) is an isocyanate in great demand, and there is a demand for a large amount of raw material production. The traditional method for preparing 1,6-hexamethylene dicarbamate has the following several methods: (1) Xuan Meifu etc. use metal halides supported by activated carbon to catalyze HAD and chloroformate to synthesize HDU; (2) ) FranzMerger et al reported the alcoholysis reaction of HAD and urea in excess alcohol to prepare HDU; (3) the preparation of HDU by ammonolysis of dimethyl carbonate, the process is mild and zero emission can be ac...

Claims

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Application Information

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IPC IPC(8): C07C271/12C07C269/04
Inventor 王晓伟
Owner 王晓伟