Methods for preparing N-alkoxycarbonyl isothiocyanate and derivative thereof

A technology of alkoxycarbonyl isothiocyanate and its derivatives, which is applied in the field of preparation of isothiocyanate and its derivatives, can solve the problems of low reaction efficiency, difficulty in catalyst removal, high catalyst toxicity, etc., and achieve catalytic High efficiency, non-toxic catalyst, and less waste water generation

Active Publication Date: 2011-08-31
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The existing catalysts have problems such as high catalyst toxicity, low reaction

Method used

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  • Methods for preparing N-alkoxycarbonyl isothiocyanate and derivative thereof

Examples

Experimental program
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Example Embodiment

[0035] Example 1 Preparation of N-ethoxycarbonyl isothiocyanate

[0036] Dissolve 2.5 parts of N-(N',N'-dimethylaminopropyl)methyl isobutylimine with a purity of 99% in 200 parts of cyclohexane, and add 45.3 parts of thiocyanate with a purity of 98.5% Sodium, cool the mixture to a temperature of 0°C to 5°C with stirring. Under this temperature range and stirring, 54.3 parts of ethyl chloroformate with a purity of 98.5% were added to the reaction mixture, stirred and reacted for 3 hours, and the reaction was completed. Add 100 parts of water to dissolve the sodium chloride precipitate generated by the reaction, and separate the water phase to remove the water phase. The oil phase is distilled under reduced pressure to remove the solvent cyclohexane to obtain the desired N-ethoxycarbonyl isothiocyanate product. Analysis showed that the yield of the product based on ethyl chloroformate was 98.4%.

Example Embodiment

[0037] Example 2 Preparation of N-ethoxycarbonyl-0-ethylthiocarbonyl carbamate

[0038] The N-ethoxycarbonyl isothiocyanate product prepared according to Example 1 was added to 115 parts of ethanol while maintaining the temperature of the reaction mixture between about 25°C and about 45°C. The reaction mixture was then stirred at a temperature of about 40°C to 45°C for about 2 hours. The resulting product is an ethanol solution of N-ethoxycarbonyl-0-ethylthiocarbonyl carbamate. Analysis showed that the yield of the product based on ethyl chloroformate was 95.6%.

Example Embodiment

[0039] Example 3 Preparation of N-ethoxycarbonyl-0-isopropylthiocarbonyl carbamate (one-pot method)

[0040] Add 28 parts of N-(N',N'-dimethylaminopropyl) cyclohexanimine with a purity of 98% to 453 parts of NaSCN with a purity of 98% in 1000 parts of acetone, and then keep the temperature under stirring Between 10°C and about 25°C. 550 parts of 98.5% ethyl chloroformate were added to the reaction mixture in this temperature range and stirring. After the addition step, the reaction mixture is stirred and reacted at about 10°C to about 25°C for 4 hours to obtain N-ethoxycarbonyl isothiocyanate. Then, maintaining the reaction temperature between 10°C and 25°C, 491 parts of isopropanol was added with stirring. After the addition is complete, continue to stir and react for about 3 hours at a temperature of 45°C to 55°C, and the reaction is complete. The obtained mixture was washed with water, the aqueous phase was separated by liquid separation, and then the remaining acetone solv...

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Abstract

The invention discloses a method for preparing alkoxycarbonyl isothiocyanate, which comprises the following step of: reacting chloroformate with thiocyanate in an organic solvent by taking dialkyl amino alkyl imine Schiff base as a catalyst to generate N-alkoxycarbonyl isothiocyanate. The invention further provides a method for preparing an alkoxycarbonyl isothiocyanate derivative, which comprises the following steps of: reacting chloroformate with thiocyanate in the presence of an organic solvent and a catalytic amount of dialkyl amino alkyl imine Schiff base to generate an alkoxycarbonyl isothiocyanate intermediate product; and reacting the intermediate product with an alcohol, amine, thioalcohol or thiophenol compound to generate the alkoxycarbonyl isothiocyanate derivative. The methods disclosed by the invention have the advantages of catalyst nontoxicity, high catalysis efficiency, high product purity, small amount of waste water and the like.

Description

technical field [0001] The technical field to which the invention belongs is the preparation of isothiocyanate and derivatives thereof, and mainly relates to an improved method for preparing N-alkoxycarbonyl isothiocyanate and derivatives thereof. Background technique [0002] Isothiocyanate is an important fine chemical intermediate, which has a very wide range of applications in the fields of medicine, pesticides and mineral processing agents. Since R.E.Doran first synthesized N-ethoxycarbonyl isothiocyanate from ethyl chloroformate and lead thiocyanate in boiling toluene in 1896, it has been synthesized by the reaction of chloroformate and thiocyanate N-alkoxycarbonyl isothiocyanate has become the main method for preparing N-alkoxycarbonyl isothiocyanate and its derivatives. The catalyst is to improve the efficiency of the reaction process between chloroformate and thiocyanate The key to technology. [0003] U.S. Patent No. 4,659,853 discloses a reaction between halofor...

Claims

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Application Information

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IPC IPC(8): C07C331/32C07C327/22C07C335/28B01J31/02
Inventor 钟宏刘广义何谋海王帅夏柳荫曹占芳袁露
Owner CENT SOUTH UNIV
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