Synthetic method of 1, 3-two substituted ureas and carbamate

A technology of carbamate and disubstituted urea, applied in 1 field, can solve problems such as difficult preparation of asymmetric urea, complex experimental operation, strong toxicity of raw materials, etc., and achieve cheap raw materials, simple experimental operation, and easy-to-use products Effect

Inactive Publication Date: 2012-06-20
WUHAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These methods have complicated experimental operations, strong toxicity of raw materials, high cost, and it is not easy to prepare asymmetric urea

Method used

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  • Synthetic method of 1, 3-two substituted ureas and carbamate
  • Synthetic method of 1, 3-two substituted ureas and carbamate
  • Synthetic method of 1, 3-two substituted ureas and carbamate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Embodiment 1, preparation of symmetrical 1,3-disubstituted urea

[0020] Screen the reaction conditions for the preparation of symmetrical 1,3-disubstituted urea 2a, including the reaction solvent, the amount of hypervalent iodine, the reaction temperature, and the reaction time. It was found that using dichloromethane as a solvent, adding iodobenzene oxide in a molar ratio of 1.5 times, and reacting at room temperature for 2 hours, the best yield of urea was 92%. The following preparations of urea are based on this standard condition.

[0021] Table 1: Screening of reaction conditions.

[0022]

[0023]

[0024] a Isolated yield

[0025] Dissolve the amide in dichloromethane, add iodobenzene oxide at a molar ratio of 1.5 times, and stir the reaction solution at room temperature for 2 hours. The reaction solution was filtered, concentrated, and petroleum ether and ethyl acetate were used as eluents, and the symmetrical 1,3-disubstituted urea was obtained by co...

Embodiment 2

[0032] Embodiment 2, preparation of asymmetric 1,3-disubstituted urea

[0033] The amide was dissolved in dichloromethane, 1.5 times molar ratio of amine and iodobenzene oxide were sequentially added, and the reaction solution was stirred at room temperature for 2 hours. The reaction solution was filtered and concentrated. The unsymmetrical 1,3-disubstituted urea was obtained by column chromatography with petroleum ether and ethyl acetate as eluent. The asymmetric 1,3-disubstituted urea prepared by this method and its yield are shown in Table 2, and all products have been proved by H NMR spectrum. Amides in this method include: aryl amides and aliphatic amides. No matter it is linear amine or cyclic amine, 1,3-disubstituted urea can be prepared in high yield. When diisopropylamine with large steric hindrance is used as the nucleophile, the yield of the prepared 1,3-disubstituted urea is as high as 93%.

[0034] Table 2: Preparation of unsymmetrical 1,3-disubstituted urea ...

Embodiment 3

[0057] Embodiment three, prepare carbamate

[0058] The amide was dissolved in alcohol, and 1.5 times molar ratio of iodobenzene oxide was added, and the reaction solution was stirred at room temperature for 2 hours. The reaction solution was filtered and concentrated. Carbamate was obtained by column chromatography using petroleum ether and ethyl acetate as eluent. The carbamates prepared by this method and their yields are shown in Table 3, and all products have been proved by proton nuclear magnetic resonance. Amines useful in this method include aryl amines as well as aliphatic amines. The alcohol used in this method has methanol. When isopropanol or tert-butanol with relatively large steric hindrance is used as nucleophile, no carbamate is formed and only symmetrical urea is obtained. The alkynyl group has no effect on the reaction when propargyl alcohol is used as the nucleophile.

[0059] Table 3: Preparation of carbamates

[0060]

[0061]

[0062] Reaction...

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Abstract

The invention relates to a simple and efficient preparation method of 1, 3-two substituted ureas and carbamate. The method comprises the steps as follows: amide is taken as substrate, and the 1, 3-two substituted ureas and carbamate are prepared by using Hofmann rearrangement reaction induced by hypervalent iodine. Only acid amide and oxidization iodobenzene are added into the reaction system, stirring is performed for 2 hours in methylene dichloride at a room temperature, and symmetrical 1, 3-two substituted ureas can be obtained with high yield. When acid amide, oxidization iodobenzene and nucleophilic agent amine are in reaction, and stirring is performed for 2 hours in methylene dichloride at a room temperature, unsymmetrical 1, 3- two substituted ureas can be obtained. When acid amide, oxidization iodobenzene and nucleophilic agent alcohol are in reaction, and stirring is performed for 2 hours in alcoholic solution at a room temperature, carbamate can be prepared. The method is simple to operate, the product selectivity is strong, and the application is wide.

Description

technical field [0001] The invention relates to a synthesis method of 1,3-disubstituted urea and carbamate, belonging to the field of organic chemistry. Background technique [0002] Ureas and urethanes are an important class of compounds in organic and medicinal chemistry. In addition, urea can be connected with other functional groups through hydrogen bonds, which has important applications in the fields of chiral catalysis and molecular recognition. Urea is usually synthesized by reacting amine with phosgene or isocyanate, and carbamate is synthesized by reacting amine with dimethyl carbonate. These methods are complex in experimental operation, highly toxic in raw materials, high in cost, and not easy to prepare asymmetric urea. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a method for synthesizing 1,3-disubstituted urea and carbamate. [0004] The method is a Hoffman rearrangement reaction induced by i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C273/18C07C275/16C07C275/06C07C275/26C07C275/24C07C275/28C07D295/215C07B43/00C07C269/00C07C271/28C07C271/12C07C271/24C07D235/26C07D263/58C07D498/04C07D263/22
Inventor 胡先明汪志明刘鹏
Owner WUHAN UNIV
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