Preparation method of symmetric urea compound

A compound and urea technology, applied in the field of preparation of symmetrical urea compounds, can solve the problems of unfriendly environment, unfavorable large-scale application, etc., and achieve the effects of good yield, wide substrate applicability and simple operation process

Active Publication Date: 2020-05-08
ZHEJIANG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the above methods have some disadvantages, such as the need for transition metals, harsh conditions such as high temperature and high pressure, and highly toxic substances such as halogens or azide reagents, and additional amines need to be added. The system is not friendly to the environment and is not conducive to large-scale applications.

Method used

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  • Preparation method of symmetric urea compound
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  • Preparation method of symmetric urea compound

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Embodiment 1: the preparation of 1,3-bis (4-methoxyphenyl) urea

[0026] In a 500mL single-necked flask, add 4-methylphenylhydroxamic acid (formula Ⅰ-1, R 1 = 4-OCH 3 ) 23.40g (140mmol), 150mL water, 45.24g (2.5eq, 350mmol) DIPEA, in SO 2 f 2 In the atmosphere, stirring at 25°C for 2h, after the reaction, the reaction solution was filtered, and the filter cake was rinsed with acetonitrile to white to obtain 17.35g of 1,3-bis(4-methoxyphenyl)urea, the yield 91%.

[0027] Proton NMR spectrum: (500MHz, DMSO-d 6 ) (δ, ppm): 8.36 (s, 2H), 7.33 (d, J = 9.0Hz, 4H), 6.85 (d, J = 9.0Hz, 4H), 3.71 (s, 6H).

[0028] Carbon NMR spectrum: (126MHz, DMSO-d 6 )(δ, ppm): 154.31, 152.93, 132.92, 119.93, 113.94, 55.15.

[0029]

Embodiment 2

[0030] Embodiment 2: Preparation of 1,3-bis(4-methylphenyl)urea

[0031] In a 500mL single-necked flask, add 4-methylphenylhydroxamic acid (formula Ⅰ-2, R 1 =4-CH 3 ) 21.16g (140mmol), 150mL dichloromethane, 63.94g (3.0eq, 420mmol) DBU, in SO 2 f 2 In the atmosphere, stir at 25°C for 1 h, filter after the reaction, and rinse the filter cake with acetonitrile until white to obtain 15.64 g of 1,3-bis(4-methylphenyl)urea, with a yield of 93%.

[0032] Proton NMR spectrum: (500MHz, DMSO-d 6 ) (δ, ppm): 8.49 (s, 2H), 7.33 (d, J = 8.4Hz, 4H), 7.08 (d, J = 8.2Hz, 4H), 2.24 (s, 6H).

[0033] Carbon NMR spectrum: (126MHz, DMSO-d 6 )(δ, ppm): 152.62, 137.20, 130.51, 129.14, 118.24, 20.32.

[0034]

Embodiment 3

[0035] Embodiment 3: Preparation of 1,3-bis(3-chlorophenyl)urea

[0036] In a 500mL single-necked flask, add 3-chlorophenylhydroxamic acid (formula Ⅰ-3, R 1 =3-Cl) 24.02g (140mmol), 150mL acetonitrile, 18.10g (3.0eq, 420mmol) Na 2 CO 3 , at SO 2 f 2 Stir at 30° C. for 6 h in the atmosphere, filter after the reaction, and wash the filter cake with acetonitrile until white to obtain 18.11 g of 1,3-bis(3-chlorophenyl)urea with a yield of 92%.

[0037] Proton NMR spectrum: (500MHz, DMSO-d 6 ) (δ, ppm): 9.81 (s, 2H), 7.69 (s, 2H), 7.36–7.24 (m, 4H), 7.02 (dt, J = 6.7, 2.2 Hz, 2H).

[0038] Proton NMR spectrum: (126MHz, DMSO-d 6 )(δ, ppm): 152.46, 141.18, 133.18, 130.40, 121.44, 117.28, 116.36.

[0039]

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Abstract

The invention discloses a preparation method of a symmetric urea compound, which comprises the following steps: by using a hydroxamic acid compound as a raw material, sequentially adding an alkali anda solvent, reacting at 25-50 DEG C for 1-7 hours in an SO2F2 atmosphere, and carrying out aftertreatment on the reaction solution to obtain the symmetric urea compound. According to the invention, cheap, easily available and environment-friendly SO2F2 is used as an accelerant to efficiently promote the generation of an isocyanate intermediate to form a C-N bond. The generation of isocyanate avoids the use of a large amount of halogen or azide dangerous reagents, so that the compound can be used as a green substitute for standard treatment conditions in Curtius rearrangement and Hofmann rearrangement reactions. The amine source in the final product only comes from hydroxylamine, and no additional amine needs to be added, so that the substrate is wide in applicability, and the correspondingsymmetric urea compound can be obtained at a relatively good yield. The operation process is simple, the aftertreatment only needs filtering, and the method is suitable for large-scale preparation.

Description

[0001] (1) Technical field [0002] The preparation of a kind of symmetrical urea compound of the present invention particularly relates to utilizing sulfuryl fluoride (SO 2 f 2 ) as a new method to promote the Rosen rearrangement reaction of hydroxamic acid to produce symmetrical urea as an accelerator. [0003] (2) Background technology [0004] Symmetrical urea compounds, especially aromatic symmetrical urea compounds, are widely used in medicine, pesticides, materials, and catalysts due to their special chemical structures and physical properties. One of the most traditional methods for the preparation of symmetrical ureas is through the reaction of amines with phosgene or its derivatives. From the perspective of the reaction process, the use of highly toxic reagents limits the large-scale application of this method. In recent years, in the presence of transition metal catalysts, carbon monoxide or carbon dioxide can be used to directly carbonylate primary amines to synt...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C273/18C07C275/34C07C275/28C07C275/30
CPCC07C273/1809C07C275/34C07C275/28C07C275/30
Inventor 丁成荣崔银张国富赵以勇吕井辉
Owner ZHEJIANG UNIV OF TECH
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