Preparation method and application of novel benzothiazole salt ionic liquid

A technology of benzothiazole salts and ionic liquids, which is applied in the preparation and application fields of new ionic liquids of benzothiazole salts, can solve the problems of small amount of benzothiazole salts, low yield of target products, and normal reaction, etc. Achieve the effects of reducing the use of organic solvents, good economy and environmental protection, and avoiding the use of substrates

Inactive Publication Date: 2011-08-17
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method requires the use of expensive and toxic iodoalkane reagents and the expensive LiTf 2 N or CF 3 SO 3 Na to ensure that the reaction substrate has enough activity to convert to the target product, however, the yield of the obtained target product is still low
Moreover, common anions with ionic liquids PF 6 - or BF 4 - The benzothiazole salt of the structure was also not prepared by this method, which is due to the PF 6 - or BF 4 - Reactivity is higher than that of Tf 2 N - or CF 3 SO 3 - low to allow the reaction to proceed normally
Few kinds of anio

Method used

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  • Preparation method and application of novel benzothiazole salt ionic liquid
  • Preparation method and application of novel benzothiazole salt ionic liquid
  • Preparation method and application of novel benzothiazole salt ionic liquid

Examples

Experimental program
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Effect test

Embodiment 1

[0025] Embodiment 1: (preparation of ionic liquid)

[0026] Preparation method one of N-n-butyl-benzothiazole tetrafluoroborate ionic liquid

[0027] In a 50 mL single-necked round bottom flask, add 0.05 mol of benzothiazole, 0.05 mol of n-butane bromide, and 0.05 mol of sodium tetrafluoroborate in sequence, and stir and react at 90° C. for 6 h. After the reaction is complete, a yellow paste is obtained. Cool to room temperature, add an appropriate amount of dichloromethane until the solid product is no longer dissolved, filter, and wash the filtrate with distilled water until the washing liquid is tested with silver nitrate and no precipitate is formed. Dichloromethane was recovered under reduced pressure, and the resulting solid was recrystallized in absolute ethanol to obtain a colorless needle-like solid product, which was N-n-butyl-benzothiazole tetrafluoroborate ionic liquid, dried in vacuum, and the calculated yield was 76%, melting point is 92-93°C.

Embodiment 2

[0028] Embodiment 2: (preparation of ionic liquid)

[0029] Preparation method two of N-n-butyl-benzothiazole tetrafluoroborate ionic liquid

[0030] Into a 50 mL single-necked round bottom flask, add 0.05 mol benzothiazole, 0.05 mol n-chlorobutane, 0.05 mol ammonium tetrafluoroborate in sequence, and stir the reaction at 100° C. for 10 h. After completion of the reaction, a light yellow paste was obtained, cooled to room temperature, added an appropriate amount of dichloromethane until the solid product was no longer dissolved, filtered, and the filtrate was washed with distilled water until the washing liquid was tested with silver nitrate and no precipitate was formed. Dichloromethane was recovered under reduced pressure, and the resulting solid was recrystallized in absolute ethanol to obtain a colorless needle-like solid product, which was N-n-butyl-benzothiazole tetrafluoroborate ionic liquid, dried in vacuum, and the calculated yield was 68%, the melting point is 92-93...

Embodiment 3

[0031] Embodiment 3: (preparation of ionic liquid)

[0032] Preparation method three of N-n-butyl-benzothiazole tetrafluoroborate ionic liquid

[0033] Into a 50 mL single-necked round bottom flask, add 0.05 mol of benzothiazole, 0.05 mol of n-butane bromide, and 0.05 mol of potassium tetrafluoroborate in sequence, and stir and react at 90° C. for 7 h. After completion of the reaction, a light yellow paste was obtained, cooled to room temperature, added an appropriate amount of dichloromethane until the solid product was no longer dissolved, filtered, and the filtrate was washed with distilled water until the washing liquid was tested with silver nitrate and no precipitate was formed. Dichloromethane was recovered under reduced pressure, and the resulting solid was recrystallized in absolute ethanol to obtain a colorless needle-like solid product, which was N-n-butyl-benzothiazole tetrafluoroborate ionic liquid, dried in vacuum, and the calculated yield was 81%, melting point...

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Abstract

The invention discloses a simple preparation method of benzothiazole salt ionic liquid and application thereof to organic catalytic synthesis. In the invention, the benzothiazole salt ionic liquid has a novel structure, benzothiazole N-alkyl quaternary ammonium salt is used as cations (alkyl is one of n-C4H9, n-C5H11 and n- C6H13), BF4<-> or PF6<-> is used as anions. In the preparation method, benzothiazole, chloralkane, alkyl bromide and alkali metal salt or ammonium salt which contains the target anions react in one step under a solvent-free condition. In the invention, the one-step method is used for preparing the benzothiazole salt ionic liquid, therefore, the preparation yield is greatly increased, the use of substrates with high toxicity and high price is avoided, the consumption of organic solvents is reduced, the excessive use of a certain reaction component is avoided, the preparation process is simplified and high product yield is ensured. Therefore, the method has god economy and environmental friendliness and is suitable for mass preparation. The benzothiazole salt ionic liquid can be used as a mild, exclusive and efficient catalyst in benzoin condensation and Biginelli condensation and can be recycled and reused many times.

Description

technical field [0001] The invention relates to a preparation method of a benzothiazolium salt ionic liquid and its application in organic synthesis, and belongs to the technical field of organic synthesis chemistry and catalytic reaction methods. Background technique [0002] Ionic Liquids (Ionic Liquids) are a class of low-temperature molten salts (melting point is usually lower than 100°C) composed of organic cations and organic or inorganic anions. They have the characteristics of non-volatility, high thermal stability, selective solubility and designability. . In recent years, ionic liquids have attracted much attention because of their good physical and chemical properties, and the research on ionic liquids has also extended to many fields such as chemistry, chemical engineering, and materials. However, most of the reports on ionic liquids focus on imidazole-based ionic liquids and less on other types of ionic liquids, which limits the development of ionic liquids to ...

Claims

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Application Information

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IPC IPC(8): C07D277/62B01J31/02C07C49/83C07C49/84C07C45/73C07D239/10
Inventor 姚舜宋航周贤思罗文锋张义文
Owner SICHUAN UNIV
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