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Method for preparing n-alkyl p-toluenesulfonamide

A technology of p-toluenesulfonamide and p-toluenesulfonic acid, which is applied in the preparation of sulfonamide and organic chemistry, and can solve the problems of large environmental pollution

Inactive Publication Date: 2017-04-12
JIAXING UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

P-toluenesulfonyl chloride has high activity, but it has great environmental pollution

Method used

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  • Method for preparing n-alkyl p-toluenesulfonamide

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Dissolve 3.444g (20mmol) of anhydrous p-toluenesulfonic acid and 0.172g of 2-bromophenylboronic acid in 20g of dichloromethane, add 5g of molecular sieve type 5A, stir in an ice-water bath until the temperature reaches 0°C for 2h, then add 2.193 g (30 mmol) n-butylamine. After keeping at 0°C for 24 hours, remove the molecular sieves by filtration, and wash the filtrate once with 10 mL of 0.5 mol / L hydrochloric acid solution, 10 mL of 0.5 mol / L sodium hydroxide solution and 10 mL of saturated NaCl solution. After the organic phase was dried with anhydrous sodium sulfate, the desiccant was removed, the solvent dichloromethane was recovered by distillation, and the crude product of N-butyl-p-toluenesulfonamide was obtained. After the crude product was washed with 50% ethanol aqueous solution, 1.871 g of the product was obtained by drying. According to liquid chromatography analysis, the active ingredient is 98.4%, the yield is 40.5%, and the melting range is 71.3-74.5°C. ...

Embodiment 2

[0021] Dissolve 3.444g (20mmol) of anhydrous p-toluenesulfonic acid, 0.172g DMAP and 6.2g DCC in dichloromethane, add 5g molecular sieve type 5A, stir in a water bath until the temperature reaches 10°C for 2h, then add 2.193g (30mmol ) n-butylamine. After keeping at 10°C for 24 hours, remove the molecular sieves by filtration, and wash the filtrate once with 10 mL of 0.5 mol / L hydrochloric acid solution, 10 mL of 0.5 mol / L sodium hydroxide solution and 10 mL of saturated NaCl solution. The organic phase was dried with anhydrous sodium sulfate to remove the desiccant, distilled to recover the solvent dichloromethane, and obtained the crude product of N-butyl-p-toluenesulfonamide, which was washed with 50% ethanol aqueous solution and dried to obtain 1.648 g of the product, which was obtained by According to liquid chromatography analysis, the active ingredient is 96.3%, the yield is 34.9%, and the melting range is 69.3-74.5°C.

Embodiment 3

[0023] 3.444g (20mmol) anhydrous p-toluenesulfonic acid and 0.344g phosphotungstic acid loaded heteropolyacid ionic liquid [Etmim]EtOSO 3 Dissolve in dichloromethane, add 5g molecular sieve type 5A, stir in a water bath until the temperature reaches 20°C for 2h, then add 2.193g (30mmol) n-butylamine. After keeping at 20°C for 24 hours, remove the molecular sieves by filtration, and wash the filtrate once with 10 mL of 0.5 mol / L hydrochloric acid solution, 10 mL of 0.5 mol / L sodium hydroxide solution and 10 mL of saturated NaCl solution. The organic phase was dried over anhydrous sodium sulfate to remove the desiccant, distilled to recover the solvent dichloromethane, and obtained the crude product of N-butyl-p-toluenesulfonamide. According to liquid chromatography analysis, the active ingredient is 95.7%, the yield is 10.9%, and the melting range is 70.6-73.3°C.

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Abstract

The invention discloses a method for preparing N-alkyl-p-toluenesulfonamide. The method comprises the following steps: (1) dissolving anhydrous p-toluenesulfonic acid in a dichloromethane solvent, adding a catalyst and a molecular sieve 5A, and controlling the temperature to be 0-40 DEG C; (2) adding primary amine for a reaction, wherein the reaction temperature is 0-40 DEG C; (3) after the reaction is finished, carrying out suction filtration to remove the molecular sieve 5A; (4) washing a filtrate with an acid solution, then carrying out washing with an alkali solution and a salt solution in sequence, carrying out separation to obtain an organic phase, removing a drying agent after drying the organic phase with anhydrous sodium sulfate, and carrying out distillation to recover dichloromethane and obtain a crude product of N-alkyl-p-toluenesulfonamide; (5) carrying out washing with a 50% ethanol water solution, and carrying out weighing after drying. The method has the advantages that the catalyst is used, so that anhydrous p-toluenesulfonic acid can be directly reacted with primary amine in the dichloromethane organic solvent at low temperature; the molecular sieve 5A is added in the reaction between anhydrous p-toluenesulfonic acid and primary amine as a water absorbent, so that water generated in the reaction can be absorbed to ensure a smooth reaction process. According to liquid chromatography analysis, the purity and the yield of N-alkyl-p-toluenesulfonamide exceeds 98% and reaches about 40% respectively.

Description

technical field [0001] The invention relates to a method for preparing N-alkyl p-toluenesulfonamide, a method for preparing N-alkyl p-toluenesulfonamide from p-toluenesulfonic acid and primary amine. Background technique [0002] N-Alkyl-p-toluenesulfonamides are widely used in plasticizers, polyamides, cellulose, hot-melt adhesives and plasticizing inks, and have considerable application value. At present, the main method for the synthesis of N-alkyl p-toluenesulfonamides is to react p-toluenesulfonyl chlorides with primary amines to obtain N-alkyl p-toluenesulfonamides. P-toluenesulfonyl chloride has high activity, but it is highly polluting to the environment. If N-alkyl p-toluenesulfonamide is directly prepared by anhydrous p-toluenesulfonic acid, the pollution caused by waste acid can be greatly reduced. Contents of the invention [0003] The object of the invention is to propose a method for preparing N-alkyl-p-toluenesulfonamides, directly preparing N-alkyl-p-tolu...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C311/16C07C311/20C07C303/38
Inventor 吴建一屠晓华缪程平徐聪沈静飞张洋李宁
Owner JIAXING UNIV