Method for preparing cyanopyridine by using chloropyridine under the catalysis of ligand-free palladium

A technology of chloropyridine and cyanopyridine, which is applied in the field of preparing cyanopyridine from chloropyridine under the catalysis of ligand-free palladium, can solve the problems of limited picoline sources, high temperature and high pressure, etc., and achieve the reduction of waste acid hazards, The effect of reducing the post-processing process and reducing costs

Active Publication Date: 2010-02-17
NANJING REDSUN BIOCHEM CO LTD +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] For the cyanation research of chloropyridine, the methyl pyridine is generally converted into a cyano group through the ammoxidation method of pi

Method used

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  • Method for preparing cyanopyridine by using chloropyridine under the catalysis of ligand-free palladium

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Experimental program
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Embodiment 1

[0023] Potassium ferrocyanide trihydrate (557mg, 1.32mmol), 3-chloropyridine (678mg, 6mmol), potassium carbonate (828mg, 6mmol), palladium acetate (20mg, 0.03mmol) were dissolved in 100mL N, N-dimethylethyl Amide, nitrogen protection. Heat to 120°C for 3 hours. After the reaction, the temperature returned to room temperature, and the reaction solution was diluted with 100 mL of ethyl acetate. Filter, and wash the filtrate twice with 80 mL of water and 5% ammonia water respectively. The organic phase was dried over anhydrous magnesium sulfate. The volatile substances were removed by rotary evaporation to obtain 524 mg of the product 3-cyanopyridine with a yield of 84%. The conversion of 3-chloropyridine was 90%.

Embodiment 2

[0025] Potassium ferrocyanide (736mg, 2mmol), 2-chloro-3-picoline (1276mg, 10mmol), potassium carbonate (276mg, 2mmol), palladium acetate (33.5mg, 0.05mmol) were dissolved in 200mL 1,4- Dioxane, argon protection. Heat to 100°C for 1 hour. After the reaction, the temperature returned to room temperature, and the reaction solution was diluted with 200 mL of chloroform. Filter, and wash the filtrate twice with 150 mL of water and 5% ammonia water respectively. The organic phase was dried over sodium sulfate. The volatile substances were removed by rotary evaporation to obtain 932 mg of the product 2-cyano-3-methylpyridine with a yield of 79%. The conversion of 2-chloro-3-picoline was 95%.

Embodiment 3

[0027] Potassium ferrocyanide (3680mg, 10mmol), 2-chloro-3,5-lutidine (1416mg, 10mmol), potassium carbonate (1380mg, 10mmol), palladium acetate (67.4mg, 0.1mmol) were dissolved in 300mL di Methyl sulfoxide, nitrogen protection. Heat to 135°C for 4 hours. After the reaction, the temperature returned to room temperature, and the reaction solution was diluted with 300 mL of ethyl acetate. Filter, and wash the filtrate twice with 200 mL of water and 5% ammonia water respectively. The organic phase was dried over anhydrous magnesium sulfate. The volatile substances were removed by rotary evaporation to obtain 990 mg of the product 2-cyano-3,5-lutidine with a yield of 75%, and the conversion rate of 2-chloro-3,5-lutidine was 82%.

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Abstract

The invention discloses a method for preparing cyanopyridine by using chloropyridine under the catalysis of ligand-free palladium, and the method comprises the following steps: in the organic solvent,adopting chloropyridine and potassium ferrocyanide as raw material and potassium carbonate-palladium acetate as catalyst to react at 40-200 DEG C for 2-20h under the protection of inert gas and obtaining cyanopyridine. The method that cyanopyridine is prepared through the catalysis of ligand-free palladium adopts accessible potassium ferrocyanide as source of cyano group so as to avoid the use ofvirulent cyanides such as sodium cyanide, potassium cyanide and the like, reduce the damage of waste acid and the operational hazard, lower the post-treatment load and not need to add expensive phosphine ligand. The operation is simple, thus being applicable to the large-scale production of cyanopyridine compounds.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a method for preparing cyanopyridine from chloropyridine under the catalysis of ligand-free palladium. Background technique [0002] Aromatic nitrile is an important intermediate used in pharmaceuticals, agriculture (herbicides, insecticides), leather, dyes. For example, the Merck Index 13th Edition lists 22 compounds containing this functional group. The traditional method for preparing aromatic nitriles is the Rosenmond-Von Lauburn reaction, that is, the reaction between bromoarenes or iodoarenes and cuprous cyanide, which generally requires a higher temperature and the post-treatment is also very complicated. Such as Chem.Rev.1948, 42, 189 and J.Org.Chem.1961, 26, 2522. In 1973, Takagi invented the metal-catalyzed cyanation reaction of arenes for the first time. (Chem Letters 1973, 5, 471) The method is based on potassium cyanide and 2mol% Pd (CN) 2 It reacts wi...

Claims

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Application Information

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IPC IPC(8): C07D213/84C07D213/85B01J31/26B01J31/04
Inventor 芮忠南李维思王红明葛九敢周典海
Owner NANJING REDSUN BIOCHEM CO LTD
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