Preparation method of 2- chloro-6-trichloromethyl pyridine

Abstract

The invention provides a preparation method of 2-chloro-6-trichloromethyl pyridine. The method comprises the following steps: carrying out water gasification by taking 2-trichlormethyl as initial material, then taking activated carbon with metal ion oxides, such as Fe, Zn and the like as catalyst, taking nitrogen as carrier gas, reacting with chlorine and then generating 2-chloro-6-trichloromethylpyridine, and rectifying to obtain the finished product with the overall yield being more than 75 percent. In the preparation method, continuous reactions are adopted, and the operation is very safeand convenient; and meanwhile, hydrogen chloride generated by reaction is prepared into hydrochloric acid by water absorption as the used materials are less, excess chlorine and sodium hydroxide reactto prepare sodium hypochlorite, therefore, the emission amount of three wastes is less, which is environmental-friendly; and the production cost of the product is greatly reduced.

Description

technical field

[0001] The invention relates to a preparation method of 2-chloro-6-trichloromethylpyridine, in particular to a chemical preparation method of 2-chloro-6-trichloromethylpyridine. Background technique

[0002] Chloridine is a nitrification inhibitor, also known as a nitrogen fertilizer synergist, a class of organic compounds that are toxic to nitrifying bacteria. In 1962, Goring reported for the first time that chloropyridine had nitrification inhibitory properties. In 1974, DOW Chemical Company of the United States developed and produced a nitrification inhibitor product using the nitrification inhibitory properties of chloropyridine, and promoted its application in agriculture. They can selectively inhibit the activity of nitrifying bacteria in the soil, thereby slowing down the reaction speed of the transformation of ammonium nitrogen into nitrate nitrogen in the soil. Ammonium nitrogen can be absorbed by soil colloids and is not easy to lose. However, unde...

Examples

Embodiment 1

[0025] The method for synthesizing 2-chloro-6-trichloromethylpyridine in this example is mainly to use gaseous 2-picoline and water mixed gas as raw material, nitrogen as carrier gas, and chlorine gas to pass through a fixed bed loaded with catalyst Equipment for continuous reaction. The first step of the reaction operation is the activation of the catalyst. Mix ferric chloride and activated carbon according to the weight ratio of 1:99 and place them on a fixed bed. Turn on the heating system to raise the temperature of the catalyst and keep it warm to 290°C. After activating it with nitrogen at a rate of 0.6L per second for 30 minutes, stop the nitrogen to change the temperature. Feed in chlorine gas and activate at a rate of 0.9L per second for 1 hour. After the catalyst is activated, cool down the fixed bed equipment to 250°C to prepare for chlorination reaction. 200 g of 2-picoline (2.13 mol, content 99%) and 383 g of deionized water (21.3 mol) were added into a mixer for...

Embodiment 2

[0028] The method for synthesizing 2-chloro-6-trichloromethylpyridine in this example is basically the same as the method and reaction steps in Example 1, using a fixed-bed continuous reaction. The catalyst was changed to zinc chloride and activated carbon were mixed according to the weight ratio of 3:17, the introduction amount of 2-picoline and water in the reaction ratio was changed to 15:1mol, and the fixed bed reaction temperature was also adjusted to 280°C. 200 g of 2-picoline (2.13 mol, content 99%) and 575 g of deionized water (31.95 mol) were added to the mixture and mixed for reaction. Turn on the fixed bed tail gas absorption system, keep nitrogen at a rate of 0.5L per second, and chlorine gas at a rate of 0.8L per second through the preheater when the temperature reaches above 150°C, then connect to the fixed bed reaction equipment. The mixed 2-picoline aqueous solution is heated by the vaporizer and enters the fixed-bed reaction equipment in a completely vaporized...

Embodiment 3

[0030] The method for synthesizing 2-chloro-6-trichloromethylpyridine in this example is basically the same as the method and reaction steps in Example 1, using a fixed-bed continuous reaction. The catalyst is changed to cupric chloride and activated carbon is mixed according to the weight ratio of 3:7, the introduction amount of 2-picoline and water in the reaction ratio is changed to 15:1mol, and the fixed bed reaction temperature is also adjusted to 300°C. 200 g of 2-picoline (2.13 mol, content 99%) and 575 g of deionized water (31.95 mol) were added to the mixture and mixed for reaction. Turn on the fixed bed tail gas absorption system, keep nitrogen at a rate of 0.55L per second and chlorine at a rate of 1.0L per second through the preheater when the temperature reaches 150°C or more, then connect to the fixed bed reaction equipment. The mixed 2-picoline aqueous solution is heated by the vaporizer and enters the fixed-bed reaction equipment in a completely vaporized manne...

technical field

[0001] The invention relates to a preparation method of 2-chloro-6-trichloromethylpyridine, in particular to a chemical preparation method of 2-chloro-6-trichloromethylpyridine. Background technique

[0002] Chloridine is a nitrification inhibitor, also known as a nitrogen fertilizer synergist, a class of organic compounds that are toxic to nitrifying bacteria. In 1962, Goring reported for the first time that chloropyridine had nitrification inhibitory properties. In 1974, DOW Chemical Company of the United States developed and produced a nitrification inhibitor product using the nitrification inhibitory properties of chloropyridine, and promoted its application in agriculture. They can selectively inhibit the activity of nitrifying bacteria in the soil, thereby slowing down the reaction speed of the transformation of ammonium nitrogen into nitrate nitrogen in the soil. Ammonium nitrogen can be absorbed by soil colloids and is not easy to lose. However, unde...

Examples

Embodiment 1

[0025] The method for synthesizing 2-chloro-6-trichloromethylpyridine in this example is mainly to use gaseous 2-picoline and water mixed gas as raw material, nitrogen as carrier gas, and chlorine gas to pass through a fixed bed loaded with catalyst Equipment for continuous reaction. The first step of the reaction operation is the activation of the catalyst. Mix ferric chloride and activated carbon according to the weight ratio of 1:99 and place them on a fixed bed. Turn on the heating system to raise the temperature of the catalyst and keep it warm to 290°C. After activating it with nitrogen at a rate of 0.6L per second for 30 minutes, stop the nitrogen to change the temperature. Feed in chlorine gas and activate at a rate of 0.9L per second for 1 hour. After the catalyst is activated, cool down the fixed bed equipment to 250°C to prepare for chlorination reaction. 200 g of 2-picoline (2.13 mol, content 99%) and 383 g of deionized water (21.3 mol) were added into a mixer for...

Embodiment 2

[0028] The method for synthesizing 2-chloro-6-trichloromethylpyridine in this example is basically the same as the method and reaction steps in Example 1, using a fixed-bed continuous reaction. The catalyst was changed to zinc chloride and activated carbon were mixed according to the weight ratio of 3:17, the introduction amount of 2-picoline and water in the reaction ratio was changed to 15:1mol, and the fixed bed reaction temperature was also adjusted to 280°C. 200 g of 2-picoline (2.13 mol, content 99%) and 575 g of deionized water (31.95 mol) were added to the mixture and mixed for reaction. Turn on the fixed bed tail gas absorption system, keep nitrogen at a rate of 0.5L per second, and chlorine gas at a rate of 0.8L per second through the preheater when the temperature reaches above 150°C, then connect to the fixed bed reaction equipment. The mixed 2-picoline aqueous solution is heated by the vaporizer and enters the fixed-bed reaction equipment in a completely vaporized...

Embodiment 3

[0030] The method for synthesizing 2-chloro-6-trichloromethylpyridine in this example is basically the same as the method and reaction steps in Example 1, using a fixed-bed continuous reaction. The catalyst is changed to cupric chloride and activated carbon is mixed according to the weight ratio of 3:7, the introduction amount of 2-picoline and water in the reaction ratio is changed to 15:1mol, and the fixed bed reaction temperature is also adjusted to 300°C. 200 g of 2-picoline (2.13 mol, content 99%) and 575 g of deionized water (31.95 mol) were added to the mixture and mixed for reaction. Turn on the fixed bed tail gas absorption system, keep nitrogen at a rate of 0.55L per second and chlorine at a rate of 1.0L per second through the preheater when the temperature reaches 150°C or more, then connect to the fixed bed reaction equipment. The mixed 2-picoline aqueous solution is heated by the vaporizer and enters the fixed-bed reaction equipment in a completely vaporized manne...

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