Refining method of butroxydim

Abstract

The invention discloses a butroxydim refining method which comprises the following steps: (1) dissolving a butroxydim crude product in dichloromethane, adding water, dropwise adding an inorganic alkali solution, and standing for layering; (2) dropwise adding hydrochloric acid into the water phase to separate out butroxydim, and centrifuging; (3) adding solids obtained by centrifugation into an organic solvent, then adding activated carbon, heating, refluxing, decolorizing, dehydrating and carrying out filter pressing; and (4) cooling and crystallizing the filtrate, carrying out filter pressing, and drying a filter cake to obtain a butroxydim refined product. According to the refining method disclosed by the invention, impurities in the butroxydim are effectively removed through an alkali dissolution and acid precipitation method, and then the decoloration and dehydration treatment is performed, so that the purity of the butroxydim can be improved to 98% or above from about 90%, and the refining method is simple and convenient to operate, relatively low in cost, relatively high in refined product purity and suitable for industrial mass production.

Description

Technical Field

[0001] The invention belongs to the technical field of compound refining, and particularly relates to a method for refining butyclothion. Background Art

[0002] Butroxydim is a cyclohexenone herbicide developed by Zeneca. It is a post-emergence herbicide for broad-leaved crops and is mainly used to control grass weeds. The structural formula of butroxydim is as follows: .

[0003] At present, butyclotrimazole is basically obtained by the Friedel-Crafts acylation reaction of trimethylolpropane and n-butyryl chloride. The reaction formula is as follows: .

[0004] At present, the content of industrial products of trimethylol is usually only about 95%, and the content of crude trimethylol obtained by Friedel-Crafts acylation reaction is usually only about 92%, and the water content is relatively high, which makes it difficult to meet the formulation requirements.

[0005] So far, no literature reports on the refining of butyclobutanil have been found. Summary of the invention

[0006] The object of the present invention is to solve the above problems and provide a method for refining butyroxene which is simple to operate, low in cost, high in purity of the refined product and suitable for large-scale industrial production.

[0007] The technical solution for achieving the purpose of the present invention is: a method for refining butyclobutanil, comprising the following steps: ① Dissolve the crude product of butyrochlore in dichloromethane, then add water first, then drop the inorganic alkali solution, and let it stand to separate the layers.

[0008] ② Add hydrochloric acid dropwise to the aqueous phase to precipitate butyroxene and centrifuge.

[0009] ③ Add the solid obtained by centrifugation to an organic solvent, then add activated carbon, heat and reflux to decolorize and dehydrate, and filter press.

[0010] ④ Cool the filtrate to crystallize, filter by pressure, and dry the filter cake to obtain the fine product of butyclobutanil.

[0011] In the above step ①, the weight ratio of the crude butyclobutrim to the dichloromethane is 1:3 to 1:10, preferably 1:5.

[0012] In the above step ①, the inorganic base is sodium hydroxide, potassium hydroxide or lithium hydroxide, preferably sodium hydroxide.

[0013] In the above step ①, the inorganic base solution is added dropwise until the system pH is 12-13.

[0014] In the above step ②, the hydrochloric acid is added dropwise until the system pH is 2-3.

[0015] In the above step ③, the organic solvent is petroleum ether, methylcyclohexane, cyclohexane, n-hexane or heptane, preferably petroleum ether.

[0016] The weight ratio of the organic solvent in step ③ to the crude butyclobutanil in step ① is 3:1 to 6:1, preferably 4:1.

[0017] The weight ratio of the activated carbon in step ③ to the crude butyclobutanil in step ① is 0.05:1 to 0.2:1, preferably 0.1:1.

[0018] The present invention has the positive effects that: the refining method of the present invention first effectively removes impurities in butyronitrile by an alkali dissolution and acid precipitation method, and then performs a decolorization and dehydration treatment, thereby being able to increase the purity of butyronitrile from about 90% to more than 98%, and the operation is simple, the cost is low, the purity of the refined product is high, and the method is suitable for large-scale industrial production. DETAILED DESCRIPTION

[0019] (Example 1) The method for refining butyclothion of this embodiment comprises the following steps: ① Turn on the circulating water, control the temperature at about 25°C, add 200kg of crude butyclobutanil (purity is 90%) and 1000kg of dichloromethane into the alkalization reactor, stir to dissolve, first add 800kg of water, then add 180kg of 10wt% sodium hydroxide aqueous solution dropwise, continue stirring for 1h after the dropwise addition, the system pH is 12-13, and stand to separate.

[0020] ② Transfer the water layer into the acidification reactor, start the circulating water and stirring, control the temperature at about 25°C, add 55kg, 30wt% hydrochloric acid to the acidification reactor to precipitate the solid, continue stirring for 1h after the addition, the system pH = 2~3, and centrifuge.

[0021] ③ Transfer the off-white solid obtained by centrifugation into a decolorization reactor, add 800 kg of petroleum ether (boiling range 90-120 ° C) and 20 kg of activated carbon, start stirring, steam heat reflux decolorization and dehydration for 2 hours, and filter press.

[0022] ④ The filtrate was transferred to a crystallization kettle, slowly cooled to 20°C and kept warm for 2h to precipitate crystals, then cooled to 0°C, filtered, and the filter cake was dried to obtain 168kg of butylpyraclostrobin refined product with a purity of 99.0% and a refining yield of 92.4%.

[0023] (Example 2 to Example 4) The purification methods of each embodiment are basically the same as those of Example 1, except for the type of organic solvent and the amount of activated carbon used in step ③, as shown in Table 1.

[0024] Table 1 Example 1 Example 2 Example 3 Example 4 The organic solvent in step ③ 800kg petroleum ether (boiling range 90~120℃) 800kg petroleum ether (boiling range 90~120℃) 800kg methylcyclohexane 800kg cyclohexane Activated carbon 20kg 30kg 20kg 20kg Butyclothiocarb Refined Products 168kg 160kg 163kg 161kg Purity of refined products 99.0% 99.3% 98.1% 98.0% Refining yield 92.4% 88.3% 88.8% 87.7%

Claims

1. A method for refining butyclotrimone, comprising the following steps: ① Dissolve the crude product of butyclobutanil in dichloromethane, then add water first, then drop the inorganic alkali solution, and let stand to separate the layers; ② Add hydrochloric acid dropwise to the aqueous phase to precipitate butyroxene and centrifuge; ③ Add the solid obtained by centrifugation to an organic solvent, then add activated carbon, heat and reflux for decolorization and dehydration, and filter press; ④ Cool the filtrate to crystallize, filter by pressure, and dry the filter cake to obtain the fine product of butyclobutanil.

2. The method for refining butyclobutanil according to claim 1, characterized in that: In the above step ①, the weight ratio of the crude butyclobutanil to the dichloromethane is 1:3 to 1:

10.

3. The method for refining butyclotrimone according to claim 1, characterized in that: In the above step ①, the inorganic base is sodium hydroxide, potassium hydroxide or lithium hydroxide.

4. The method for refining butyclotrimone according to claim 1, characterized in that: In the above step ①, the inorganic base solution is added dropwise until the system pH is 12-13.

5. The method for refining butyclotrimone according to claim 1, characterized in that: In the above step ②, the hydrochloric acid is added dropwise until the system pH is 2-3.

6. The method for refining butyclobutanil according to any one of claims 1 to 5, characterized in that: In the above step ③, the organic solvent is petroleum ether, methylcyclohexane, cyclohexane, n-hexane or heptane.

7. The method for refining butyclobutanil according to claim 6, characterized in that: The organic solvent is petroleum ether.

8. The method for refining butyclobutanil according to claim 6, characterized in that: The weight ratio of the organic solvent in the above step ③ to the crude butyclobutanil in the above step ① is 3:1 to 6:

1.

9. The method for refining butyclobutanil according to any one of claims 1 to 5, characterized in that: The weight ratio of the activated carbon in step ③ to the crude butyclobutanil in step ① is 0.05:1 to 0.2:1.