- Dicamba preparation process
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The invention belongs to the technical field of herbicide dicamba preparation and relates to a dicamba preparation process. The dicamba preparation process includes steps: taking benzene as a raw material to generate 1,2,4-trichlorobenzene through directional chlorination, catalysis, re-chlorination and rectification; hydrolyzing the 1,2,4-trichlorobenzene to generate a mixture of 2,5-dichlorophenol and 2,4-dichlorophenol, and separating and purifying to obtain 2,5-dichlorophenol; using the 2,5-dichlorophenol to prepare 3,6-dichlorosalicylic acid; subjecting the 3,6-dichlorosalicylic acid to methylation, saponification, acidification and the like to obtain dicamba. By optimization of technical steps and parameters, the whole dicamba preparation process has advantages of simplicity, low cost, high yield, high selectivity, remarkable reduction of wastewater and increase of equipment utilization rate.
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Paragraph 0051; 0052; 0053
(2017/04/03)
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- Preparation process of herbicide dicamba
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The invention relates to a preparation process of a herbicide dicamba, which belongs to the technical field of a herbicide dicamba preparation process. The preparation process comprises the following steps: separating a mixture of 3,6-dichlorosalicylic acid potassium salt and potassium carbonate by virtue of dissolution and crystallization ways to obtain qualified 3,6-dichlorosalicylic acid potassium salt and potassium carbonate, enabling the 3,6-dichlorosalicylic acid potassium salt to directly enter an etherification process, and directly returning the catalyst potassium carbonate to carbonization, so that the consumption of the potassium carbonate can be effectively reduced; the acidification step of hydrochloric acid is reduced, the consumption of a raw material hydrochloric acid can be reduced, and the effective utilization rate of the potassium carbonate can be increased. The process is high in total yield, short in production period, capable of greatly decreasing the production cost with only one alkaline liquid, and capable of increasing the additional value of byproducts.
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Paragraph 0072
(2017/05/05)
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