A kind of method of synthesizing blastamide

Abstract

The invention relates to a novel method for synthesizing fenoxanil serving as a systemic fungicide. The novel method for synthesizing fenoxanil serving as the systemic fungicide comprises the following steps: adding 2,4-dichlorophenol, sodium hydroxide and 2-methyl chloropropionate into a methyl benzene solvent, controlling reaction temperature at 30-70 DEG C, washing methyl benzene phase by using water after the reaction is ended, and carrying out reduced pressure distillation on a solvent of the washed methyl benzene phase to obtain dichlorprop methyl ester; and adding the obtained dichlorprop methyl ester into a methyl benzene solution with dissolved 2-amino-2,3-dimethyl butyronitrile and sodium bicarbonate, reacting by controlling the reaction temperature at 0-30 DEG C, washing the methyl benzene phase by using water after the reaction is ended, carrying out reduced pressure distillation on a solvent of the washed methyl benzene phase, recrystallizing by using a mixed solvent of water and ethyl alcohol, reducing the temperature to the room temperature, and filtering to obtain the fenoxanil. According to the synthesis method, 2-chloropropionic acid is replaced by 2-methyl chloropropionate; dipropionyl chloride is replaced by the generated dichlorprop methyl ester; one-step acylation reaction is eliminated; the process route is simplified; the reaction period is shortened; the method has great development in the industrial production.

Description

technical field

[0001] The invention belongs to the field of chemical industry, and in particular relates to a new method for synthesizing rice blast amide. Background technique

[0002] Rice blast amide, also known as cyanobactam, is a novel systemic fungicide for the control of rice blast, widely used in rice sheath blight, rice blast and rice bacterial blight. The existing synthetic method of the product adopts the reaction of 2-chloropropionic acid and 2,4-dichlorophenol to generate dropwise propionic acid chloride. There are also bibliographical reports, in the mixed system of the toluene liquid that is dissolved with 2-amino-2,3-dimethylbutyronitrile and the aqueous solution that is dissolved with sodium bicarbonate, add the toluene liquid of propionic acid chloride, keep the reaction in the ice-water bath. conditions to produce blastamide. The process is complicated, the reaction time is long, and acid gas sulfur dioxide and hydrogen chloride are also produced, whic...

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