Preparation method of cyanopinnazone_Kain Industrial Additive

Background and overview^[1]

Cyanopinalone appears as white crystalline powder with a melting point of 66-72°C. Cyanopinalone is a ketone compound and an important intermediate for medicines and pesticides. It is mainly used in medicine to synthesize 1,1-dimethyl-3-uracil and is also a raw material for film photosensitive agents. At present, there are few published domestic research reports on the synthesis method of the pharmaceutical intermediate cyanopinalone. Therefore, studying the preparation method of cyanopinalone has important industrial application value.

Preparation method^[1]

There is research to provide a method for preparing the pharmaceutical intermediate 1-cyano-3,3-dimethyl-2-butanone with high product yield. This is achieved through the following technical solutions: a preparation method of pharmaceutical intermediate 1-cyano-3,3-dimethyl-2-butanone, using 1-chloro-3,3-dimethyl-2-butanone , sodium cyanide is used as raw material, in the presence of solvent, catalyst and water, the reaction time is 1-6.5h at a temperature of 70~95°C to prepare the pharmaceutical intermediate 1-cyano-3,3-dimethyl -2-Butanone. Further improvement is: the dosage ratio of 1-chloro-3,3-dimethyl-2-butanone, sodium cyanide, catalyst, solvent and water is calculated by mass: 1-chloro-3,3-dimethyl- 2-Butanone:sodium cyanide:catalyst:solvent:water=1:0.25~0.95:0.01~0.09:0.32~1.15:1.65~2.72.

The specific preparation of cyanopinacone is as follows: In a 250mL four-necked flask equipped with a thermometer, add 10g of solvent, 13.5g of 1-chloro-3,3-dimethyl-2-butanone, and sodium cyanide 8g, catalyst 0.3g, water 28g, install the condenser tube, start the stirrer, raise the temperature to 70-95°C, the reaction time is 1-6.5h (monitor the reaction with gas chromatography). After the reaction is completed, 80-95% of the solvent is recovered, and the remaining liquid is cooled, crystallized, and filtered to obtain cyanopinalone. The product yield is 85.71%.

Main reference materials

[1] CN201310671120.X Preparation method of pharmaceutical intermediate 1-cyano-3,3-dimethyl-2-butanone