A kind of preparation method of imidacloprid
A technology of imidacloprid and chloromethylpyridinone, which is applied in the fields of resisting vector-borne diseases and organic chemistry, can solve the problems of carcinogenicity and affecting the quality of imidacloprid products, and achieve the effect of improving quality and reducing content
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[0026] The invention provides a preparation method of imidacloprid, comprising the following steps:
[0027] Mixing 2-chloro-5-chloromethylpyridine butanone solution, butanone, phase transfer catalyst, imidazolidine and sodium hydroxide to obtain a mixed solution;
[0028] The mixed solution is subjected to a substitution reaction to obtain an initial reaction solution of imidacloprid;
[0029] The initial reaction solution of imidacloprid is sequentially desolvated and washed, and the organic phase is taken to obtain a purified reaction solution of imidacloprid; the washing includes water and butanone;
[0030] The imidacloprid purification reaction solution and the oxidant are subjected to oxidation reaction to obtain the imidacloprid oxidation reaction solution;
[0031] The imidacloprid oxidation reaction solution is crystallized to obtain the imidacloprid;
[0032] The oxidant includes FeCl 3 , MnO 2 and KMnO 4 one or more of.
[0033] In the present invention, unle...
Embodiment 1
[0061] Mix 100g butanone and 32.4g 2-chloro-5-chloromethylpyridine in a dropping funnel to prepare 132.4g 2-chloro-5-chloromethylpyridine butanone solution, in which 2-chloro-5-chloromethylpyridine The mass concentration of pyridine is 24.4%;
[0062] In the reaction flask, premix 200g butanone, 0.5g tetra-tert-butylammonium bromide, 31g imidazolidine and 3g sodium hydroxide with stirring at 65°C, and the stirring speed is 300r / min to obtain a premix;
[0063] 132.4g of 2-chloro-5-chloromethylpyridine butanone solution was added dropwise to the premixed solution at a rate of 25g / h. During the dropwise addition, the pH value of the system was measured every 30min. Sodium, keep the pH value of the system at 8, and after the dropwise addition is completed, a mixed solution is obtained;
[0064] The mixed solution was subjected to a substitution reaction at 65° C. and a stirring rate of 300 r / min for 4 h to obtain an initial reaction solution of imidacloprid;
[0065] The initia...
Embodiment 2
[0071] Mix 100g butanone and 32.4g 2-chloro-5-chloromethylpyridine in a dropping funnel to prepare 132.4g 2-chloro-5-chloromethylpyridine butanone solution, in which 2-chloro-5-chloromethylpyridine The mass concentration of pyridine is 24.4%;
[0072] In the reaction flask, 210g of butanone, 0.54g of tetra-tert-butylammonium bromide, 30.5g of imidazolidine and 3g of sodium hydroxide were stirred at 65°C for premixing, and the stirring speed was 300r / min to obtain a premixed solution;
[0073] 132.4g of 2-chloro-5-chloromethylpyridine butanone solution was added dropwise to the premixed solution at a rate of 25g / h. During the dropwise addition, the pH value of the system was measured every 30min. Sodium, keep the pH value of the system at 8, and after the dropwise addition is completed, a mixed solution is obtained;
[0074] The mixed solution was subjected to a substitution reaction at 65° C. and a stirring rate of 300 r / min for 4 h to obtain an initial reaction solution of i...
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