Technology Research About The Synthesis Of The Intermediate Of Prothioconazole And Flonicamide

Prothioconazole is a three azole fungicide which has a broad spectrum of efficacy developed by Bayer, mainly used to prevent and control the plant diseases and insect pests of grains, wheat and barley, and beans. Flonicamide is a new pesticide developed by ISK, mainly used to prevent and control the plant diseases and insect pests of fruit, vegetables and cotton. Based on the literature researched,the preparation of 1-chloro-1-chloro-acetyl-cyclopropane and 4-(trifluoromethyl) nicotinic acid were introduced in detail through two parts in this article.(1)The synthesis of 1-chloro-1-chloro-acetyl-cyclopropane. Acetylbutyrolactone as the starting material, reacts with sulfuryl chloride to prepare 1-chloroacetylbutyrolactone. And then 3,5-dichloro-pentan-2-one was prepared by the opening reaction between the product of the previous step and concentrated hydrochloric acid in the solution of acetic acid. Then 1-acetyl-1-chloride cyclopropane was prepared by the n-cyclohexylmaleimide reaction, the sodium hydroxide aqueous solution reacts with 3,5-dichloro-pentan-2-one, under the catalysis of tetrabutyl ammonium bromide. Finally, cyclopropane carbonyl chloride was synthesized by the reaction of the product of the upon step with sulfuryl chloride. The total yield is 41.7%. It has a significantly improve contrast to the reference documents.(2)The synthesis of 4-(trifluoromethyl) nicotinic acid. First, cyanoacetamide reacts with ethyl 4,4,4-trifluoroacetoacetate and potassium hydroxide to prepare 3-cyano-2,6-dihydroxy-4-(trifluoromethyl)pyridine, and then the product reacts with POCl3 to prepare 3-cyano-2,6-dichloro-4-(trifluoromethyl) pyridine. Then 3-cyano-2,6-dichloro-4-(trifluoromethyl) nicotinamide was prepared by the hydrolysis reaction under acid condition. Then the product of the upon step to prepare the 3-cyano-4-(trifluoromethyl) pyridine by catalytic hydrogenation. And then the final product was prepared by hydrolysis under alkali condition, and then neutralize. The total yield is 42.5 %. The reference documents is just refer to 38.6%.The feasibilities of the synthesis processes of 1-chloro-1-chloro- acetyl- cyclopropane and 4-(trifluoromethyl) nicotinic acid have been studied respectively. Selecting that the economical process route. The specific factors of influence on the product yield were analyzed. Groups of relative ideal technological parameters were obtained. The synthetic routes supply a good foundation for industrial production.