Chlorantraniliprole Amide Synthesis Research

Chlorantraniliprole, invented by the DuPont, is a new class of anthranilic diamide insecticides, with the characters of high-efficacy, low-toxicity, broad-spectrum pest control and no harm to the environment. It is a highly potent and selective activator of insect ryanodine receptors with exceptional activity on a broad range of Lepidoptera. Chlorantraniliprole exhibits its action in insect calcium channels, by binding to ryanodine receptors and activating the uncontrolled release of calcium stores. Whole organism symptoms include feeding cessation, lethargy, paralysis and death.By referring to related literatures and patents, the best way for industrial production is selected, which bears the advantages of simple operation, mild conditions and high yield. At the same time, we optimized the corresponding reaction conditions of three important intermediate of chlorantraniliprole to get the best yield.The experiment was divided into three stages with ten steps. In the process of synthesis of 3-bromo-1-(3-chloro-2-pyridinyl)-1H-pyrazole-5-carboxylate(BCPPC) taking 3-bromo-1-(3-chloro-2-pyridinyl)-4,5-dihydro-1H-pyrazole-5-carboxylate (BCPDPC) as the material in the first stage, we developed the technology by means of orthogonal experiment. The optimal reaction conditions were as follows:the reaction temperature was 65℃, the reaction time was 4.5 h, the molar ratioes of BCPDPC to sulfuric acid and sulfuric acid to potassium persulfate were 0.5 and 0.75 respectively, the solvent was THF. We conducted several repeated tests, obtained the average yield of 90%.In the others stages, we optimized the reaction conditions of several important intermediates:isatins, anthranilic acid derivatives and oxazinones, by changing reaction conditions such as solvents, temperatures, molar ratioes, reaction times and so on. All the compounds were confirmed by 1H NMR, some others were aided by IR or elemental analysis.