Concise Approach to the Synthesis of First Generation Anthranilic Diamide Insecticide, Chlorantraniliprole

An efficient and scalable process has been developed for the synthesis of anthranilic diamide insecticide i. e. chlorantraniliprole. The crucial step in this approach is the TiCl4-mediated aza-Fries rearrangement of aryl acetanilide to ortho-aminoaryl ketone. Another key step is the nucleophilic substitution of tosylate into the corresponding bromide using NaBr in the presence of TBAB. All the steps in this synthesis are carried out effectively on a gram scale with excellent yields. An efficient and practical approach for the synthesis of chlorantriniliprole has been accomplished in good to excellent yields from readily available starting materials i. e. 4-chloro-2-methylaniline and diethyl acetylenedicarboxylate.image