Preparation method of intermediate containing halogenated benzene ring side-chain flubendiamide structure

The invention discloses a preparation method of an intermediate containing a halogenated benzene ring side-chain flubendiamide structure, comprising the following steps: adding 3-iodophthalic acid, toluene and p-methylbenzene sulfonic acid to obtain a 3-iodophthalic anhydride solution; adding triethylamine, cooling, dropwise adding a DMAC solution of 2-methyl-1-methylthiopropylamine to obtain 3-iodine-N-(1,1-dimethyl-2-methylthioethyl)carbamoylbenzoic acid and an isomer solution thereof; adding a dilute sulfuric acid solution, heating, and stirring to obtain 3-iodine-N-(1,1-dimethyl-2-methylthioethyl)carbamoylbenzoic acid and an isomer thereof; and adding a hydrochloric acid solution and heating to 60-80 DEG C and then carrying out thermal insulation for 1-3h, completing the hydrolysis ofthe isomer, cooling to 0-20 DEG C, and carrying out suction filtration to obtain the finished product 3-iodine-N-(1,1-dimethyl-2-methylthioethyl) carbamoylbenzoic acid. By the preparation method of the intermediate containing