Usage?It is used to synthesize methyl p-sulfonyl chlorobenzopropionate. Aromatic sulfonyl chloride is an important pharmaceutical intermediate (synthetic sulfonamide drugs), which has a broad application prospect. The synthesis of p-sulfonyl chlorobenzopropionate by methyl phenylpropionate is simple and practical. The technical scheme adopted in the invention for the above purposes is as follows: the synthesis method of methyl sulfonyl chlorobenzopropionate is firstly esterified with phenylpropionate, then sulfonated with chlorosulfonic acid, then hydrolyzed, the solid is precipitated, dried, recrystallized and refined as the product.