Dicaine hydrochloride is a highly effective local anesthetic that reversibly blocks nerve function. It is clinically used for infiltration anesthesia, nerve block anesthesia, epidural anesthesia, etc. Compared with procaine, its local anesthetic effect is significant and has been widely used in clinical practice. Research on existing synthesis routes has found that the synthesis of the intermediate p-butylaminobenzoic acid is a key step in the synthesis of tetracaine hydrochloride. However, this step has always had the drawbacks of unstable raw materials or low yields. Scientists have made improvements and improvements to this. In 1981, they proposed the alkylation reaction between p-aminobenzoic acid and 1-bromobutane to synthesize p-butylaminobenzoic acid. However, due to the inability to avoid the generation of byproducts from dibutylation and the unstable properties of the raw materials themselves, this route is not suitable for industrial production.