L-Tyrosine benzyl ester p-toluenesulfonate salt is primarily used in peptide synthesis as a protected form of tyrosine. The benzyl ester group protects the carboxylic acid functionality, while the p-toluenesulfonate salt enhances solubility and stability. This compound is particularly valuable in solid-phase peptide synthesis, where it allows for the controlled incorporation of tyrosine into peptide chains without unwanted side reactions. Additionally, it is utilized in research to study enzyme-substrate interactions and in the development of pharmaceuticals targeting tyrosine-related pathways. Its protective groups can be selectively removed under mild conditions, making it a versatile intermediate in organic and medicinal chemistry.