Β-Alanine tert-butyl ester hydrochloride is a protected form of the non-proteinogenic amino acid β-alanine. It is a white to off-white crystalline powder, commonly used as a key synthetic intermediate in organic and medicinal chemistry. The tert-butyl ester group serves as a robust protecting group for the carboxylic acid functionality, allowing for selective reactions on the amine group under various conditions. Its primary application is as a crucial building block in the synthesis of pharmaceutical compounds. It is notably employed in the preparation of β-lactam antibiotics, peptide mimetics, and other bioactive molecules where the β-alanine backbone is required. The hydrochloride salt form enhances its stability and handling properties. This compound is also utilized in the synthesis of certain polymers and as a reagent in chemical research. As a versatile intermediate, it facilitates the introduction of the β-amino acid moiety into more complex structures. Standard safety precautions for handling amino acid derivatives and hydrochloride salts should be observed, including the use of personal protective equipment to avoid inhalation or contact.