This compound is commonly used in peptide synthesis as a protected form of the amino acid aminobutyric acid. The tert-butyl ester group (OtBu) acts as a protecting group for the carboxylic acid functionality, preventing unwanted reactions during the synthesis process. It is particularly useful in solid-phase peptide synthesis (SPPS) where selective deprotection is required to build complex peptide chains. The hydrochloride (HCl) form ensures stability and solubility in various reaction conditions. Its application is crucial in producing peptides for pharmaceutical research, drug development, and biochemical studies.