(S)-Tert-butyl 2-aminopropanoate, also known as (S)-alanine tert-butyl ester, is widely used as a chiral building block in the synthesis of pharmaceuticals, particularly in the production of optically active compounds. It serves as a key intermediate in the preparation of various active pharmaceutical ingredients (APIs) where stereochemistry plays a critical role in biological activity.

This compound is employed in peptide synthesis as a protected form of alanine, with the tert-butyl ester group protecting the carboxylic acid to enable selective reactions, such as N-terminal coupling, during the formation of peptide bonds. The tert-butyl ester provides stability under various reaction conditions, making it a valuable tool in organic synthesis.

Additionally, it is utilized in the development of agrochemicals and fine chemicals, where its chiral nature contributes to the creation of more effective and selective products. Its application extends to research and development in asymmetric synthesis, aiding in the discovery of new compounds with potential therapeutic or industrial uses.