N-BOC-thiomorpholine-3-carboxylic acid ethyl ester is primarily used in organic synthesis and pharmaceutical research. It serves as a key intermediate in the preparation of various biologically active compounds. The BOC (tert-butoxycarbonyl) protecting group allows selective modification of the molecule, making it valuable in peptide synthesis and drug development. Its ethyl ester functionality enhances solubility and reactivity, facilitating its use in coupling reactions. This compound is often employed in the synthesis of thiomorpholine derivatives, which are explored for their potential therapeutic applications, including as enzyme inhibitors or receptor modulators. Its versatility makes it a useful building block in medicinal chemistry.