Used as a key intermediate in the synthesis of beta-lactam antibiotics, particularly third-generation cephalosporins such as cefotaxime, ceftriaxone, and cefepime, as well as some carbapenems. The tert-butoxycarbonyl (Boc) group serves as a protecting group for the 2-amino functionality on the thiazole ring, enabling selective acylation at the acetic acid moiety to attach the side chain to the beta-lactam core. This enhances the antibiotic's activity against Gram-negative bacteria. The Boc protection is compatible with the reaction conditions and can be removed under mild acidic conditions post-synthesis. Its thiazole structure contributes to improved pharmacokinetic properties in the final drugs.