[2S-(2α,3β,5α)]-3-(Azidomethyl)-3-methyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic Acid Diphenylmethyl Ester-15N3 is an intermediate used in the synthesis of Tazobactam Sodium Salt-15N3 (T010103), which is a labeled analogue of Tazobactam Sodium Salt (T010100), a β-Lactamase inhibitor, used with β-lactam antibiotics to enhance their effect.