(2S,5R)-3-(Azidomethyl)-3-methyl-7-oxo-4,4-dioxide-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic Acid Diphenylmethyl Ester is an intermediate in the synthesis of Tazobactam Sodium Salt-13C2,15N1 (T010102), which is the labelled analogue of Tazobactam Sodium Salt (T010100), which is a β-Lactamase inhibitor, used with β-lactam antibiotics to enhance their effect.