(2S,5R)-6-(Benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octane-2-carboxamide-d4 is the deuterated version of (2S,5R)-6-(Benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octane-2-carboxamide, an impurity of Avibactam (A794850). Avibactam is a a novel β-lactamase inhibitor.