4-Nitrobenzyl (R)-2-diazo-4-((2R,3S)-3-((R)-1-hydroxyethyl)-4-oxoazetidin-2-yl)-3-oxopentanoate is used as a reactant in the preparation of carbapenem compounds for treatment of bacterial infections. It is also the impurity of Meropenem (M225668), which is an ultra-broad spectrum injectable antibiotic used to treat a wide variety of infections, including meningitis and pneumonia.