(2S,5R,6R)-6-((R)-2-(4-Ethyl-2,3-dioxo-1-piperazinecarboxamido)-2-phenylacetamido)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid monohydrate 4-Thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid, 6-(((((4-ethyl-2,3-dioxo-1-piperazinyl)carbonyl)amino)phenylacetyl)amino)-3,3-dimethyl-7-oxo-, monohydrate, (2S-(2alpha,5alpha,6beta(S*))) 66258-76-2 Piperacillin Piperacillin [USAN]