(6R,7R)-7-[[2-[2-(aminomethyl)phenyl]acetyl]amino]-3-[[1-(carboxymethyl)tetrazol-5-yl]sulfanylmethyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid
7β-[2-(aminomethyl)phenyl]acetamido-3-{[1-(carboxymethyl)-1H-tetrazol-5-yl]sulfanyl}methyl-3,4-didehydrocepham-4-carboxylic acid