(6R,7R)-7-[2-[2-(2-chloroacetamido)-4-thiazolyl]-2-syn-methoxy-iminoacetamido]-3-[[(2,5-dihydro-6-hydroxy-2-methyl-5-oxo-as-triazin-3-yl)thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid