Synonyms: 5-Thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylicacid, 3-[[[2-(aminocarbonyl)-5-methyl[1,2,4]triazolo[1,5-a]pyrimidin-7-yl]thio]methyl]-7-[[(2-amino-4-thiazolyl)[[2-[2-(3,4-dihydroxybenzoyl)hydrazino]-1,1-dimethyl-2-oxoethoxy]imino]acetyl]amino]-8-oxo-,monosodium salt, [6R-[6a,7b(Z)]]-;[1,2,4]Triazolo[1,5-a]pyrimidine,5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid deriv.; Ro 41-1879