(2S,5R,6R)-6-Bromo-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid 26631-90-3 6-Bromopenicillanic acid Brobactam Brobactam [INN] Brobactamum [Latin] EINECS 247-856-3