1-((4-(Fluorosulfonyl)benzoyl)oxy)-2,5-dioxo-3-pyrrolidinesulfonic acid 142439-47-2 3-Pyrrolidinesulfonic acid, 1-((4-(fluorosulfonyl)benzoyl)oxy)-2,5-dioxo- SSFSB Sulfo-N-succinimidyl-4-(fluorosulfonyl)benzoate