3-(4-Bromo-3-oxobutanesulfonyl)-1-propionic acid 4-nitrophenyl ester 3-(4-Bromo-3-oxobutanesulfonyl)-1-propionic acid-4-nitrophenyl ester 76785-49-4 BSPNP Propanoic acid, 3-((4-bromo-3-oxobutyl)sulfonyl)-, 4-nitrophenyl ester