4-[(2-bromoacryloyl)amino]-2-[[5-carbamoyl-1-ethyl-1,6-dihydro-2-hydroxy-4-methyl-6-oxo-3-pyridyl]azo]benzenesulphonic acid

2-[[[5-(Aminocarbonyl)-1-ethyl-1,6-dihydro-2-hydroxy-4-methyl-6-oxopyridin]-3-yl]azo]-4-[(2-bromo-1-oxo-2-propenyl)amino]benzenesulfonic acid