4-[4-(2,6-Dimethoxypyrimidin-4-ylaminosulfonyl)phenylamino]-4-oxoisocrotonic acid

(Z)-4-[4-(2,6-Dimethoxypyrimidin-4-ylaminosulfonyl)phenylamino]-4-oxo-2-butenoic acid

4-[[4-[[(2,6-dimethoxy-4-pyrimidinyl)amino]sulphonyl]phenyl]amino]-4-oxoisocrotonic acid