Sulfamethoxypyrazine Impurity

4-Amino-?N-?(3,?4-?dihydro-?3-?oxo-?2-?pyrazinyl)?benzenesulfonamide is an impurity of Sulfamethoxypyrazine (S699230), an antimalarial, and used in the synthesis of necrosulfonamide, a necroptosis inhibitor.