Ropinirole Open Ring Nitro Impurity

2-[2-Methyl-4-oxo-6, 7, 8, 9-tetrahydro-4H-pyrido[1, 2-a] pyrimidin-3-yl] ethyl 4-(6-fluoro-1, 2-benzisoxazol-3-yl)piperidin-1-carboxylate ;