1H-pyrazolium, 4,5-dihydro-4-(methoxycarbonyl)-1,1-dimethyl-3-[2-[(methylsulfonyl)oxy]ethoxy]-5-oxo-, inner salt 4-(methoxycarbonyl)-1,1-dimethyl-3-{2-[(methylsulfonyl)oxy]ethoxy}-5-oxo-4,5-dihydro-1H-pyrazol-1-ium-4-ide InChI=1/C10H16N2O7S/c1-12(2)9(13)7(10(14)17-3)8(11-12)18-5-6-19-20(4,15)16/h5-6H2,1-4H