1H-pyrazolium, 5-hydroxy-3-(2-hydroxyethoxy)-4-(methoxycarbonyl)-1,1-dimethyl-, inner salt 3-(2-hydroxyethoxy)-4-(methoxycarbonyl)-1,1-dimethyl-1H-pyrazol-1-ium-5-olate InChI=1/C9H14N2O5/c1-11(2)8(13)6(9(14)15-3)7(10-11)16-5-4-12/h12H,4-5H2,1-3H