InChI=1S/C15H20N2O4/c16-13(18)10-9-12(15(20)21)17-14(19)8-4-7-11-5-2-1-3-6-11/h1-3,5-6,12H,4,7-10H2,(H2,16,18)(H,17,19)(H,20,21)