InChI=1S/C16H18N2O3/c1-15(2)9-7-8-5-4-6-10-11(8)16(21,14(20)18(10)3)12(9)13(19)17-15/h4-6,9,12,21H,7H2,1-3H3,(H,17,19)/t9-,12+,16?/m1/s1