InChI=1S/C18H18N2O3/c1-18-9-11-7-12(21)8-16(23-2)14(11)10-20(18)15-6-4-3-5-13(15)17(22)19-18/h3-8,21H,9-10H2,1-2H3,(H,19,22)/t18-/m0/s1