InChI=1S/C16H20N2O2/c1-10(2)6-7-11-4-3-5-14-15(11)12(9-18-14)8-13(17)16(19)20/h3-6,9,13,18H,7-8,17H2,1-2H3,(H,19,20)/t13-/m0/s1