InChI=1S/C16H16N4O/c17-15(8-14-9-18-10-19-14)16(21)20-13-6-5-11-3-1-2-4-12(11)7-13/h1-7,9-10,15H,8,17H2,(H,18,19)(H,20,21)/t15-/m1/s1