InChI=1S/C21H28N4O2/c1-6-7-13-18(16(4)26)25-14-19(23-24-25)21(5,15(2)3)22-20(27)17-11-9-8-10-12-17/h6-12,14-15,18H,13H2,1-5H3,(H,22,27)/b7-6+/t18-,21+/m1/s1