InChI=1S/C19H16N2O2/c20-12-17(18(22)15-6-7-15)19(23)21-16-10-8-14(9-11-16)13-4-2-1-3-5-13/h1-5,8-11,15,22H,6-7H2,(H,21,23)/b18-17-