InChI=1/C17H14N2O4S/c20-17(18-21)9-5-4-6-14-10-12-15(13-11-14)19-24(22,23)16-7-2-1-3-8-16/h1-3,5,7-13,19,21H,(H,18,20)/b9-5+/f/h18H 4B58FB6A74360119