2H,8H-4-oxa-1-thia-9b-azacyclopenta[cd]phenalene-9-carboxylic acid, 6-fluoro-2a,3-dihydro-5-(4-methyl-1-piperazinyl)-8-oxo- 6-fluoro-5-(4-methylpiperazin-1-yl)-8-oxo-2a,3-dihydro-2H,8H-4-oxa-1-thia-9b-azacyclopenta[cd]phenalene-9-carboxylic acid InChI=1/C18H18FN3O4S/c1-20-2-4-21(5-3-20)14-11(19)6-10-13-16(14)26-7-9-8-27-17(22(9)13)12(15(10)23)18(24)25/h6,9H,2-5,7-8H2,1H3,(H,24,25