Abstract: | The antibiotic norfloxacin recrystallizes from acetonitrile as a dihydrate with the norfloxacin molecule in a zwitterionic form, i.e. 1‐ethyl‐6‐fluoro‐1,4‐dihydro‐4‐oxo‐7‐(1‐piperazin‐4‐io)‐3‐quinolinecarboxylate dihydrate, C16H18FN3O3·2H2O. |