2-10-00-00535 (Beilstein Handbook Reference) 2-Nitrofluorenone-5-carboxylic acid 42523-38-6 7-Nitro-9-fluorenone-4-carboxylic acid 7-Nitro-9-oxo-9H-fluorene-4-carboxylic acid 9H-Fluorene-4-carboxylic acid, 7-nitro-9-oxo- BRN 1994185