2157-52-0 4-07-00-01631 (Beilstein Handbook Reference) 9-Oximinofluorene 9H-Fluoren-9-one oxime 9H-Fluoren-9-one, oxime BRN 1871046 EINECS 218-471-8 FLUOREN-9-ONE, OXIME Fluorenone oxime Fluorenone-9-oxime NSC 1988