Legal status
Legal status
  • 5-(2-Fluorophenyl)-7-nitro-1,3-dihydro-1,4-benzodiazepin-2-one
CAS Number
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard100.018.072 Edit this at Wikidata
Chemical and physical data
Molar mass299.261 g·mol−1
3D model (JSmol)
  • FC1=C(C=CC=C1)C2=NCC(NC3=C2C=C(C=C3)[N+](=O)[O-])=O
  • InChI=1S/C15H10FN3O3/c16-12-4-2-1-3-10(12)15-11-7-9(19(21)22)5-6-13(11)18-14(20)8-17-15/h1-7H,8H2,(H,18,20)

Desmethylflunitrazepam (also known as norflunitrazepam, Ro05-4435 and fonazepam) is a benzodiazepine that is a metabolite of flunitrazepam[1][2][3] and has been sold online as a designer drug.[4][5] It has an IC50 value of 1.499 nM for the GABAA receptor.[6][7]

See also


  1. ^ Busker RW, van Henegouwen GM, Kwee BM, Winkens JH (May 1987). "Photobinding of flunitrazepam and its major photo-decomposition product N-desmethylflunitrazepam". International Journal of Pharmaceutics. 36 (2–3): 113–120. doi:10.1016/0378-5173(87)90145-1.
  2. ^ Coller JK, Somogyi AA, Bochner F (November 1998). "Quantification of flunitrazepam's oxidative metabolites, 3-hydroxyflunitrazepam and desmethylflunitrazepam, in hepatic microsomal incubations by high-performance liquid chromatography". Journal of Chromatography. B, Biomedical Sciences and Applications. 719 (1–2): 87–92. doi:10.1016/S0378-4347(98)00383-1. PMID 9869368.
  3. ^ Kilicarslan T, Haining RL, Rettie AE, Busto U, Tyndale RF, Sellers EM (April 2001). "Flunitrazepam metabolism by cytochrome P450S 2C19 and 3A4". Drug Metabolism and Disposition. 29 (4 Pt 1): 460–5. PMID 11259331.
  4. ^ Moosmann B, Bisel P, Franz F, Huppertz LM, Auwärter V (November 2016). "Characterization and in vitro phase I microsomal metabolism of designer benzodiazepines - an update comprising adinazolam, cloniprazepam, fonazepam, 3-hydroxyphenazepam, metizolam and nitrazolam". Journal of Mass Spectrometry. 51 (11): 1080–1089. Bibcode:2016JMSp...51.1080M. doi:10.1002/jms.3840. PMID 27535017.
  5. ^ Katselou M, Papoutsis I, Nikolaou P, Spiliopoulou C, Athanaselis S (2016). "Metabolites replace the parent drug in the drug arena. The cases of fonazepam and nifoxipam". Forensic Toxicology. 35 (1): 1–10. doi:10.1007/s11419-016-0338-5. PMC 5214877. PMID 28127407.
  6. ^ Maddalena DJ, Johnston GA (February 1995). "Prediction of receptor properties and binding affinity of ligands to benzodiazepine/GABAA receptors using artificial neural networks". Journal of Medicinal Chemistry. 38 (4): 715–24. doi:10.1021/jm00004a017. PMID 7861419.
  7. ^ So SS, Karplus M (December 1996). "Genetic neural networks for quantitative structure-activity relationships: improvements and application of benzodiazepine affinity for benzodiazepine/GABAA receptors". Journal of Medicinal Chemistry. 39 (26): 5246–56. doi:10.1021/jm960536o. PMID 8978853.