Legal status
Legal status
  • 7-chloro-5-(2,6-difluorophenyl)-1-methyl-1H-benzo[e] [1,4]diazepin-2(3H)-one
CAS Number
PubChem CID
Chemical and physical data
Molar mass320.72 g·mol−1
3D model (JSmol)
  • Fc3cccc(F)c3C2=NCC(=O)N(C)c1ccc(Cl)cc12
  • InChI=1S/C16H11ClF2N2O/c1-21-13-6-5-9(17)7-10(13)16(20-8-14(21)22)15-11(18)3-2-4-12(15)19/h2-7H,8H2,1H3

Difludiazepam[1] (Ro07-4065) is a benzodiazepine derivative which is the 2',6'-difluoro derivative of fludiazepam. It was invented in the 1970s but was never marketed, and has been used as a research tool to help determine the shape and function of the GABAA receptors, at which it has an IC50 of 4.1nM.[2][3][4] Difludiazepam has subsequently been sold as a designer drug, and was first notified to the EMCDDA by Swedish authorities in 2017.[5][6]

See also


  1. ^ Maskell PD, Wilson NE. Designer Benzodiazepines: New Challenges and Treatment Options, in Corazza O, Roman-Urrestarazu. Handbook of Novel Psychoactive Substances: What Clinicians Should Know about NPS. Taylor & Francis, 2019. ISBN 978-1-138-06830-8
  2. ^ Winkler DA, Burden FR, Watkins AJ (January 1998). "Atomistic Topological Indices Applied to Benzodiazepines using Various Regression Methods". Quantitative Structure-Activity Relationships. 17 (1): 14–19. doi:10.1002/(SICI)1521-3838(199801)17:01<14::AID-QSAR14>3.0.CO;2-U.
  3. ^ 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): 5246–5256. doi:10.1021/jm960536o. PMID 8978853.
  4. ^ 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): 715–724. doi:10.1021/jm00004a017. PMID 7861419.
  5. ^ Europol 2017 Annual Report on the implementation of Council Decision 2005/387/JHA (PDF). Lisbon, Portugal: European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) and Europol. 2018. ISBN 978-92-9497-348-1.
  6. ^ Manchester KR, Waters L, Haider S, Maskell PD (July 2022). "The blood-to-plasma ratio and predicted GABAA-binding affinity of designer benzodiazepines". Forensic Toxicology. 40 (2): 349–356. doi:10.1007/s11419-022-00616-y. PMC 9715504. PMID 36454409.