Ro07-3953

Ro07-3953
Legal status
Legal status	CA: Schedule IV; DE: NpSG (Industrial and scientific use only); UK: Under Psychoactive Substances Act;
Identifiers
	IUPAC name 7-chloro-5-(2,6-difluorophenyl)-1H-benzo[e][1,4]diazepin-2(3H)-one;
CAS Number	28910-86-3;
PubChem CID	23275763;
ChemSpider	10441869;
ChEMBL	ChEMBL151574;
CompTox Dashboard (EPA)	DTXSID10877922 ;
Chemical and physical data
Formula	C15H91ClF2N2O
Molar mass	389.35 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES C1C(=O)NC2=C(C=C(C=C2)Cl)C(=N1)C3=C(C=CC=C3F)F;
	InChI InChI=1S/C15H9ClF2N2O/c16-8-4-5-12-9(6-8)15(19-7-13(21)20-12)14-10(17)2-1-3-11(14)18/h1-6H,7H2,(H,20,21); Key:WENMWXYJTWETRE-UHFFFAOYSA-N;

Ro07-3953 (Diflunordazepam) is a benzodiazepine derivative which is the 2',6'-difluoro derivative of nordazepam. It was invented in the 1970s but was never marketed,^[1]^[2] however it has recently appeared on the market as a designer drug, first reported in Sweden in December 2024.^[3]^[4]

References

^ 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.
^ 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.
^ "EU Early Warning System – Formal Notification: EU‑EWS‑RCS‑FN‑2024‑0044 (Ro 07‑3953)" (PDF). EU Early Warning System (EWS) / EUDA. 16 December 2024.
^ "European Drug Report 2025 – Full Book" (PDF). European Union Drugs Agency (euda.europa.eu). 6 June 2025.

[1] 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.

[2] 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.

[3] "EU Early Warning System – Formal Notification: EU‑EWS‑RCS‑FN‑2024‑0044 (Ro 07‑3953)" (PDF). EU Early Warning System (EWS) / EUDA. 16 December 2024.

[4] "European Drug Report 2025 – Full Book" (PDF). European Union Drugs Agency (euda.europa.eu). 6 June 2025.

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[2]

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[4]

v t e Benzodiazepines
1,4-Benzodiazepines	2-Oxoquazepam 3-Hydroxyphenazepam Bromazepam BMS-906024* Camazepam Carburazepam Chlordiazepoxide Cinazepam Cinolazepam Clonazepam Cloniprazepam Clorazepate Cyprazepam Delorazepam Demoxepam Desmethylflunitrazepam Devazepide* Diazepam Diclazepam Difludiazepam Doxefazepam Elfazepam Ethyl carfluzepate Ethyl dirazepate Ethyl loflazepate Flubromazepam Fletazepam Fludiazepam Flunitrazepam Flurazepam Flutemazepam Flutoprazepam Fosazepam Gidazepam Halazepam Iclazepam Irazepine* Kenazepine Ketazolam Lorazepam Lormetazepam Lufuradom* Meclonazepam Medazepam Menitrazepam Metaclazepam Motrazepam N-Desalkylflurazepam Nifoxipam Nimetazepam Nitemazepam Nitrazepam Nitrazepate Nordazepam Nortetrazepam Oxazepam Phenazepam Pinazepam Pivoxazepam Prazepam Proflazepam Quazepam QH-II-66 Reclazepam RO4491533* Ro05-4082 Ro5-4864* Ro07-5220 Ro07-9749 Ro20-8065 Ro20-8552 SH-I-048A Sulazepam Temazepam Tetrazepam Tifluadom* Timelotem* Tolufazepam Triflunordazepam Tuclazepam Uldazepam
1,5-Benzodiazepines	Arfendazam Clobazam CP-1414S Lofendazam Triflubazam
2,3-Benzodiazepines*	Girisopam GYKI-52466 GYKI-52895 Nerisopam Talampanel Tofisopam
Triazolobenzodiazepines	Adinazolam Alprazolam Balovaptan* Bromazolam Clonazolam Estazolam Fluadinazolam Flualprazolam Flubromazolam Flunitrazolam Nitrazolam Phenazolam Pyrazolam Rilmazolam (active metabolite of Rilmazafone) Triazolam
Imidazobenzodiazepines	Bretazenil Climazolam EVT-201 FG-8205 Flumazenil GL-II-73 Imidazenil ¹²³I-Iomazenil L-655,708 Loprazolam Midazolam PWZ-029 Remimazolam Ro15-4513 Ro48-6791 Ro48-8684 Ro4938581 Sarmazenil SH-053-R-CH3-2′F
Oxazolobenzodiazepines	Cloxazolam Flutazolam Haloxazolam Mexazolam Oxazolam
Thienodiazepines	Bentazepam Clotiazepam Ro09-9212
Thienotriazolodiazepines	α-Hydroxyetizolam Apafant* Brotizolam Ciclotizolam Clotizolam Deschloroclotizolam Deschloroetizolam Etizolam Flubrotizolam Fluclotizolam Fluetizolam Israpafant* JQ1* Metizolam
Thienobenzodiazepines*	Olanzapine Telenzepine
Pyridodiazepines	Lopirazepam
Pyridotriazolodiazepines	Zapizolam
Pyrazolodiazepines	Razobazam* Ripazepam Zolazepam Zomebazam Zometapine*
Pyrrolodiazepines	Premazepam
Tetrahydroisoquinobenzodiazepines	Clazolam
Pyrrolobenzodiazepines*	Anthramycin
Benzodiazepine prodrugs	Alprazolam triazolobenzophenone Avizafone Rilmazafone
* atypical activity profile (not GABA_A receptor ligands)

See also

References