• 2-(4-Chlorophenyl)-5,6-dihydro-[1]benzothepino[5,4-c]pyridazin-3(2H)-one-7-oxide
CAS Number
PubChem CID
CompTox Dashboard (EPA)
Chemical and physical data
Molar mass356.82 g·mol−1
3D model (JSmol)
  • ClC1=CC=C(C=C1)N2N=C3C(CCS(C4=C3C=CC=C4)=O)=CC2=O
  • InChI=1S/C18H13ClN2O2S/c19-13-5-7-14(8-6-13)21-17(22)11-12-9-10-24(23)16-4-2-1-3-15(16)18(12)20-21/h1-8,11H,9-10H2 checkY
 ☒NcheckY (what is this?)  (verify)

Y-23684 is an anxiolytic drug with a novel chemical structure, which is used in scientific research.[1][2] It has similar effects to benzodiazepine drugs, but is structurally distinct and so is classed as a nonbenzodiazepine anxiolytic.

Y-23684 is a nonselective partial agonist at GABAA receptors. It has primarily anxiolytic and anticonvulsant effects, with sedative and muscle relaxant effects only appearing at higher doses. It produces little ataxia or potentiation of other sedatives such as ethanol or barbiturates when compared to the benzodiazepines diazepam and clobazam in animal tests.[3][4][5]

Y-23684 has a favourable pharmacological profile, producing strong anxiolytic and moderate anticonvulsant effects at low doses that cause little or no sedative side effects. It has been proposed for development for human medical use, but has not yet gone beyond animal tests.[6]


  1. ^ Nakao T, Obata M, Kawakami M, Morita K, Tanaka H, Morimoto Y, et al. (October 1991). "Studies on the synthesis of condensed pyridazine derivatives. IV. Synthesis and anxiolytic activity of 2-aryl-5,6-dihydro-(1)benzothiepino[5,4- c]pyridazin-3(2H)-ones and related compound". Chemical & Pharmaceutical Bulletin. 39 (10): 2556–63. doi:10.1248/cpb.39.2556. PMID 1687209.
  2. ^ Nakao T, Obata M, Yamaguchi Y, Marubayashi N, Ikeda K, Morimoto Y (January 1992). "Synthesis and biological activities of optical isomers of 2-(4-chlorophenyl)-5,6-dihydro-(1)benzothiepino[5,4-c]pyridazin-3(2H)-o ne 7-oxide". Chemical & Pharmaceutical Bulletin. 40 (1): 117–21. doi:10.1248/cpb.40.117. PMID 1349512.
  3. ^ Yakushiji T, Shirasaki T, Munakata M, Hirata A, Akaike N (July 1993). "Differential properties of type I and type II benzodiazepine receptors in mammalian CNS neurones". British Journal of Pharmacology. 109 (3): 819–25. doi:10.1111/j.1476-5381.1993.tb13648.x. PMC 2175650. PMID 8395299.
  4. ^ Yasumatsu H, Morimoto Y, Yamamoto Y, Takehara S, Fukuda T, Nakao T, Setoguchi M (April 1994). "The pharmacological properties of Y-23684, a benzodiazepine receptor partial agonist". British Journal of Pharmacology. 111 (4): 1170–8. doi:10.1111/j.1476-5381.1994.tb14868.x. PMC 1910153. PMID 7913372.
  5. ^ Griebel G, Perrault G, Sanger DJ (April 1999). "Differences in anxiolytic-like profile of two novel nonbenzodiazepine BZ (omega) receptor agonists on defensive behaviors of mice". Pharmacology, Biochemistry, and Behavior. 62 (4): 689–94. doi:10.1016/s0091-3057(98)00209-3. PMID 10208374. S2CID 9894109.
  6. ^ Griebel G, Perrault G, Tan S, Schoemaker H, Sanger DJ (September 1999). "Comparison of the pharmacological properties of classical and novel BZ-omega receptor ligands". Behavioural Pharmacology. 10 (5): 483–95. doi:10.1097/00008877-199909000-00007. PMID 10780255.