W. Andrew Robinson

Pirenperone
Clinical data
Other names	R-47456; R-50656; Pirenpirone
Identifiers
	IUPAC name 3-[2-[4-(4-Fluorobenzoyl)piperidin-1-yl]ethyl]-2-methylpyrido[1,2-a]pyrimidin-4-one;
CAS Number	75444-65-4;
PubChem CID	4847;
ChemSpider	4681;
UNII	Y9FMC4513X;
KEGG	D05495;
ChEBI	CHEBI:92444;
ChEMBL	ChEMBL18331;
CompTox Dashboard (EPA)	DTXSID9045182 ;
ECHA InfoCard	100.071.081
Chemical and physical data
Formula	C23H24FN3O2
Molar mass	393.462 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES CC1=C(C(=O)N2C=CC=CC2=N1)CCN3CCC(CC3)C(=O)C4=CC=C(C=C4)F;
	InChI InChI=1S/C23H24FN3O2/c1-16-20(23(29)27-12-3-2-4-21(27)25-16)11-15-26-13-9-18(10-14-26)22(28)17-5-7-19(24)8-6-17/h2-8,12,18H,9-11,13-15H2,1H3; Key:HXCNRYXBZNHDNE-UHFFFAOYSA-N;

Pirenperone (INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name, BANTooltip British Approved Name; developmental code names R-47456, R-50656) is a serotonin receptor antagonist closely related to ketanserin and risperidone which is described as an antipsychotic and tranquilizer and was never marketed.^[1]^[2]

It is a relatively selective antagonist of the serotonin 5-HT_2A receptor and has been used in scientific research to study the serotonin system.^[3]^[2]^[4] Its affinities for serotonin and other receptors have been reported to be 1.1 nM for the serotonin 5-HT_2A receptor, 6.5 nM for the serotonin 5-HT₇ receptor, 20 nM for the α_1B-adrenergic receptor, 20 nM for the α_2B-adrenergic receptor, 61 nM for the serotonin 5-HT_2B receptor, 77 nM for the serotonin 5-HT_2C receptor, 485 nM for the serotonin 5-HT_1A receptor, and >1,000 nM for the serotonin 5-HT_1B receptor, whereas other receptors were not reported.^[3]

In the 1980s, the drug was found to block the effects of the lysergic acid diethylamide (LSD) in animals, and, along with ketanserin, led to the elucidation of the 5-HT_2A receptor as the biological mediator of the effects of serotonergic psychedelics.^[5]

References

^ Elks J (14 November 2014). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. pp. 994–. ISBN 978-1-4757-2085-3.
^ ^a ^b Morton IK, Hall JM (31 October 1999). Concise Dictionary of Pharmacological Agents: Properties and Synonyms. Springer Science & Business Media. pp. 223–. ISBN 978-0-7514-0499-9.
^ ^a ^b Casey AB, Cui M, Booth RG, Canal CE (June 2022). ""Selective" serotonin 5-HT2A receptor antagonists". Biochem Pharmacol. 200: 115028. doi:10.1016/j.bcp.2022.115028. PMC 9252399. PMID 35381208.
^ Colpaert FC, Balster R (6 December 2012). Transduction Mechanisms of Drug Stimuli. Springer Science & Business Media. pp. 29–. ISBN 978-3-642-73223-2.
^ Nichols DE (April 2016). "Psychedelics". Pharmacological Reviews. 68 (2): 264–355. doi:10.1124/pr.115.011478. PMC 4813425. PMID 26841800.