Title: Clopenthixol
CAS Registry Number: 982-24-1
CAS Name: 4-[3-(2-Chloro-9H-thioxanthen-9-ylidene)propyl]-1-piperazineethanol
Additional Names: 2-chloro-9-[3-[4-(2-hydroxyethyl)-1-piperazinyl]propylidene]thiaxanthene
Molecular Formula: C22H25ClN2OS
Molecular Weight: 400.96
Percent Composition: C 65.90%, H 6.28%, Cl 8.84%, N 6.99%, O 3.99%, S 8.00%
Literature References: Thioxanthene neuroleptic. Prepn (configuration not specified): BE 585338; P. V. Petersen et al., US 3116291 (1960, 1963 both to Kefalas A/S). Prepn of the pharmacologically active cis-isomer: BE 816855; N. Lassen, US 3996211 (1974, 1976 both to Kefalas A/S). Pharmacology: Cazzullo, Andreola, Acta Neurol. 20, 162 (1965); Weissman, Mod. Probl. Pharmacopsychiatry 2, 15 (1969); Moeller Nielsen, ibid. 23. Metabolism: Khan, Acta Pharmacol. Toxicol. 27, 202 (1969). HPLC determn of isomers in serum: T. Aaes-Jorgensen, J. Chromatogr. 188, 239 (1980). Series of articles on pharmacology and clinical studies: Acta Psychiatr. Scand. 64, Suppl. 294, 1-77 (1981).
Properties: Colorless syrup. Sparingly sol in ether. Readily sol in methanol.
Derivative Type: Dihydrochloride
CAS Registry Number: 633-59-0
Manufacturers' Codes: AY-62021; N-746
Trademarks: Ciatyl (Troponwerke); Sordenac (Lundbeck); Sordinol (Ayerst)
Molecular Formula: C22H25ClN2OS.2HCl
Molecular Weight: 473.89
Percent Composition: C 55.76%, H 5.74%, Cl 22.44%, N 5.91%, O 3.38%, S 6.77%
Properties: Crystals from ethanol, mp 250-260° (dec). Freely sol in water; sparingly sol in alcohol. Practically insol in other organic solvents. LD50 in male mice (mg/kg): 111 i.v. (Lassen).
Melting point: mp 250-260° (dec)
Toxicity data: LD50 in male mice (mg/kg): 111 i.v. (Lassen)
Derivative Type: cis(Z)-Form
CAS Registry Number: 53772-83-1
Additional Names: a-Clopenthixol; zuclopenthixol
Properties: Crystals, mp 84-85°.
Melting point: mp 84-85°
Derivative Type: cis(Z)-Form dihydrochloride
CAS Registry Number: 58045-23-1
Trademarks: Cisordinol (Lundbeck); Clopixol (HMR)
Properties: Crystals, mp 250-260° (dec). LD50 in male mice (mg/kg): 105 i.v. (Lassen).
Melting point: mp 250-260° (dec)
Toxicity data: LD50 in male mice (mg/kg): 105 i.v. (Lassen)
Therap-Cat: Antipsychotic.
Keywords: Antipsychotic; Thioxanthenes.
Cloperastine Clopidogrel Clopidol Clopirac Cloprednol

Clopenthixol structure.svg
Systematic (IUPAC) name
(E,Z)-2-[4-[3-(2-chlorothioxanthen-9-ylidene) propyl]piperazin-1-yl]ethanol
Clinical data
Legal status  ?
Routes Oral
CAS number 982-24-1 N
ATC code N05AF02
PubChem CID 12454
ChemSpider 11945 N
KEGG D02613 N
Chemical data
Formula C22H25ClN2OS 
Mol. mass 400.965 g/mol
 N (what is this?)  (verify)

Clopenthixol (Sordinol), also known as clopentixol, is a typical antipsychotic drug of the thioxanthene class. It was introduced by Lundbeck in 1961.[1]

Clopenthixol is a racemic mixture of cis and trans isomers. Zuclopenthixol, the pure cis isomer, was later introduced by Lundbeck in 1962,[2] and has been much more widely used. Both drugs are equally effective as antipsychotics and have similar adverse effect profiles, but clopenthixol is half as active on a milligram-to-milligram basis and appears to produce more sedation in comparison.[3]

Clopenthixol is not approved for use in the United States.