Title: Etoperidone
CAS Registry Number: 52942-31-1
CAS Name: 2-[3-[4-(3-Chlorophenyl)-1-piperazinyl]propyl]-4,5-diethyl-2,4-dihydro-3H-1,2,4-triazol-3-one
Molecular Formula: C19H28ClN5O
Molecular Weight: 377.91
Percent Composition: C 60.39%, H 7.47%, Cl 9.38%, N 18.53%, O 4.23%
Literature References: Psychotropic drug related structurally to trazodone, q.v. Prepn: G. Palazzo, DE 2351739; idem, US 3857845 (both 1974 to Angelini). Pharmacology and acute toxicity: R. Lisciani et al., Arzneim.-Forsch. 28, 417 (1978); M. T. Ramacci et al., ibid. 29, 294 (1979). Clinical evaluation: P. Bertoletti, G. Clin. Med. 58, 393 (1977). Teratology study: S. Barcellona et al., Toxicology 8, 87 (1977). Acute cardiovascular toxicity study: R. Lisciani et al., ibid. 10, 151 (1978).
Properties: Liq, bp0.5 230°.
Boiling point: bp0.5 230°
Derivative Type: Hydrochloride
CAS Registry Number: 57775-22-1
Manufacturers' Codes: AF-1191; ST-1191
Trademarks: Axiomin (Promeco); Depracer (Lepori); Etoran (Il Dong); Staff (Sigma-Tau); Tropene (Degussa)
Molecular Formula: C19H28ClN5O.HCl
Molecular Weight: 414.37
Percent Composition: C 55.07%, H 7.05%, Cl 17.11%, N 16.90%, O 3.86%
Properties: Crystals from isopropanol, mp 197-198°. pH (2% aq soln): 4.1 ± 0.2. Sol in water, alc; slightly sol in chloroform. Practically insol in acetone, benzene, ether. LD50 in mice, rats (mg/kg): 580, 720 orally; 72, 62 i.v.; 135, 120 i.p. (Lisciani).
Melting point: mp 197-198°
Toxicity data: LD50 in mice, rats (mg/kg): 580, 720 orally; 72, 62 i.v.; 135, 120 i.p. (Lisciani)
Therap-Cat: Antidepressant.
Keywords: Antidepressant.
Etorphine Etoxazole Etozolin Etretinate Etrimfos

Systematic (IUPAC) name
Clinical data
Legal status Prescription only
Routes Oral
CAS number 52942-31-1
ATC code N06AB09
PubChem CID 40589
ChemSpider 37083 YesY
Synonyms ST-1191
Chemical data
Formula C19H28ClN5O 
Mol. mass 377.911 g/mol
 YesY (what is this?)  (verify)

Etoperidone (Axiomin, Centren, Depracer, Etonin, Etoran, Staff, Tropene), also known as clopradone and thozalinone, is an antidepressant of the phenylpiperazine class which was introduced in Europe in 1977.[1][2] It acts primarily as an antagonist of several receptors in the following order of potency: 5-HT2A receptor (36 nM) > α1-adrenergic receptor (38 nM) > 5-HT1A receptor (85 nM) > α2-adrenergic receptor (570 nM);[3] it has only very weak or negligible affinity for blocking the following receptors: D2 receptor (2,300 nM) > H1 receptor (3,100 nM) > mACh receptors (>35,000 nM).[3] In addition to its receptor blockade, etoperidone also has weak affinity for the monoamine transporters as well: serotonin transporter (890 nM) > norepinephrine transporter (20,000 nM) > dopamine transporter (52,000 nM).[4]