Title: Chlorcyclizine
CAS Registry Number: 82-93-9
CAS Name: 1-[(4-Chlorophenyl)phenylmethyl]-4-methylpiperazine
Additional Names: 1-(p-chloro-a-phenylbenzyl)-4-methylpiperazine; 1-(4-chlorobenzhydryl)-4-methylpiperazine; N-methyl-N¢-(4-chlorobenzhydryl)piperazine; chlorocyclizine
Manufacturers' Codes: compd 47-282
Trademarks: Alergicide; Perazyl; Trihistan
Molecular Formula: C18H21ClN2
Molecular Weight: 300.83
Percent Composition: C 71.87%, H 7.04%, Cl 11.79%, N 9.31%
Literature References: Prepn: Baltzly et al., J. Org. Chem. 14, 775 (1949); Murfitt, Dewing, GB 656043 (1951 to Wellcome Found.); US 2630435 (1953 to Burroughs Wellcome). Toxicity study: Castillo et al., J. Pharmacol. Exp. Ther. 96, 388 (1949).
Properties: Oil, bp0.1-0.15 137-145°.
Boiling point: bp0.1-0.15 137-145°
Derivative Type: Hydrochloride
CAS Registry Number: 1620-21-9
Manufacturers' Codes: AH-289
Trademarks: Di-Paralene (Abbott); Perazil (Burroughs Wellcome); Histantin (Burroughs Wellcome)
Molecular Formula: C18H21ClN2.HCl
Molecular Weight: 337.29
Percent Composition: C 64.10%, H 6.57%, Cl 21.02%, N 8.31%
Properties: Crystalline powder, mp 226-227°. One gram dissolves in about 2 ml water, in 11 ml alc, in about 4 ml chloroform. Practically insol in ether, benzene.
Melting point: mp 226-227°
Derivative Type: Dihydrochloride
Molecular Formula: C18H21ClN2.2HCl
Molecular Weight: 373.75
Percent Composition: C 57.84%, H 6.20%, Cl 28.46%, N 7.50%
Properties: Prisms from alc + ether, mp 216-216.5°. Freely sol in water; sol in alc. Aq soln is acid to litmus. LD50 i.p. in mice: 137 mg/kg (Castillo).
Melting point: mp 216-216.5°
Toxicity data: LD50 i.p. in mice: 137 mg/kg (Castillo)
Derivative Type: Di[(tert-butyl)naphthalene sodium sulfonate]
Trademarks: Bexedan (Smit)
Molecular Formula: C18H21ClN2.2C14H15NaOS
Molecular Weight: 809.47
Percent Composition: C 68.25%, H 6.35%, Cl 4.38%, N 3.46%, Na 5.68%, O 3.95%, S 7.92%
Therap-Cat: Antihistaminic.
Therap-Cat-Vet: The hydrochloride as antihistaminic.
Keywords: Antihistaminic; Piperazines.
Chlordan(e) Chlordantoin Chlordecone Chlordimeform Chlorendic Anhydride

Systematic (IUPAC) name
Clinical data
AHFS/ International Drug Names
MedlinePlus a682619
Legal status Prescription only
Routes Oral
CAS number 82-93-9
ATC code R06AE04
PubChem CID 2710
ChemSpider 2609 YesY
Chemical data
Formula C18H21ClN2 
Mol. mass 300.826 g/mol
 YesY (what is this?)  (verify)

Chlorcyclizine (Di-Paralene, Mantadil, Pruresidine, Trihistan) is a first-generation antihistamine of the phenylpiperazine class marketed in the United States and certain other countries.[1][2][3] It is used primarily to treat allergy symptoms such as rhinitis, urticaria, and pruritus, and may also be used as an antiemetic.[1][2][3] In addition to its antihistamine effects, chlorcyclizine also has some anticholinergic, antiserotonergic, and local anesthetic properties.[4][5]