Title: Diphenylpyraline
CAS Registry Number: 147-20-6
CAS Name: 4-(Diphenylmethoxy)-1-methylpiperidine
Additional Names: diphenylpyrilene; 4-benzhydryloxy-N-methylpiperidine; 1-methyl-4-piperidyl benzhydryl ether; 1-methyl-4-hydroxypiperidine benzhydryl ether
Manufacturers' Codes: P-253
Molecular Formula: C19H23NO
Molecular Weight: 281.39
Percent Composition: C 81.10%, H 8.24%, N 4.98%, O 5.69%
Literature References: Prepn: L. H. Knox, R. Kapp, US 2479843 (1949 to Nopco). Pharmacokinetics: G. Graham, A. G. Bolt, J. Pharmacokinet. Biopharm. 2, 191 (1974). Clinical trial in allergic rhinitis: H. Puhakka et al., J. Int. Med. Res. 5, 37 (1977). GC determn in blood and urine: H. Hattori et al., J. Chromatogr. 581, 213 (1992).
Derivative Type: Hydrochloride
CAS Registry Number: 132-18-3
Trademarks: Dayfen (3M Pharma); Diafen (3M Pharma); Hispril (SKB); Histryl (SKB); Histyn (Hsle); Kolton (Promonta); Lergoban (3M Pharma); Lergobine (3M Pharma)
Molecular Formula: C19H23NO.HCl
Molecular Weight: 317.85
Percent Composition: C 71.80%, H 7.61%, N 4.41%, O 5.03%, Cl 11.15%
Properties: Crystals from isopropanol + ether, mp 206°. Sol in water, ethanol, isopropanol. Practically insol in ether, benzene.
Melting point: mp 206°
Derivative Type: Hydrobromide
CAS Registry Number: 5807-87-4
Molecular Formula: C19H23NO.HBr
Molecular Weight: 362.30
Percent Composition: C 62.99%, H 6.68%, N 3.87%, O 4.42%, Br 22.05%
Literature References: Prepn: R. F. Phillips, US 2595405 (1952 to Merck & Co.).
Properties: Crystals, mp 201-202°. Soluble in water, ethanol.
Melting point: mp 201-202°
Derivative Type: 8-Chlorotheophyllinate
CAS Registry Number: 606-90-6
Additional Names: Piprinhydrinate; diphenylpyraline theoclate
Trademarks: Mepedyl (Glaxo)
Molecular Formula: C19H23NO.C7H7ClN4O2
Molecular Weight: 496.00
Percent Composition: C 62.96%, H 6.10%, N 14.12%, O 9.68%, Cl 7.15%
Literature References: Prepn: W. A. Schuler, DE 934890 (1955 to Promonta), C.A. 52, 20065i (1958).
Properties: White to off-white crystalline powder, mp 174-176°. Sparingly sol in water. Freely sol in alcohol.
Melting point: mp 174-176°
Therap-Cat: Antihistaminic.
Keywords: Antihistaminic; Aminoalkylethers.
Diphetarsone Diphosgene Dipicrylamine Dipin Dipipanone

Systematic (IUPAC) name
Clinical data
AHFS/Drugs.com International Drug Names
Legal status Prescription only
Routes Oral, Topical
Pharmacokinetic data
Half-life 24-40 hours[1]
CAS number 147-20-6 YesY
ATC code R06AA07
PubChem CID 3103
DrugBank DB01146
ChemSpider 2992 YesY
UNII 33361OE3AV YesY
KEGG D07862 YesY
ChEBI CHEBI:59788 YesY
Synonyms 4-(diphenylmethoxy)-1-methyl-piperidine
Chemical data
Formula C19H23NO 
Mol. mass 281.392 g/mol
 YesY (what is this?)  (verify)

Diphenylpyraline (DPP; sold as Allergen, Arbid, Belfene, Diafen, Hispril, Histyn, Lergobine, Lyssipol, Mepiben, Neargal) is a first-generation antihistamine with anticholinergic effects of the diphenylpiperidine class.[2][3][4] It is marketed in Europe for the treatment of allergies.[2][3][5] DPP has also been found to act as a dopamine reuptake inhibitor and produces hyperactivity in rodents.[6] It has been shown to be useful in the treatment of Parkinsonism.[7]