Chemical Properties
Colorless crystal or white crystalline powder. Soluble in benzene, ethanol, water, chloroform, slightly soluble in ether. Odorless, slightly bitter.
History
Antipyrine (phenazone) was one of the first important synthetic Analgesic drugs that synthesis in Germany in 1884 by a pupil of Emil Fischer.
Uses
Antipyrine has been used for immunoblotting. It has also been used as an internal reference marker for studying the transport characteristics of platinum-containing drug, cisplatin in the human placenta in vitro. Antipyrine is an analgesic and antipyretic that has been given by mouth and as ear drops. It is often used in testing the effects of other drugs or diseases on drug-metabolizing enzymes in the liver. (From Martindale, The Extra Pharmacopoeia, 30th ed, p29)
Definition
ChEBI: Antipyrine is a pyrazolone derivative that is 1,2-dihydropyrazol-3-one substituted with methyl groups at N-1 and C-5 and with a phenyl group at N-2. It has a role as a non-narcotic analgesic, an antipyretic, a non-steroidal anti-inflammatory drug, a cyclooxygenase 3 inhibitor, a xenobiotic and an environmental contaminant.
Preparation
Antipyrine (1) was prepared from the reaction of 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one with methyl iodide in methanol or in acetonitrile containing sodium bicarbonate in water in 58% yield. The reaction of 1-methyl-2-phenylhydrazine (2) with methyl 3-oxobutanoate (3) in acetonitrile gave 1 and pyrazolone 4 . Krohn has been reported the synthesis of 1 from the reaction of 5 with dimethyl sulfate in 71% yield. The reaction of pyrazolone 6 with methanol in the presence of triphenylphosphine afforded 1 (14%) and pyrazole 7 (53%). The same reaction was reported by Pegurier et al by heating the reactants in methanol containing calcium monoxide. Knorr early reported also, the synthesis of antipyrine from heating of 1-phenyl-5-ethoxy-3- methylpyrazole (8) with methyl iodide in methanol.
brand name
Aerol;Antigestin;Asthma dellipsoids;Aurafair;Auralgicin;Auraltone;Bajumol;Breezeazy;Calmasmin;Cetussan;Codalgin;Crema antisolar evanescente;Doleron novum;Dolo-med-much;Dol-stop;Kalopsis;Lanceotic;Lavylgan;Mig-antos;Migranin;Natt-lunedon;Neo-felsol;Orecil;Otipyrin;Otosan-sulfan;Otothricinol;Palacaine;Pasta antisola;Pomada heridas;Prednefrin;Prefrin liquifilm;Prefrin z;Priatan;Prophyllen;Remolmed;Salicopil;Sedaural;Sedonan;Shhe 21;Spalt n;Tympagesic;Visublefarite.
World Health Organization (WHO)
Phenazone is a pyrazolone derivative chemically related to
aminophenazone. Some regulatory authorities have imposed restrictions on its use
on these grounds. However, a recent international study showed no statisticallybased
evidence of an association with agranulocytosis or aplastic anaemia. Nor
does it share with aminophenazone the propensity to produce potentially
carcinogenic nitrosamines.
General Description
Antipyrine is an antipyretic agent used for the symptomatic treatment of acute otitis media, most commonly in combination with benzocaine. One of the earliest widely used analgesics and antipyretics, antipyrine was gradually replaced in common use by other medications including phenacetin (itself later withdrawn because of safety concerns), aspirin, paracetamol and modern NSAIDs such as ibuprofen.
Biochem/physiol Actions
Antipyrine also referred to as phenazone or phenazonum is an anti-inflammatory agent that possesses analgesic, antipyretic and platelet-inhibitory actions.
Safety Profile
A human Doison bv 1 i
an unspecified route. Moderately toxic via
ingestion, subcutaneous, and intravenous
routes. Questionable carcinogen with
experimental tumorigenic data. Mutation
data reported. When heated to
decomposition it emits toxic fumes of NOx.
Purification Methods
Antipyrine crystallises from EtOH/water mixture, *benzene, *benzene/pet ether or hot water (charcoal), and the crystals are dried under a vacuum. [Beilstein 24 H 27, 24 III/IV 75.]
