Nitrazepam

Chemical Properties

Pink Solid

Originator

Mogadan,Roche,W. Germany,1965

Uses

Anticonvulsant; hypnotic. Controlled substance (depressant)

Definition

ChEBI: A 1,4-benzodiazepinone that is 1,3-dihydro-2H-1,4-benzodiazepin-2-one which is substituted at positions 5 and 7 by phenyl and nitro groups, respectively. It is used as a hypnotic for the short-term management of insomnia and for the trea ment of epileptic spasms in infants (West's syndrome).

Manufacturing Process

A mixture of 16.8 g of 2 -aminobenzophenone, 11.9 g of glycine ethyl ester hydrochloride and 200 cc of pyridine was heated to reflux. After one hour, 20 cc of pyridine was distilled off. The solution was refluxed for 15 hours, then 11.9 g of glycine ethyl ester hydrochloride was added and the refluxing was continued for an additional 4 hours. The reaction mixture was continued for an additional 4 hours. The reaction mixture was concentrated in vacuo, then diluted with ether and water. The reaction product, 5-phenyl-3H-1,4- benzodiazepin-2(1H)-one, crystallized out, was filtered off, and then recrystallized from acetone in the form of colorless rhombic prisms, MP 182°C to 183°C.
48 g (0.2 mol) of 5-phenyl-3H-1 ,4-benzodiazepin-2(1 H)-one was dissolved in 250 cc of concentrated sulfuric acid by stirring at 15°C for ? hour. The solution was then cooled to 0°C and a mixture of 9.1 cc of fuming nitric acid (90%, sp. gr. = 1.50) and 11.8 cc of concentrated sulfuric acid was added dropwise with stirring, keeping the temperature of the reaction mixture between -5°C and 0°C. After completion of the addition of the nitric acidsulfuric acid mixture, stirring was continued for 1 hour and the reaction mixture was stored in the refrigerator overnight.
The mixture was then added dropwise to 2 kg of crushed ice with stirring and cooling, keeping the temperature at 0°C. After 1 hour of stirring in the cold, 640 cc of concentrated ammonium hydroxide was added dropwise at 0°C to pH 8. Stirring was continued for ? hour and the crude product was filtered off, washed with a small amount of ice water and sucked dry overnight. The crude product was suspended in a mixture of 100 cc of methylene chloride and 1,700 cc of alcohol. 50 g of decolorizing charcoal was added and the mixture was refluxed with stirring for 2 hours. After standing overnight at room temperature 15 g of diatomaceous earth filter aid was added and the refluxing was resumed for 1? hours. The mixture was filtered while hot. The clear, light yellow filtrate was concentrated in vacuo on the steam bath with stirring to about 600 cc. The concentrate was stirred and cooled in ice for about 2 hours; the precipitated crystalline product was filtered off, washed with some petroleum ether and sucked dry. The product, 7-nitro-5-phenyl-3H- 1,4-benzodiazepin-2(1H)-one, was recrystallized from a mixture of 1,000 cc of alcohol and 50 cc of methylene chloride to obtain white prisms melting at 224°C to 225°C.

brand name

Mogadon (HoffmannLaRoche).

Therapeutic Function

1,3-Dihydro-7-nitro-5-phenyl-2H-1,4-benzodiazepin-2-one

Clinical Use

Benzodiazepine:
Hypnotic

Safety Profile

Poison by intraperitoneal and intravenous routes. Moderately toxic by ingestion. Experimental reproductive effects. Mutation data reported. An anticonvulsant and hypnotic agent. When heated to decomposition it emits toxic fumes of NOx. See also DIAZEPAM.

Drug interactions

Potentially hazardous interactions with other drugs
Antibacterials: metabolism possibly increased by rifampicin.
Antipsychotics: increased sedative effects; risk of serious adverse effects in combination with clozapine.
Antivirals: concentration possibly increased by ritonavir.
Disulfiram: metabolism of nitrazepam inhibited, increased sedative effects.
Sodium oxybate: enhanced effects of sodium oxybate - avoid

Metabolism

Metabolised in the liver, mainly by nitroreduction followed by acetylation; none of the metabolites possess significant activity. Excreted in the urine mainly as metabolites.