DL-Norephedrine hydrochloride

Chemical properties

white crystalline powder. soluble in water and alcohol, insoluble in ether, chloroform and benzene.

Originator

Propadrine, MSD ,US ,1941

The Uses of DL-Norephedrine hydrochloride

DL-Norephedrine is a psychoactive amphetamine that acts as a potent norepinephrine releasing agent (EC50 = 42-137 nM). It is less effective as a dopamine releasing agent (EC50 = 0.3-1.4 μM) and does not affect serotonin release. This product is intended for forensic and research applications.[Cayman Chemical]

Manufacturing Process

In one route as described in US Patent 2,151,517, 10.7 kg of technical benzaldehyde is vigorously agitated with a solution of 11.0 kg of sodium bisulfite in 50.0 liters of water until the formation of the addition-product is complete. Simultaneously, 8.25 kg of nitroethane is dissolved in a solution of 4.5 kg of caustic soda in 20.0 liters of water and the resultant warm solution is added with vigorous stirring to the magma of benzaldehyde sodium bisulfite. The mixture is agitated for 30 minutes and then allowed to stand overnight.
The aqueous portion of the mixture is now siphoned off from the supernatant layer of oily phenylnitropropanol and replaced with a fresh solution of 11.0 kg of sodium bisulfite in 50.0 liters of water. The mixture of phenylnitropropanol and bisulfite solution is now vigorously agitated for 15 minutes in order to remove and recover small amounts of unreacted benzaldehyde, and is then again allowed to stratify. This time, the phenylnitropropanol is siphoned off and filtered to remove a small amount of resinous material. The aqueous solution of sodium bisulfite remaining behind is reacted with benzaldehyde, as described above, thus making the process continuous.
The 1-phenyl-2-nitropropanol thus obtained is a colorless oil, specific gravity 1.14 at 20°C, odorless when pure, volatile with steam and boiling at 150° to 165°C under a pressure of 5 mm of mercury. It is soluble in alcohol, ether, acetone, chloroform, carbon tetrachloride, benzene and glacial acetic acid. The yield of 1-phenyl-2-nitropropanolobtained by this procedure is 17.1 to 17.7 kg.
It is hydrogenated and converted to the hydrochloride in subsequent steps. The hydrogen chloride has a melting point of 192°-194°C.
In an alternative route described in US Patent 3,028,429 propiophenone may be reacted with an alkyl nitrite to give isonitrosopropiophenone which is then hydrogenated and finally converted to the hydrochloride.

Therapeutic Function

Nasal decongestant, Anorexic

General Description

Phenylpropanolamine hydrochloride is an odorless white to creamy-white crystalline powder. Bitter taste. pH (3% solution):4.5-6. pH (10% solution) 4.2-5.5. (NTP, 1992)

Air & Water Reactions

Water soluble.

Reactivity Profile

DL-Norephedrine hydrochloride is incompatible with strong oxidizing agents.

Hazard

Poison by ingestion.

Fire Hazard

Flash point data for DL-Norephedrine hydrochloride are not available; however, DL-Norephedrine hydrochloride is probably combustible.

Safety Profile

Poison by ingestion, subcutaneous, intravenous, intraperitoneal, and intramuscular routes. An experimental teratogen. When heated to decomposition it emits very toxic fumes of HCl and NOx. Used as a raw material in cold and diet tablets.