Tolazoline

Priscoline,Ciba,US,1948

Tolazoline is used for treating stable forms of pulmonary hypertension in newborns, and in cases where systemic arterial oxygenation cannot be achieved in the usual manner under careful observation of professionals.

Reactant for synthesis of imidazoline-containing drug

ChEBI: A member of the class of imidazoles that is 4,5-dihydro-1H-imidazole substituted by a benzyl group.

The phenyl-acetiminoether hydrochloride of the formula from 12 parts of benzylcyanide and ethanol and HCl is mixed with 8 parts of ethylenediamine hydrate which has been diluted with little alcohol, whereby the crystals go into solution. The whole is then heated on the water-bath until the ammonia odor has disappeared, cooled, concentrated caustic potash solution added, and the separated oil extracted with ether. The solution is dried with potassium carbonate and potassium hydroxide. After evaporation a pale oil is left which distills at 147°C under a pressure of 9 mm and which solidifies in the condenser to a white crystalline mass. The yield amounts to 90% of the theory. The hydrochloride melts at 168° to 170°C.

Vasodilator

2-Benzylimidazoline is an active vasodilator.

Tolazoline is a weak, reversible α-adrenoblocker that lowers resistance of peripheral blood vessels and elevates venous capacity. However, it also exhibits β-adrenomimetic activity, which consists of the stimulation of cardiac work and is manifest as tachycardia, cholinergic activity, which consists of stimulation of the gastrointestinal tract, and histamine-like activity, which consists of stimulation of gastric secretion.

Poison by ingestion,intraperitoneal, and intravenous routes. Mutation data reported. When heated to decomposition it emits toxicfumes of NOx.

Tolazoline, 2-benzyl-2-imidazoline (12.2.7), is synthesized by the heterocyclation of the ethyl ester of iminophenzylacetic acid with ethylendiamine (12.2.6), which forms the desired product (12.2.7) [32¨C35]. The structure of tolazoline is strikingly similar to |á-adrenergic agonists, which are antiedema sympathomimetics.