Alprenolol

Description

Occupational cases of contact dermatitis caused by exposure to alprenolol have been reported within the pharmaceutical industry.

Originator

Aptol,Globopharm,Switz.

The Uses of Alprenolol

Antiadrenergic (β-receptor).

Definition

ChEBI: A secondary alcohol that is propan-2-ol substituted by a 2-allylphenoxy group at position 1 and an isopropylamino group at position 3. It is a beta-adrenergic antagonist used as a antihypertensive, anti-arrhythmia and a sympatholytic agent.

Manufacturing Process

A solution of 24.6 g of o-allyl-epoxypropoxybenzene dissolved in 250 ml of absolute ethanol saturated with ammonia was placed in an autoclave and heated on a steam-bath for 2 hours. The alcohol was then removed by distillation and the residue was redissolved in a mixture of methanol and ethylacetate. Hydrogen chloride gas was introduced into the solution. The hydrochloride salt was then precipitated by the addition of ether to yield 11.4 g of product. Five grams of the amine-hydrochloride thus formed were dissolved in 50 ml of methanol and 9 ml of acetone. The resulting solution was cooled to about 0°C. At this temperature 5 g of sodium borohydride were added over a period of 1 hour. Another 2.2 ml of acetone and 0.8 g of sodium borohydride were added and the solution was kept at room temperature for 1 hour, after which 150 ml of water were added to the solution. The solution was then extracted with three 100-ml portions of ether which were combined, dried over potassium carbonate, and evaporated. The free base was then recrystallized from petrol ether (boiling range 40-60°C) to yield 2.7 g of material having a melting point of 57°C.
The corresponding hydrochloride was prepared by dissolving 2 g of the product, prepared above, in 20 ml of acetone, and adding to the resulting solution acetone saturated with hydrogen chloride until the pH was reduced to about 3. The precipitated hydrochloride salt was then recrystallized from acetone.

Therapeutic Function

Beta-adrenergic blocker

Contact allergens

Occupational cases of contact dermatitis due to this betablocker were reported in the pharmaceutical industry