5-[2-(Diethylamino)ethyl]-3-phenyl-1,2,4-oxadiazole citrate salt

Bredon,Organon

Oxolamine Citrate, is a antiinflammatory drug used as a cough suppressant.

18.7 g 3-chloro-propionyl chloride in 50 ml of dry ether was added dropwise with stirring to the cooled with ice solution 40 g of N-hydroxybenzamidine in 450 ml dry ester. A dense precipitate had fallen. The mixture was stirred 0.5 hour at room temperature and then was filtered off. The precipitate was thoroughly washed with water for a removal hydrochloride of starting Nhydroxybenzamidine whereas N-(amino)phenylmethylene-3-Cl-propionamide didnt solve. It was dried in vacuum over P2O5. Yield of clean product 94% from theoretical. MP: 98°-99°C. The solution of 9.2 g diethyl amine in 50 ml dry benzene was added dropwise to a suspension of above prepared N(amino)phenylmethylene-3-Cl-propionamide in dry benzene with stirring and cooling.
The mixture was warmed and stirred else 2 hours after adding. Then it was cooled, washed two times with water and dried over CaCl2. Then the solvent was removed. The residue was distilled in vacuum. Diethyl-[2-(3phenyl[1,2,4]oxadiasol-5)ethyl]amine (oxolamine) had BP: 127°C/0.4 mm. Yield 10.5 g.

Antitussive, Antiinflammatory

Poison by intraperitoneal route. Moderately toxic by ingestion. Experimental teratogenic and reproductive effects. Questionable carcinogen with experimental carcinogenic data. When heated to decomposition it emits toxic fumes of NOx. See also AMINES and other oxolamhe entries