Manufacturing Process
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.