Oxolamine is a cough suppressant.
The syntheses of 1,2,4-oxadiazole systems all rely on hydroxylamine for providing a preformed N-O linkage. The preparation of the respiratory anti-inflammatory and antitussive agent oxolamine starts by acylation of the alkoxide from the N-hydroxyamidine with 3-chloropropionyl chloride; the presence of the negative charge on oxygen results in the formation of the O-acylated product. Treatment of that intermediate with triethylamine leads to cyclization via imine formation to afford the 1,2,4-oxadiazole. Displacement of the terminal chlorine with diethylamine gives the corresponding amine oxolamine.