Saturated five-membered heterocyclics, III.: Conversion of 1,3,4-oxadiazolidines into 1,2,4-triazolidines†

2,3,4,5-Alkyl substituted 1,3,4-oxadiazolidines have been converted into 1,2,3,4,5-substituted 1,2,4-triazolidines by reaction with a primary amine and a trace of acid as a catalyst. 2,3-Diethyl-1,3-oxazolidine gave on treatment with n-butylamine and acid, instead of the corresponding imidazolidine, ring cleavage to N-ethylaminoethanol and the Schiff base VII. The mechanism of these aminolyses is discussed.