61553-61-5Relevant articles and documents
Acid-Catalyzed Ring-Chain Tautomerism in 1,3-Diazolidines
Lambert, Joseph B.,Wang, Gen-tai,Huseland, Dave E.,Takiff, Larry C.
, p. 68 - 71 (1987)
Ring-chain tautomerism has been studied in 2-substituted and 1,3-disubstituted diazolidines.In trifluoroacetic acid, these heterocycles are in equilibrium with the open-chain iminium ion.For materials lacking 2 substitution, 5-10percent of the chain form is present at room temperature.Because of resonance stabilization of the positive charge, 2-aryl-substituted systems have about 30percent of the chain form.All of these ring and chain forms undergo interconversion on the NMR time scale with a free energy of activation of 16 - 18 kcal/mol.