Products of the Reaction of N,N'-Dibenzylethylenediamine and Glyoxal

Article abstract of DOI:10.1021/jo00213a032

The reaction of N,N'-dibenzylethylenediamine with glyoxal in ethanol has been shown to give 1,1',3,3'-tetrabenzyl-2,2'-biimidazolidine (5c) and trans-1,4,5,8-tetrabenzyl-1,4,5,8-tetraazadecalin (4c) in 60 : 40 ratio as the initial products.Compound 4c has been shown to undergo a reversible isomerization to the corresponding cis isomer 3c in CDCl3 and the ΔG⁰₃₃₃ for the isomerisation has been determined to be < 0.1 kcal/mol.Both 3c and 4c show dynamic behavior in their 1H and 13C NMR spectra.In 3c this dynamic process has a ΔG(excit.) of 13.0 kcal/mol and is ascribed to a ring flip process.In 4c the dynamic process has a ΔG(excit.) of 13.3 kcal/mol and is ascribed to slow nitrogen inversion.These results are compared and contrasted to the results obtained in the analogous methyl case.