Synthesis and structural study of 6-amino-1,4,6,7-tetrahydroimidazo[4,5-b]pyridin-5-ones

6-Amino-1,4,6,7-tetrahydroimidazo[4,5-b]pyridin-5-ones are new heterocyclic scaffolds which can be used as conformationally restricted His analogues and as modified purines. We have prepared imidazopiperidones 7 using N-α-acetyl-4-nitrohistidine methyl ester as the starting material. NMR studies and molecular modelling calculations on a surrogate of the His-Gly dipeptide 10 are also commented.