Some years ago, we presented a simple synthetic approach to enone Mannich bases 2 via condensation of aromatic ketones 1 with paraformaldehyde (Scheme 1).[1] These enone Mannich bases could be condensed with a number of bifunctional nucleophiles [2] like amidines [3] or aminopyridines [4] in order to access the corresponding heterocyclic derivatives such as tetrahydropyrimidines or pyrido [1, 2-a] pyrimidines, some structures ...
