An approach to the synthesis of all possible tetrahydropyrido [d] pyridazinones has been developed. The method relies on the catalytic hydrogenation of the corresponding aromatic counterparts, which were obtained by cyclization of the relevant dibromomethyl-substituted pyridinecarboxylates with hydrazine. The synthetic schemes include 4–5 steps starting from commercially available materials. The tetrahydropyrido [d] pyridazinone scaffolds are ...