(E)-2-(2-(5-Methyl-[1,2,4]triazolo[1,5-a]pyridin-2-yl)vinyl)-[1,2,4]triazolo[5,1-f][1,6]naphthyridine → 2-(2-(5-Methyl-[1,2,4]triazolo[1,5-a]pyridin-2-yl)ethyl)-5,6-dihydro-[1,2,4]triazolo[5,1-f][1,6]naphthyridine

To a solution of (E)-2-(2-(5-methyl-[1,2,4]triazolo[1,5-a]pyridin-2-yl)vinyl)-[1,2,4]triazolo[5,1-f][1,6]naphthyridine (17 mg, 0.52 mmol) in MeOH (3 mL) and aqueous NaOH (1 N, 1 mL) was added 10% Pd/C (17 mg) under a nitrogen atmosphere. The reaction vessel was degassed for three times, followed by treatment with H2 for 1 h at room temperature. The mixture was then submitted for prep-HPLC purification to give a free base of the title compound as a white solid. The solid was triturated with a solution of HCl (gas) in EtOAc (2 mL) to afford the di-HCl salt of the title compound as a yellow solid (7.83 mg, yield 37%). ESI MS: m/z 332 [M+H]+.