To a solution of 3-(3-(4-methoxybenzyl)-6,7,8,9-tetrahydro-3H-pyrazolo[3,4-c][2,7]naphthyridine-7-carboxamido)benzoic acid (0.037 g, 80 μmol), isoxa-3-ylamine (8.8 μL, 120 μmol) and Hunig's Base (71 μL, 400 μmol) in dimethylacetamide (1 mL) and dichloromethane (1 mL) was added 2-chloro-1,3-dimethylimidazolinium chloride (DMC, 0.041 g, 240 μmol). The reaction mixture was shaken at room temperature for 16 hours followed by addition of water (2 mL) and dichloromethane (4 mL) were added. The organic layer was separated and the solvent removed under reduced pressure to give the desired product, N-(3-(isoxazol-3-ylcarbamoyl)phenyl)-3-(4-methoxybenzyl)-8,9-dihydro-3H-pyrazolo[3,4-c][2,7]naphthyridine-7(6H)-carboxamide. LCMS [M+H]: 524. The crude product was used in the next step without any further purification.
