N-Hydroxyphthalimide → 2-[3-(2-propyl-1H-imidazo[4,5-c][1,5]naphthyridin-1-yl)propoxy]-1H-isoindole-1,3(2H)-dione

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Reaction Steps

Diisopropyl azodicarboxylate (8.10 mL, 48.4 inmol) was added dropwise over ten minutes to a stirred solution of 3-(2-propyl-1H-imidazo[4,5-c][1,5]naphthyridin-1-yl)propan-1-ol (10.9 g, 40.3 mmol), triphenylphosphine (12.7 g, 48.4 mmol), and N-hydroxyphthalimide (7.89 g, 48.4 mmol) in tetrahydrofuran (160 mL) at 0° C. The reaction was allowed to warm to room temperature and was stirred overnight. The solvent was removed under reduced pressure to afford an oil that was dissolved in ethyl acetate (200 mL) and extracted with 2 M HCl (3×100 mL). The aqueous layers were combined, and the pH was adjusted to 7 with the addition of solid sodium bicarbonate. A precipitate formed, was isolated by filtration, and was dissolved in dichloromethane (300 mL). The solution was dried over magnesium sulfate, filtered, and concentrated under reduced pressure to afford 17.38 g of 2-[3-(2-propyl-1H-imidazo[4,5-c][1,5]naphthyridin-1-yl)propoxy]-1H-isoindole-1,3(2H)-dione as a tan solid.

Provenance & Evidence