4-(4-fluoro-3-(4-methoxypiperidine-1-carbonyl)benzyl)-5-nitrophthalazin-1(2H)-one → 5-amino-4-(4-fluoro-3-(4-methoxypiperidine-1-carbonyl)benzyl)phthalazin-1(2H)-one

Participants

Reaction Steps

4-(4-fluoro-3-(4-methoxypiperidine-1-carbonyl)benzyl)-5-nitrophthalazin-1 (2H)-one (45) (40 mg, 0.09 mmol) was added to 5% palladium on carbon (4 mg, 0.04 mmol) in ethanol (7 ml) at 25° C. under air. The resulting mixture was hydrogenated at 25° C. for 22 hours. The catalyst was filtered and washed with ethanol and the solvent evaporated to a pale brown gum. The crude product was purified by preparative HPLC (Waters XBridge Prep C18 OBD column, 5μ silica, 19 mm diameter, 100 mm length), using decreasingly polar mixtures of water (containing 1% NH3) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to afford the desired material as a beige solid (11 mg, 29.5% yield); 1H NMR (400.132 MHz, DMSO) δ 1.66-1.81 (2H, m), 1.86-1.96 (2H, m), 3.10-3.19 (1H, m), 3.36 (3H, s), 3.44-3.50 (2H, m), 3.55-3.64 (1H, m), 3.91-3.99 (1H, m), 4.08 (2H, s), 4.44 (2H, s), 6.99 (1H, d), 7.05-7.10 (1H, m), 7.23-7.28 (2H, m), 7.50-7.54 (1H, m), 7.94 (1H, d), 9.95 (1H, s); m/z (LC-MS, ESI+), RT=1.50 (M+H 411.3).

Provenance & Evidence