Sodium Sulfate → HCID 58846592, compound

Participants

Reaction Steps

To a stirred solution of (R)-2-(4-aminopiperidin-1-yl)-1-(6-methoxy-[1,5]naphthyridin-4-yl)ethanol (2f) (0.34 g, 1.13 mmole) in dichloroethane (10 mL) and dry ethanol (5 mL) at RT was added 7-oxo-5,6,7,8-tetrahydro-[1,8]naphthyridine-3-carboxaldehyde (113 g) (0.20 g, 1.13 mmole) and granular Na2SO4 (approximately 100 mg). After 72 h, the reaction was concentrated. The remaining residue was dissolved in dry ethanol and reacted with NaBH4 (0.043 g, 1.13 mmole). After 12 h at RT, the reaction was concentrated under vacuum and the residue was dissolved in a mixture of H2O (10 mL) and saturated aqueous NaHCO3 (50 mL). The aqueous solution was extracted with EtOAc (2×75 mL) and the combined organic phases were washed with brine then were dried over Na2SO4. Flash chromatography on silica gel (9:1 CHCl3/MeOH containing 5% NH4OH) afforded the title compound (0.11 g, 21%) as a white solid: 1H NMR (400 MHz, d6-DMSO) δ 10.43 (br s, 1H), 8.77 (d, J=4.5 Hz, 1H), 8.23 (d, J=9.0 Hz, 1H), 8.01 (s, 1H), 7.75 (d, J=4.5 Hz, 1H), 7.58 (s, 1H), 7.24 (d, J=9.0 Hz, 1H), 5.77 (m, 1H), 5.23 (br s, 1H), 4.02 (s, 3H), 3.63 (s, 2H), 3.38 (m, 2H), 3.11 (m, 1H), 2.83 (m, 2H), 2.65 (m, 1H), 2.47 (m, 2H), 2.32 (m, 1H), 2.17 (m, 1H), 1.79 (m, 2H), 1.27 (m, 2H); MS (ES) m/e 463 M+H)+.

Provenance & Evidence