1,6-Naphthyridine → 1,2,3,4-Tetrahydro-1,8-naphthyridine

To a solution of 0.8315 g (6.39 mmol) 1,6-naphthyridine in 25 mL EtOH was added 0.0875 g Pd (10% on C). The reaction mixture was stirred under H2 at atmospheric pressure. After 24 h, an additional 0.0431 g Pd (10% on C) was added. After a total of 46 h under H2 at atmospheric pressure, the reaction mixture was diluted with 50 mL EtOH and filtered over celite. The celite was washed with 300 mL EtOH, and the filtrate concentrated in vacuo. Purification by flash chromatography (50×105 mm silica gel, linear gradient 5-10% (10% NH4H:MeOH):CH2Cl2) yielded 32. 1H NMR (CDCl3, 400 MHz) δ 7.969 (d, 2H, J=4.94 Hz, ArH); 6.279 (d, 1H, J=5.57 Hz, ArH); 3.361-3.326 (m, 2H, CH2); 2.703 (t, 2H, J=6.27 Hz, CH2); 1.962-1.903 (m, 2H, CH2); MS (Electrospray): m/z 134.9 (M+H).

1. filtrationfiltered over celite
2. washThe celite was washed with 300 mL EtOH
3. concentrationthe filtrate concentrated in vacuo
4. customPurification by flash chromatography (50×105 mm silica gel, linear gradient 5-10% (10% NH4H:MeOH):CH2Cl2)

ORD record

ord-21a926f21800491e96d0358057b29099

Source dataset

uspto-grants-2003_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06534510B2