反应详情

1-Hydroxy-2,6-naphthyridine (550 mg) [prepared according to the method of Sakamoto, T. et al Chem, Pharm. Bull. 33, 626, (1985)] was stirred with phosphorous oxychloride (10 ml) at 110° for 5 h. The volatiles were removed in vacuo and the residue treated carefully with ice. After diluting with water (to ˜25 ml), solid NaHCO3 was added to effect neutralisation and the product extracted into EtOAc (2×80 ml). The combined organic extracts were dried (MgSO4), evaporated in vacuo, and the crude product chromatographed (SiO2; EtOAc) affording the title compound as a slightly yellow solid (420 mg, 68%). δH (CDCl3) 9.35 (1H, s), 8.82 (1H, d, J 5.9 Hz), 8.48 (1H, d, J 5.6 Hz), 8.00 (1H, d, J 5.9 Hz), 7.74 (1H, d, J 5.6 Hz); m/z (ES+, 70V) 165 and 167 (MH+).

1. customThe volatiles were removed in vacuo
2. additionthe residue treated carefully with ice
3. additionAfter diluting with water (to ˜25 ml), solid NaHCO3
4. additionwas added to effect neutralisation
5. extractionthe product extracted into EtOAc (2×80 ml)
6. dry with materialThe combined organic extracts were dried (MgSO4)
7. customevaporated in vacuo
8. customthe crude product chromatographed (SiO2; EtOAc)