反应详情

Crude 4-amino nicotinic acid (2.72 g, 11.4 mmol) in formamide (20 mL) is heated to 170° C. for 12 h. The volatiles are distilled out under reduced pressure (0.8 mmHg). The residual solid is then purified on a medium pressure silica gel column, eluting with 10% MeOH in CHCl3 to give 3H-pyrido[4,3-d]pyrimidin-4-one (780 mg, 47%) as a whitish yellow solid. 1H NMR (DMSO) δ 12.64 (1H, brs), 9.28 (1H, s), 8.83 (1H, d, J=5.5 Hz), 8.30 (1H, s), 7.58 (1H, d, J=5.8 Hz).

1. distillationThe volatiles are distilled out under reduced pressure (0.8 mmHg)
2. customThe residual solid is then purified on a medium pressure silica gel column
3. washeluting with 10% MeOH in CHCl3