反应详情

温度

0 °C

To an ice-cold flask with a rubber stopper were added 2-hydroxy-5-(2-methoxy-pyridin-3-yl)-benzaldehyde (22.35 g, 0.0975 mol) and 3,4-diamino-benzoic acid (17.2 g, 0.113 mol) and the solid mixture was stirred at 0° C. for 15 min. Then DMA (120 mL) was added into the mixture via a syringe and the resulting solution was stirred at 0° C. for 2 h, and at the room temperature for 3 h. The rubber stopper was removed and the reaction mixture was stirred at 110° C. for 14 h open to the air. The DMA was removed under reduced pressure and the residue was mixed with 200 mL EtOAc, and sonicated for 15 min. The mixture was filtered to get the solid precipitate, which was mixture with 150 mL EtOAc, and sonicated for 5 min. The resulting mixture was filtered to get the solid crude that was dried at 40° C. for 6 h under reduced pressure to afford a mixture of the title compound and DMA (ratio 1:1) (16.15 g, 38%). 1H NMR (DMSO-d4) δ 3.92 (s, 3H), 7.14 (m, 1H), 7.15 (s, 1H), 7.64 (d, J=6 Hz, 1H), 7.74 (d, J=6 Hz, 1H), 7.84 (d, J=6 Hz, 1H), 7.91 (d, J=6 Hz, 1H), 8.19 (d, J=6 Hz, 1H), 8.21 (d, J=6 Hz, 1H), 8.29 (s, 1H). DMA also shows as 61.96 (s, 3H), 2.79 (s, 3H) and 2.94 (s, 3H). ESI-MS m/z 362.5 (MH+).

1. stirringthe resulting solution was stirred at 0° C. for 2 h
2. waitat the room temperature for 3 h
3. customThe rubber stopper was removed
4. stirringthe reaction mixture was stirred at 110° C. for 14 h open to the air
5. customThe DMA was removed under reduced pressure
6. additionthe residue was mixed with 200 mL EtOAc
7. customsonicated for 15 min
8. filtrationThe mixture was filtered
9. customto get the solid precipitate, which
10. customsonicated for 5 min
11. filtrationThe resulting mixture was filtered
12. customto get the solid crude that
13. customwas dried at 40° C. for 6 h under reduced pressure
14. customto afford