反应详情

温度

60 °C

6-Hydroxynicotinic acid (20 g) in water (200 ml) and H2SO4 (80 ml) was heated to 90° C. for 1 hour. Potassium iodate (0.42 equivalent) and potassium iodide (0.96 equivalent) were both added portionwise over 2 hours. After a further hour at 90° C. the mixture was cooled to 60° C. and added to 1 kg of ice. The brown solid was filtered off, dried and taken up in DMF (30 ml)/EtOH(1 litre). Sodium metabisulfite was added until the brown colour disappeared and the mixture was poured onto ice (2 kg), a further 1.5 litre water added and the white solid filtered to give title compound (16.5 g). NMR δ(DMSO) 12.95 (1H, broad), 12.35 (1H, broad), 8.36 (1H, d), 8.03 (1H, d)

1. additionboth added portionwise over 2 hours
2. filtrationThe brown solid was filtered off
3. customdried
4. additionSodium metabisulfite was added until the brown colour
5. additionthe mixture was poured onto ice (2 kg)
6. additiona further 1.5 litre water added
7. filtrationthe white solid filtered