反应详情

温度

100 °C

To an ice-cooled stirred suspension of 2.70 g (6.20 mmol) 5-methoxy-2-phenyl-pyridin-4-ylamine in 3 ml distilled water was added dropwise 3 ml concentrated sulfuric acid and the mixture was then warmed to 100° C. 1.30 g (6.07 mmol) potassium iodate was added after 3 h, a further 1.30 g (6.07 mmol) potassium iodate was added after an additional 3 h, and finally a further 0.75 g (3.50 mmol) potassium iodate was added after an additional 3 h. Stirred was continued for a further 2.5 h at 100° C., and then the mixture was allowed to cool to room temperature on standing overnight. The mixture was then diluted with saturated brine, made basic by addition of 30% aq. sodium hydroxide solution, and extracted three times with tetrahydrofuran. The combined organic phases were dried over sodium sulfate and concentrated in vacuo. Flash chromatography (ethyl acetate/heptane) afforded 1.60 g (79%) 3-iodo-5-methoxy-2-phenyl-pyridin-4-ylamine as an orange oil which crystallized on standing. ES-MS m/e (%): 327 (M+H+, 100).

1. distillationdistilled water
2. additionwas added dropwise 3 ml concentrated sulfuric acid
3. stirringStirred
4. temperatureto cool to room temperature
5. waiton standing overnight
6. extractionextracted three times with tetrahydrofuran
7. dry with materialThe combined organic phases were dried over sodium sulfate
8. concentrationconcentrated in vacuo