反应详情

温度

11 °C

The compound obtained in Example 16 (1 g) was dissolved in methanesulfonic acid (5 ml) with cooling at 10 to 12° C. and then treated dropwise with a solution of sodium nitrate (0.165 g) in methanesulfonic acid (2.5 ml). The mixture was stirred as it was for 2 hours, and then poured into a cool water, and the crystal precipitated was recovered by a filtration, washed with water and diisopropylether, dried in vacuo to obtain a crude crystal (1.04 g). This was suspended in ethyl acetate (15 ml) with stirring and then cooled on ice, and the crystal precipitated was recovered by a filtration, washed with a cool ethyl acetate to obtain the title compound (0.647 g, 59.5%).

1. customthe crystal precipitated
2. filtrationwas recovered by a filtration
3. washwashed with water and diisopropylether
4. customdried in vacuo
5. customto obtain a crude crystal (1.04 g)
6. stirringwith stirring
7. temperaturecooled on ice
8. customthe crystal precipitated
9. filtrationwas recovered by a filtration
10. washwashed with a cool ethyl acetate