反应详情

温度

140 °C

Concentrated sulfuric acid (25 ml), boric acid (2.22 g, 35.6 mmol), iron (II) sulfate heptahydrate (831 mg, 2.99 mmol) and 3-nitrobenzene sulfonic acid sodium salt (7.25 g, 32.2 mmol) were stirred in a flask cooled with an ice-bath; glycerol (8.4 ml, 23 mmol) and 7-fluoro-2,3-dihydro-1,4-benzodioxin-5-amine (3.9 g, 23 mmol) were added followed by water (25 ml). The reaction was heated at 140° C. for 3 h, then cooled to rt. The mixture was poured onto ice-water (100 ml) and filtered. The filtrate was basified to pH 8 with 6N sodium hydroxide (130 ml) and then stirred with ethyl acetate (300 ml) for 0.5 h. The mixture was then filtered through celite and the phases separated. The aqueous layer was extracted with ethyl acetate (3×300 ml), the combined organics washed with brine, dried on magnesium sulphate, filtered and reduced to afford a crude which dissolved in ethyl acetate and purified by filtration over a silica pad to afford the compound as a pale green solid (2.78 g, 60%).

1. temperaturecooled with an ice-bath
2. temperaturecooled to rt
3. additionThe mixture was poured onto ice-water (100 ml)
4. filtrationfiltered
5. filtrationThe mixture was then filtered through celite
6. customthe phases separated
7. extractionThe aqueous layer was extracted with ethyl acetate (3×300 ml)
8. washthe combined organics washed with brine
9. customdried on magnesium sulphate
10. filtrationfiltered
11. customto afford a crude which
12. filtrationpurified by filtration over a silica pad