反应详情

温度

100 °C

To a solution of the product of Example 1 Step 1 (3.0 g, 17.9 mmol) in acetic acid (40 ml) was added bromine (3.12 g, 1 ml, 19.7 mmol) and the mixture was heated at 100° C. for 20 hours. After cooling the solvent was removed in vacuo and the residue was partitioned between dichloromethane and saturated sodium bicarbonate solution. The organic phase was washed with water (×3), dried and evaporated in vacuo. Purification of the residue by silica gel chromatography eluting with 50% dichloromethane in ethyl acetate afforded the title compound (1.9 g, 43%). 1H NMR (DMSO-d6) 8.73 (1H, s), 8.52 (1H, s), 7.0 (1H, br), 3.25 (2H, m), 1.16 (3H, t, J=7.2 Hz).

1. temperatureAfter cooling the solvent
2. customwas removed in vacuo
3. customthe residue was partitioned between dichloromethane and saturated sodium bicarbonate solution
4. washThe organic phase was washed with water (×3)
5. customdried
6. customevaporated in vacuo
7. customPurification of the residue by silica gel chromatography
8. washeluting with 50% dichloromethane in ethyl acetate