反应详情

Into a solution of 1 (0.150 g, 0.425 mmol) and THF (11 mL) was added 2M HCl (16 mL). The reaction was warmed to reflux. After refluxing 2 h, the reaction was allowed to cool to room temperature. A solid formed on standing. The reaction was cooled in an ice bath. The cold suspension was filtered. The filter pad was washed with water. The filtrate was concentrated in vacuo. The residue was suspended in water and filtered and combined with the original filter pad. The combined solids were stirred with a mixture of warm methanol and THF, adding more THF until the mixture became homogeneous. The homogeneous solution was concentrated in vacuo. The white residue was suspended in methanol and concentrated in vacuo four more times. The white residue was stirred with ether, filtered and the filter pad dried under a stream of nitrogen to give to give 2 (0.095 g, 79%) as a white solid: mp=240° C. (dec., begins turning dark then melts 260-261° C.). HPLC tR=5.33 min (100%, Condition C). 1H NMR (400 MHz, DMSO-d6) δ 12.18 (br. s., 1H), 11.69 (br. s., 1H), 7.98 (dd, J=2, 8 Hz, 1H), 7.81 (s, 1H), 7.46-7.54 (m, 1H), 6.97-7.10 (m, 2H), 2.86 (s, 3H). MS (ESI+) m/z 305.1 (M+Na)+, 283.1 (M+H)+, MS (ESI−)

1. temperatureThe reaction was warmed to reflux
2. temperatureAfter refluxing 2 h
3. customA solid formed
4. temperatureThe reaction was cooled in an ice bath
5. filtrationThe cold suspension was filtered
6. washThe filter pad was washed with water
7. concentrationThe filtrate was concentrated in vacuo
8. filtrationfiltered
9. additionadding more THF until the mixture
10. concentrationThe homogeneous solution was concentrated in vacuo
11. concentrationconcentrated in vacuo four more times
12. stirringThe white residue was stirred with ether
13. filtrationfiltered
14. customthe filter pad dried under a stream of nitrogen
15. customto give