反应详情

A suspension of 7c (0.5 g; 2.5 mmol) in glacial acetic acid/48% strength hydrobromic acid (1+1, 7 ml) was stirred under reflux for 6 h. The reaction mixture was cooled, added to H2O (20 ml) and adjusted to pH 2 using 10% strength Na2CO3 solution. The aqueous solution was extracted with diethyl ether (4×20 ml). The combined organic extract was washed with saturated NaCl solution (2×), dried over Na2SO4 and concentrated. On standing at room temperature, the off-brown oily residue (7d) crystallized out. The crystals were triturated with H2O, filtered off and dried.

1. temperatureunder reflux for 6 h
2. temperatureThe reaction mixture was cooled
3. extractionThe aqueous solution was extracted with diethyl ether (4×20 ml)
4. extractionThe combined organic extract
5. washwas washed with saturated NaCl solution (2×)
6. dry with materialdried over Na2SO4
7. concentrationconcentrated
8. customOn standing at room temperature
9. customthe off-brown oily residue (7d) crystallized out
10. customThe crystals were triturated with H2O
11. filtrationfiltered off
12. customdried