反应详情

A mixture of the product of Step 3 (1.4 g, 3.1 mmol), in anhydrous CF3COOH (3 ml) was stirred for 24 h at room temperature under N2, than evaporated to dryness under reduced pressure. The residue was dried in vacuo for 1 h and suspended in H2O (10 ml) and the pH of the mixture was adjusted to ˜8 with NH4OH. This was filtered and filtrate was partially evaporated under reduced pressure. The precipitate formed was filtered off, washed with H2O, small volume of EtOH, Et2O and dried in vacuo to give pure product as a deep yellow solid (1.09 g, 89%). 1H NMR (300 MHz, DMSO-d6) δ 7.69 (d, J=9.0 Hz, 1H), 7.3-7.5(m, 5H), 7.06-7.2(m, 5H), 6.42(m, 1H), 6.28(d, J=2.4 Hz, 1H), 3.93(m, 1H), 3.08(dd, J=7.0, 16 Hz, 2H), 2.72(dd, J=7.0, 16 Hz, 2H), 2.55(s, 3H). LCMS, >99%, m/z (%): 395 (M+·, 100).

1. customthan evaporated to dryness under reduced pressure
2. customThe residue was dried in vacuo for 1 h
3. filtrationThis was filtered
4. customfiltrate was partially evaporated under reduced pressure
5. customThe precipitate formed
6. filtrationwas filtered off
7. washwashed with H2O, small volume of EtOH, Et2O
8. customdried in vacuo