反应详情

To a solution of 2-(iodomethyl)-5-(trifluoromethyl)-2,3-dihydro-1-benzofuran (2.8 g, 8.5 mmol) in CH3CN (40 ml) was added potassium carbonate (2.36 g, 17.1 mmol, 2 eq) and piperazine (2.94 g, 34.1 mmol, 4 eq) at room temperature. The mixture was heated at reflux for 3 hours, the solids were filtered off, and the filtrate was concentrated under vacuum. The crude material was purified by silica gel chromatography using 1-2.5% methanol in dichloromethane to elute. The product-containing fractions were combined and concentrated under vacuum to afford 1-[[5-(trifluoromethyl)-2,3-dihydro-1-benzofuran-2-yl]methyl]piperazine as light yellow oil (1.25 g, 51%); (ES, m/z): [M+H]+ 287; 1H NMR (300 MHz, CDCl3): δ 7.37 (d, J=9.0 Hz, 2H), 6.83 (d, J=8.4 Hz, 1H), 5.00-5.10 (m, 1H), 3.26-3.35 (m, 1H), 2.96-3.04 (m, 1H), 2.88-2.95 (m, 4H), 2.78-2.80 (m, 1H), 2.54-2.69 (m, 4H).

1. temperatureThe mixture was heated
2. temperatureat reflux for 3 hours
3. filtrationthe solids were filtered off
4. concentrationthe filtrate was concentrated under vacuum
5. customThe crude material was purified by silica gel chromatography
6. washto elute
7. concentrationconcentrated under vacuum