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 h, then solids were filtered out 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 h
3. filtrationsolids were filtered out
4. concentrationthe filtrate was concentrated under vacuum
5. customThe crude material was purified by silica gel chromatography
6. washto elute
7. concentrationconcentrated under vacuum