反应详情

A solution of tert-butyl 4-[(5-chloro-2,3-dihydro-1-benzofuran-2-yl)carbonyl]piperazine-1-carboxylate (400 mg, 1.09 mmol) in dichloromethane (5 ml) was treated with trifluoroacetic acid (1 ml). The resulting solution was stirred for 2 h at room temperature and then concentrated under vacuum to give a residue. The crude material was dissolved into water (20 ml) and the pH was adjusted to ˜8 using aqueous sodium bicarbonate. The mixture was extracted with ethyl acetate (3×100 ml). The organic layers were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum to afford 1-[(5-chloro-2,3-dihydro-1-benzofuran-2-yl)carbonyl]piperazine as light yellow oil (280 mg, 96%). (ES, m/z): [M+H]+ 267; 1H NMR (300 MHz, CDCl3): δ 7.20 (s, 1H), 7.05-7.11 (m, 1H), 6.70 (d, J=8.4 Hz, 1H), 5.46-5.55 (m, 1H), 3.85-3.95 (m, 3H), 3.53-3.63 (m, 2H), 3.25-3.35 (m, 1H), 2.90-3.05 (m, 4H).

1. concentrationconcentrated under vacuum
2. customto give a residue
3. extractionThe mixture was extracted with ethyl acetate (3×100 ml)
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated under vacuum