反应详情

A mixture of (4-(2,2-Diethoxyethoxy)phenyl)(phenyl)sulfane (2.7 g, 8.5 mmol) and polyphosphoric acid (2.7 g, 27 mmol) in benzene (70 mL) was stirred at reflux for 2 h. The reaction mixture was cooled to room temperature, decanted from the PPA and filtered through a plug of silica gel, which was washed with hexanes. The filtrate and the wash were combined and concentrated under reduced pressure to yield 1.7 g (89%) of benzofuran: 1H NMR (400 MHz, CDCl3) δ 7.74 (d, 1H), 7.64 (dd, 1H), 7.49-7.39 (m, 2H), 7.29-7.16 (m, 5H), 6.74 (dd, 1H).

1. temperatureat reflux for 2 h
2. customdecanted from the PPA
3. filtrationfiltered through a plug of silica gel, which
4. washwas washed with hexanes
5. concentrationconcentrated under reduced pressure