反应详情

Triphenylphosphane dibromide (5.52 g, 14.4 mmoles) was suspended in abs. acetonitrile (15 ml) under argon, the suspension was brought to 19° C. in a water-bath and 2-(benzofuran-3-yl)ethanol (2.11 g, 13.1 mmoles) in abs. acetonitrile (7 ml) was added in the course of 15 min. During the addition the temperature of the reaction mixture was kept between 19 and 21° C. The mixture was then left to stand for 12 hours without further cooling. The reaction mixture was filtered and the filtrate obtained was concentrated. The residue obtained was taken up in cyclohexane (20 ml), and the mixture was filtered over a silica gel layer (15 g) about 3 cm thick. The silica gel was washed with cyclohexane (5×20 ml) and the filtrate obtained was concentrated. 2.47 g 3-(2-bromoethyl)benzofuran were obtained as a yellowish oil.

1. additionDuring the addition the temperature of the reaction mixture
2. customwas kept between 19 and 21° C
3. waitThe mixture was then left
4. filtrationThe reaction mixture was filtered
5. customthe filtrate obtained
6. concentrationwas concentrated
7. customThe residue obtained
8. filtrationthe mixture was filtered over a silica gel layer (15 g) about 3 cm thick
9. washThe silica gel was washed with cyclohexane (5×20 ml)
10. customthe filtrate obtained
11. concentrationwas concentrated