反应详情

A solution of 5-bromo-o-anisaldehyde (49.7 g, 231 mmol), ethylene glycol (17.2 g, 277 mmol) and p-toluene sulfonic acid (4.3 g, 23 mmol) in dry toluene (400 ml) was heated at reflux for 21 hr. And then ethylene glycol (4.3 g, 70 mmol) was added to the reaction mixture and heated at reflux for 6 hr. The resulting solution was washed with sat. NaHCO3, water and brine, dried over MgSO4 and concentrated in vacuo to give crude 2-(5-bromo-2-methoxyphenyl)-1,3-dioxolane (75.7 g) as a dark red oil. The residue was added NaHCO3 and then distilled to give 2-(5-bromo-2-methoxyphenyl)-1,3-dioxolane (52.8 g, 88.3%) as a colorless oil.

1. temperatureat reflux for 21 hr
2. temperatureheated
3. temperatureat reflux for 6 hr
4. washThe resulting solution was washed with sat. NaHCO3, water and brine
5. dry with materialdried over MgSO4
6. concentrationconcentrated in vacuo