Reaktion #443812

Reaktionsgleichung

5-bromo-o-anisaldehyde

ethylene glycol

ethylene glycol

→

2-(5-bromo-2-methoxyphenyl)-1,3-dioxolane

Ausbeute 126.5%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturat reflux for 21 hr
2. 2
   Temperaturheated
3. 3
   Temperaturat reflux for 6 hr
4. 4
   WaschenThe resulting solution was washed with sat. NaHCO3, water and brine
5. 5
   Trocknendried over MgSO4
6. 6
   Einengenconcentrated in vacuo

Vorschrift

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.

Quelle