Reaktion #10712

Reaktionsgleichung

Catechol

Diethyl dibromomalonate

potassium carbonate

→

benzo[1,3]dioxole-2,2-dicarboxylic acid diethyl ester

Ausbeute 73.2%

Lösungsmittel

acetone

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solvent was removed under reduced pressure, and water
2. 2
   workup.ADDITIONwas added to the residue
3. 3
   ExtraktionThe residue was extracted with dichloromethane
4. 4
   Waschenthe organic phase was washed with brine
5. 5
   Trocknendried over magnesium sulfate
6. 6
   Sonstigeevaporated

Vorschrift

Ex-1A: Catechol (2.2 g, 20 mmol) was dissolved in acetone. Diethyl dibromomalonate (7.0 g, 22 mmol) and potassium carbonate (2.76 g) were added, and the mixture was stirred at room temperature overnight. The solvent was removed under reduced pressure, and water was added to the residue. The residue was extracted with dichloromethane, and the organic phase was washed with brine, dried over magnesium sulfate and evaporated. Chromatography (hexanes/ethyl acetate, 4:1) gave 3.9 g of benzo[1,3]dioxole-2,2-dicarboxylic acid diethyl ester. 1H-NMR (CDCl3) δ 6.90–6.97 (m, 4H), 4.37 (q, J=7 Hz, 4H), 1.32 (t, J=7 Hz, 6H).

Quelle