Reaktion #46197

Reaktionsgleichung

methyl 3,4-dihydroxy-5-methoxybenzoate

K2CO3

→

methyl 7-methoxybenzo[d][1,3]dioxole-5-carboxylate

Ausbeute 80.0%

Lösungsmittel

acetone

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe resulting mixture was heated
2. 2
   Temperaturat reflux for 4 h
3. 3
   Filtrationsolid K2CO3 was filtered off
4. 4
   EinengenThe filtrate was concentrated under reduced pressure
5. 5
   workup.DISSOLUTIONthe residue was dissolved in EtOAc (100 mL)
6. 6
   WaschenThe organic layer was washed with water
7. 7
   Trocknendried over anhydrous Na2SO4
8. 8
   Sonstigeevaporated under reduced pressure
9. 9
   Sonstigeto give the crude product, which
10. 10
    Sonstigewas purified by column chromatography on silica gel (Petroleum Ether/Ethyl Acetate=10:1)

Vorschrift

To a solution of methyl 3,4-dihydroxy-5-methoxybenzoate (15.3 g, 0.078 mol) in acetone (500 mL) was added CH2BrCl (34.4 g, 0.27 mol) and K2CO3 (75 g, 0.54 mol) at 80° C. The resulting mixture was heated at reflux for 4 h. The mixture was cooled to room temperature and solid K2CO3 was filtered off. The filtrate was concentrated under reduced pressure, and the residue was dissolved in EtOAc (100 mL). The organic layer was washed with water, dried over anhydrous Na2SO4, and evaporated under reduced pressure to give the crude product, which was purified by column chromatography on silica gel (Petroleum Ether/Ethyl Acetate=10:1) to afford methyl 7-methoxybenzo[d][1,3]dioxole-5-carboxylate (12.6 g, 80%). 1H NMR (400 MHz, CDCl3) δ 7.32 (s, 1H), 7.21 (s, 1H), 6.05 (s, 2H), 3.93 (s, 3H), 3.88 (s, 3H).

Quelle