Reaktion #51203

Reaktionsgleichung

EtOAc

2,3-Dihydrobenzo[b]furan

SnCl4

Dichloromethyl methyl ether

→

title product

Ausbeute 0.6%

2,3-Dihydrobenzo[b]furan-7-carboxaldehyde

Ausbeute 0.6%

Lösungsmittel

pentane

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto produce a pale yellow solution
2. 2
   workup.STIRRINGthe solution stirred for 30 min
3. 3
   Sonstigeafter which time the cooling bath was removed
4. 4
   workup.ADDITIONthe reaction poured onto ice-water (1000 ml)
5. 5
   SonstigeThe organic layer was separated
6. 6
   Waschenwashed with water (2×100 ml), 2N HCl (100 ml) and brine (50 ml)
7. 7
   workup.ADDITIONcharcoal (30 g) and Na2SO4 were added to the solution
8. 8
   FiltrationFiltration
9. 9
   Sonstigethrough Celite and evaporation
10. 10
    Sonstigegave a black oil, which

Vorschrift

2,3-Dihydrobenzo[b]furan (Maybridge Chemicals) (25 g, 0.21 mole) was taken up in DCM (500 ml) and stirred under nitrogen at 0° C. SnCl4 (36.5 ml, 0.3 mole) was added in one portion to produce a pale yellow solution. Dichloromethyl methyl ether (18.8 ml, 0.21 mole) was then added and the solution stirred for 30 min, after which time the cooling bath was removed and the reaction poured onto ice-water (1000 ml). The organic layer was separated, washed with water (2×100 ml), 2N HCl (100 ml) and brine (50 ml), and then charcoal (30 g) and Na2SO4 were added to the solution. Filtration through Celite and evaporation gave a black oil, which was subjected to flash chromatography using 7-10% EtOAc in pentane to give the title product (190 mg, 0.01%); 1HNMR (400 MHz, CDCl3) δ: 3.24 (t, 2H), 4.75 (t, 2H), 6.93 (t, 1H), 7.40 (d, 1H), 7.59 (d, 1H), 10.2 (s, 1H); LRMS: (M+H) 149, TS+. Anal. Found: C, 72.98; H, 5.46%. C9H8O2 requires C, 72.96; H, 5.44%.

Quelle