Reaktion #52303

Reaktionsgleichung

5-(2,2-dibromo-vinyl)-benzo[1,3]dioxole

n-butyllithium

→

title compound

Ausbeute 95.0%

5-Ethynyl-benzo[1,3]dioxole

Ausbeute 95.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter the addition
2. 2
   Sonstigequenched with saturated NH4Cl
3. 3
   SonstigeTHF was removed
4. 4
   ExtraktionThe aqueous was extracted with ethyl acetate
5. 5
   WaschenThe organic layer was washed with water, brine
6. 6
   Trocknendried over Na2SO4
7. 7
   Einengenconcentrated
8. 8
   Sonstigeflash chromatographed on silica gel
9. 9
   Wascheneluting with DCM/hexane (5 to 10%)

Vorschrift

To a solution of 5-(2,2-dibromo-vinyl)-benzo[1,3]dioxole (1.47 g, 5.0 mmol) in THF (10 mL) at −78° C. was added 2.0 M solution of n-butyllithium (5.5 mL, in cyclohexane) over 5 minutes period. After the addition completed, the reaction was stirred for 1 h, and then quenched with saturated NH4Cl. The mixture was allowed to warm up to room temperature. THF was removed. The aqueous was extracted with ethyl acetate. The organic layer was washed with water, brine, dried over Na2SO4, concentrated, and flash chromatographed on silica gel, eluting with DCM/hexane (5 to 10%) to give the title compound (0.64 g, 95% yield) as an orange oil. 1H NMR (CDCl3) δ 7.02 (dd, 1H, J=1.6, 8.1 Hz), 6.93 (d, 1H, J=1.6 Hz), 6.75 (d, 1H, J=8.0 Hz), 5.98 (s, 2H), 2.97 (s, 1H).

Quelle