5-(2,2-Dibromo-vinyl)-benzo[1,3]dioxole → 5-Ethynylbenzo-1,3-dioxole

Participants

Reaction Steps

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).

Provenance & Evidence