Bromine → 7-Bromo-5-chloro-2,3-dihydrobenzofuran

Beteiligte Stoffe

Reaktionsschritte

To a stirred solution of (33) (1.84 g, 11.93 mmol) in acetic acid (10 ml) at 0° C., was slowly added a solution of bromine (1.24 ml, 24 mmol) in acetic acid (5 ml). The reaction mixture was stirred at room temperature for 4.5 h. A 10% sodium thiosulphate solution (70 ml) was added and the mixture stirred for 10 min. The bulk of the solvent was evaporated in vacuo. The resulting oil was dissolved in ether (50 ml), washed with water (20 ml), saturated NaHCO2 (2×15 ml), brine (1×15 ml), dried Na2SO4 and evaporated in vacuo to give 2.55 g (92%) of (34) as a oil.

Herkunft & Nachweise