Bromine → 1,5-Dibromo-2,4-difluorobenzene

Participants

Reaction Steps

To a solution of 1-bromo-2,4-difluorobenzene (19.3 mL, 171 mmol) in CH2Cl2 (100 mL) was added iron (3.15 g, 56 mmol). To this stirred suspension was added a solution of bromine (11 mL, 214 mmol) in CH2Cl2 (25 mL) drop wise over 30 min. The resulting mixture was stirred at rt overnight. The reaction mixture was slowly poured into saturated aqueous Na2S2O3 (200 mL), and the resulting mixture was stirred at rt for 30 min. This was extracted with CH2Cl2 (3×80 mL). The combined extracts were washed with brine, dried over MgSO4, filtered and concentrated in vacuo to give 1,5-dibromo-2,4-difluorobenzene (40 g, 86% yield) as a brown oil. 1H NMR (500 MHz, CHLOROFORM-d) δ 7.79 (t, J=7.0 Hz, 1H), 7.00 (t, J=8.2 Hz, 1H).

Provenance & Evidence