4'-Chloro-3'-nitroacetophenone → 2-Bromo-1-(4-chloro-3-nitrophenyl)ethan-1-one

Participants

Reaction Steps

To a flask equipped with a magnetic stir bar and under an atmosphere of N2 was added 4′-chloro-3′-nitroacetophenone (10.0 g, 50.1 mmol) and THF (100 mL). To this stirring mixture was added portion-wise phenyltrimethylammonium tribromide (19.78 g, 52.6 mmol) over a 15 minutes time period. The resultant mixture was then stirred with monitoring every hour via LCMS. After 3 hr the mixture was then filtered and resulting solids washed with EtOAc. The organic solution was then concentrated, H2O and 10% aq. NaHCO3 added and washed with EtOAc (2×300 mL). The combined organic layers were then washed with Brine, dried (MgSO4), filtered and concentrated. The residue material was then subjected to purification via crystallization (dissolved material in 100 mL EtOAc and slowly added hexanes until cloudy—let stand for a few hours) to yield 9.81 g (70%) of 2-bromo-1-(4-chloro-3-nitrophenyl)ethanone as an off white colored solid product. 1H NMR (500 MHz, DMSO-D6) δ ppm 5.00 (s, 2H) 7.98 (d, J=8.54 Hz, 1H) 8.24 (dd, J=8.54, 2.14 Hz, 1H) 8.61 (d, J=1.98 Hz, 1H).

Provenance & Evidence