3-Nitrophenacyl bromide

beige-orange to yellow-green crystalline powder

2-bromo-1-(3-nitrophenyl)ethanone (2a-1). To a suspension of commercially available 3- nitroacetophenone (4.82 g, 29.19 mmol) in anhydrous diethyl ether (25 mL) was added aluminum chloride (0.16 g, 1.20 mmol). The reaction mixture was then cooled to 0°C before dropwise addition of bromine (1.50 mL, 29.19 mmol). The reaction was stirred for lh at room temperature until complete conversion of the starting material (To a suspension of commercially available 3-nitroacetophenone (4.82 g, 29.19 mmol) in anhydrous diethyl ether (25 mL) was added aluminum chloride (0.16 g, 1.20 mmol). The reaction mixture was then cooled to 0°C before dropwise addition of bromine (1.50 mL, 29.19 mmol). The reaction was stirred for 1h at room temperature until complete conversion of the starting material (1H NMR monitoring) and quenched quickly to avoid di-brominated compound formation. After addition of water (30 mL), the mixture was extracted with diethyl ether (3 x 30 mL) and dried with MgSO4 to afford compound 2 as a yellowish brown solid (5.73 g, 97percent yield). 1H NMR (CDCl3, 200 MHz): δ 4.50 (s, 2H, H1), 7.73 (t, J = 8.0 Hz, 1H and H7), 8.31 (ddd, J = 7.8, 1.7, 1.1 Hz, 1H, H8), 8.43 (ddd, J = 8.2, 2.3, 1.1 Hz, 1H, H6), 8.76 (t, J = 1.9 Hz, 1H, H4). 13C NMR (CDCl3, 200 MHz): δ 30.4, 123.9, 128.2, 130.4, 134.6, 135.2, 148.6, 189.5. MS-ESI (m/z): [M+H]+= 244.9.General procedure: To a mixture of NXS and substrate (1 or 6) in CHSynthesis 53; 2-Bromo-1-(3-nitrophenyl)ethanone/77-Nitroacetophenone (20 g) was dissolved in acetic acid (150 mL) under argon. Pyridinium tribromide (38.7 g) was added at once; the reaction was allowed to stir at room temperature for 1 hour and then quenched with water (250 mL). The product was filtered and air dried to give the title compound (25 g, 84percent).General procedure: In a RBF cooled in ice bath at 0 C, HBr(12 mmol, in 2 ml of water) was taken. To this a solution of NaNO48mmol of m-nitroacetophenone was dissolved in 300mL of glacial acetic acid and warmed to 55°C. 48mmol of bromine was then added drop-to-drop allowing the discoloration of the solution before add next drop. After 30min at 55°C, 101g of crushed ice was added to the reaction and the formed precipitated filtered out, washed with water and recrystallized from ethanol/petroleum ether, rendering the compound 2-brome-1-(m-nitrophenyl)ethan-1-one. Yield: 73percent.A solution of phenyltrimethylammonium tribromide (50.1 g, 133 mmol) in THF (200 mL)was added dropwise to a stirred solution of 1-(3-nitrophenyl)ethanone (20 g, 121 mmol)in THF (200 mL) at room temperature. The reaction mixture was allowed to stir at roomtemperature for lh. The white suspension was filtered and the filter cake was washed withTHF, the filtrate was evaporated in vacuum to give a yellow oil. The residue was then dissolved in EtOAc and was washed with water. The organic layer was dried (MgSO4) and evaporated in vacuum to give a yellow oil that solidified into an yelLow solid. Solid recrystallised from propan-2-ol and final product was isolated as an off-white solid. 2-Bromo-l-(3-nitrophenyl)ethanone (20.5 g, 70 percent yield).(‘H, 600 MHz, 20°C, CDC13) 8: 8, 83 (IH, t, 3 = 2Hz), 8.49 (IH, ddd, I = 1.0, 2.3, 8.2Hz), 8.34 (1H, ddd, I = 1.0, 1.7, 7.8 Hz), 7.75 (1H, t, J = 8.1 Hz), 4.49 (2H, s).(‘3C, 150 MHz, 20°C, CDC13) 8: 189.3, 148.5, 135.1, 134.4, 130.2, 128.1, 123.8, 29.9Melting point (mp): 90-9 1 DC.A solution of phenyltrimethylammonium tribromide (50.1 g, 133 mmol) in THF (200 mL) was added dropwise to a stirred solution of l-(3-nitrophenyl)ethanone (20 g, 121 mmol) in THF (200 mL) at room temperature. The reaction mixture was allowed to stir at room temperature for lh. The white suspension was filtered and the filter cake was washed with THF, the filtrate was evaporated in vacuum to give a yellow oil. The residue was then dissolved in EtOAc and was washed with water. The organic layer was dried (MgS0Into a 500-mL 3-necked round-bottom flask, was placed a solution of l-(3-mtrophenyl)ethanone (50 g, 303 03 mmol, 1 00 eqmv) in acetic acid (300 mL), BrGeneral procedure: The α-bromination reaction was carried out using acetophenone (1200 mg, 10 mmol), N-bromosuccinimide (2136 mg, 12 mmol), 10percent (w/w) silica gel (120mg) in 10 mL of methanol at reflux conditions until the disappearance of the substrate. (Note: 2136mg of N-bromosuccinimide was added portion wise i.e. 356 mg for each time in six portions). The progress of the reaction was monitored by TLC. The reaction mass was filtered after the completion of the reaction as per TLC and the catalyst was collected for reuse. The filtrate was concentrated under vacuum. Double distilled water was added to the reaction mixture and quenched with aqueous sodium thiosulfate and the product extracted with dichloromethane (Caution: Severe burning sensation of eyes was observed during the work-up process). The layers were separated and the organic layer was collected and washed thrice with distilled water (3×50mL). The collected organic layer was dried over anhydrous NaGeneral procedure: A mixture of haloalkyne (0.5 mmol), AgF (5molpercent) and water (1 equiv.) in TFA (1 mL) was stirred at 40°C for 6h, after which TFA was distilled out for reuse. The residue was separated by column chromatography to give the pure sample.General procedure: Oxone (1.352 g, 2.2 mmol) was added to the well stirred solution of substrate (2 mmol) and NHGeneral procedure: Oxone (1.352 g, 2.2 mmol) was added to the well stirred solution of substrate (2 mmol) and NH

Used in pesticide, pharmaceutical and chemical intermediates

Molecular Weight:244.04
XLogP3:2.2
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:2
Exact Mass:242.95311
Monoisotopic Mass:242.95311
Topological Polar Surface Area:62.9
Heavy Atom Count:13
Complexity:214
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes