4-Methylphenacyl bromide

White to light yellow crystal powder

General procedure: To a solution of olefin (1mmol) in acetone (3mL) and water (0.1mL), TsNBrGeneral 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: The reaction mixture of In(OTf)General 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: In a Nalgene.(R). bottle, to acetophenone (2 mmol) in dichloromethane (10 mL), potassium nitrate (4 mmol) and chloro/bromotrimethylsilane (8 mmol) were added. The heterogeneous mixture was stirred vigorously at 60 °C (for chlorination) or room temperature (for bromination) until the reaction went to completion (monitored by General procedure: Oxone (1.352 g, 2.2 mmol) was added to the well stirred solution of substrate (2 mmol) and NHGeneral procedure: A solution of acetophenone 1a-e (10 mmol), N-bromosuccinimide (12 mmol) and p-toluenesulphonic acid (15 mmol) in acetonitrile (50 mL) was stirred for 4 h at reflux temperature. After completion, the reaction mass was allowed to reach ambient temperature and the solvent was evaporated. The residue was poured into water and extracted with ethyl acetate. The organic layer was dried over anhydrous MgSOGeneral procedure: N-bromosuccinimide (0.37 mmol) was added to the stirredsolution of acetophenone (2) (0.37 mol, 1 equiv) in acetonitrile(40 mL). The resulting reaction mixture was stirredfor 10–15 min. After that p-TsOH (0.74 mmol, 2 equiv) wasadded to the reaction mixture and refluxed for 4–5 h andmonitored by TLC. After completion of reaction, reactioncontent was brought to room temperature and washed withsaturated solution of sodium bicarbonate and extracted withethyl acetate (3 × 20 mL), organic layer was dried oversodium sulphate and concentrated under reduced pressure.The obtained residues were purified by column chromatographyusing silica 100–200 mesh size by ethyl acetate:hexane (4:96) mixture and pure compound was identified as2-bromo-1-phenyl-ethanone 3a–g.The representative example of oxidative bromination is described as follows: A mixture of 1.2 g acetophenone 1a (10 mmol) and 0.121 g Cu(NO4'-Methylacetophenone (402.6 g, 3 moles) and chloroform (1.6 L) was placed in a 3 L 3-necked flask fitted with a mechanical stirrer, a thermocouple connected to a heater controller, a condenser and a nitrogen sweep. The flask was initially placed in a water bath held at 40° C. Solid 1, 3-N, N-dibromo-5, 5-dimethylhydantoin (145.3 g, -0.5 mole) was added to the stirred solution followed by catalytic concentrated sulfuric acid (2.5 ml_). The temperature rose to 45° C. Once the temperature had decreased to ~40° C, the second portion of 1, 3-N, N-dibromo-5, 5-dimethylhydantoin (145.3 g, -0.5 mole) was added. Again, the temperature rose to 45° C and then slowly cooled back to -40° C whereupon the last portion of 1, 3-N, N-dibromo-5, 5-dimethylhydantoin (145.3 g, -0.5 mole) was added. A heating mantle was placed under the flask and the solution was held at 45° C with stirring until the orange color dissipated. The overall addition reaction time was 2.5-3 hours. The HPLC analysis of the crude bromoketone solution showed 5-6percent unreacted ketone, -2percent dibrominated product and -92percent α-bromo^'-methylacetophenone. The solid, 5, 5-dimethyl-hydantoin, was removed by filtration and washed with chloroform (-200 mL). The chloroform filtrate containing the crude α- bromo-4'-methylacetophenone was placed in an addition funnel for transfer.General procedure: In a dry tube, substituted acetophenone (2 mmol), NBS (2 mmol) and PTSA (0.2 mmol, 10 molpercent) were added. 3-4 ml of anhydrous DCM was added and the tube was then irradiated in ultrasonic both till the completion of reaction (TLC). The reaction mixture was then cooled and extracted with 3 x 10 ml quantities of DCM. Organic layers were separated, dried over anhydrous MgSO2-Bromo-1-p-tolyl-1-ethanone To a solution of 1-p-tolyl-ethanone (0.5 g, 4.16 mmol) in dichloromethane-methanol (50 ml-20 mL) was added tetrabutylammonium tribromide (2.2 g, 4.58 mmol) at room temperature. The mixture was stirred until the orange color faded. The solvent was then distilled under reduced pressure and the resulting precipitate was extracted with ethyl acetate. The organic layer was dried over sodium sulfate and evaporated in vacuo to give a residue which was purified by flash column chromatography to yield the desired product 2-bromo-1-p-tolyl-1-ethanone (0.74 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 NaNOGeneral procedure: A mixture of substituted arylethanones 14a-i (10 mmol), N-bromosuccinimide (1.4 g, 12 mmol) and p-toluenesulphonic acid (2.8 g, 15 mmol) in acetonitrile (50 mL) was stirred at 85 °C for 4 h. After completion of reaction (indicated by TLC), the reaction mass was allowed to reach ambient temperature and evaporated excess of acetonitrile under reduced pressure. The residue so obtained was mixed in water, extracted with ethyl acetate (2 × 50 mL). The organic layer was dried over anhydrous NaGeneral procedure: A modified reaction route: NBS (1.2 equiv.) was added to a solution of appropriately substitutedacetophenones 9a–9l (1.0 equiv.) in CH3CN (15 mL) with p-TSA (0.2 equiv.). The solution washeated at 80 °C for 3-5 h until all the starting materials had been consumed (TLC monitored). Thereaction mass was poured in ice-cold water and extracted with DCM (3 × 20 mL). Anhydrous Na2SO4was added to the combined organic layer, filtered and the excess solvent was removed under reducedpressure. The resultant solid/ liquid obtained were washed with hexane to yield compounds 10a–10i.4, 55.36 g (0.04 mol) of p-methylacetophenone in a 100 ml round bottom flask, Add 40 ml of methanol to make the system uniform.Add a few drops of hydrobromic acid as a catalyst, Slowly add a solution of 2 ml (0.04 mol) of bromine in 20 ml of methanol under vigorous stirring at room temperature to control the drop rate.After the color of bromine disappears, add it again.After about 2 hours, Then continue the reaction at room temperature for 2 h, After the reaction is completed, Pour quickly into about 200 ml of ice water with stirring.A large amount of white flocculent or lumpy solid is produced, suction filtered, the filter cake is washed with water, and naturally dried overnight to obtain 7.8 g of a white solid.Melting point: 53 ° C, The yield was 73percentPreparation 10: 2-Bromo-1- (4-methylphenyl)-1-ethanone To a stirring solution of 20 g (150 mmol) of 4-methylacetophenone in 100 mL of glacial acetic acid was added catalytic amount of HBr (0.5 mL) followed by 21.40g (134 mmol) of bromine dissolved in acetic acid (30 mL) dropwise at 10-15 °C. The reaction mixture was stirred at 25-35 °C for 5 hrs, then poured into water (100 mL). The solid that separated was filtered to give the required product (20 g, 65percent).General procedure: A mixture of arene (0.5 mmol), IA 100 mL round bottom flask was charged with 10 mmol of 4-methylacetophenone and 11 mmol of N-bromosuccinimide (NBS).35mL of ethyl acetate dissolved, Then add 1g of Amberlyst 15 ion exchange resin as catalyst.The reaction was warmed to 40°C and reacted. After TLC tracks the reaction, The reaction solution was filtered to remove Amberlyst 15 ion exchange resin, and the filtrate was spin-dried.Column chromatography (eluent: petroleum ether/ethyl acetate) gave pale yellow crystals in 53percent yield.In a 100 mL round-bottomed flask, 10 mmol of 4-methylacetophenone and 11 mmol of N-bromosuccinimide (NBS) were added.35mL of ethyl acetate dissolved, Then add 1g of Amberlyst 15 ion exchange resin as catalyst.The reaction was warmed to 40°C and reacted. After TLC tracks the reaction, The reaction solution was filtered to remove Amberlyst 15 ion exchange resin, and the filtrate was spin-dried.Column chromatography (eluent: petroleum ether/ethyl acetate) gave pale yellow crystals, Yield 53percent.General procedure: A 5mL round-bottom flask was charged with FeClGeneral procedure: To a solution of the olefin (0.5–1.2mmol) in 10–16mL of acetonitrile-water (1:1) mixture was added NBS (1.05equiv) at rt. The reaction mixture was stirred until all the olefin was consumed, as monitored by TLC analysis. Subsequently, TetMe-IA (10molpercent) and Oxone (1.0equiv) were introduced into the reaction mixture, and the stirring was continued. After completion of the oxidation as judged by TLC analysis, the reaction mixture was washed with saturated NaHCOGeneral procedure: To a stirred solution of alkyne (1 mmol) in ethyl acetate(1 mL), 0.1 mL of acetone:water (1:1) and TsNBr2 (2 mmol) wasadded. After 10 min Na2SO3 (8 mmol) was added and the reaction was stirred at room temperature till completion asmonitored by TLC. The organic layer was extracted with ethylacetate, washed with water, dried with Na2SO4 and concentrated.The crude product was purified by flash chromatographyon silica gel (230-400 mesh) using petroleum ethereethyl acetateas eluent.

Molecular Weight:213.07
XLogP3:2.9
Hydrogen Bond Acceptor Count:1
Rotatable Bond Count:2
Exact Mass:211.98368
Monoisotopic Mass:211.98368
Topological Polar Surface Area:17.1
Heavy Atom Count:11
Complexity:137
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes