1-bromo-3-(bromomethyl)-5-methylbenzene

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 3,5-dimethylbromobenzene (80.25 g, 0.43M), NBS (77 g, 0.43M), and benzoyl peroxide (5.2 g, 0.021M) in carbon tetrachloride (400 ml) was refluxed for 3 hr. under a light of 500 W tungsten light. After cooling to room temperature, the mixture was filtered and the filtrate was evaporated in vacuo to give a white solid, which was purified by silica gel column chromatography (eluent, hexane) to afford 82 g (72%) of a white solid. m.p. 46-47° C.; 1H NMR (200 MHz, CDCl3) δ 2.32 (3H, s), 4.38 (2H, s), 7.12 (1H, s), 7.25 (1H, s), 7.33 (1H, s). was refluxed for 3 hr the mixture was filtered the filtrate was evaporated in vacuo to give a white solid, which was purified by silica gel column chromatography (eluent, hexane)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The mixture of 3,5-dimethylbromobenzene (80.25 g, 0.43M), NBS (77 g, 0.43M), and benzoyl peroxide (5.2 g, 0.021M) in carbon tetrachloride (400 ml) was refluxed for 3 hr. under a light of 500 W tungsten light. After cooling to room temperature, the mixture was filtered and the filtrate was evaporated in vacuo to give a white solid, which was purified by silica gel column chromatography (eluent, hexane) to afford 82 g (72%) of a white solid; m.p. 46-47° C.; 1H NMR (200 MHz, CDCl3) δδ 2.32 (3H, s), 4.38 (2H, s), 7.12 (1H, s), 7.25 (1H, s), 7.33 (1H, s). was refluxed for 3 hr the mixture was filtered the filtrate was evaporated in vacuo to give a white solid, which was purified by silica gel column chromatography (eluent, hexane)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 3-bromo-5-methylbenzyl bromide (Step A above) (5.49 g, 20 mmole) in glacial acetic acid (9.0 mL) and H2O` (9 mL) was added hexamethylenetetramine (4.50 g, 32 mmole) and the reaction was stirred at reflux for 2 hours. Concentrated HCl (7.0 mL) was added and the mixture was refluxed an additional 15 minutes. After cooling to room temperature, the reaction mixture was diluted with H2O (75 mL) and extracted with ether (150 mL). The ether layer was washed with H2O (3×25 mL), 10% NaHCO3 (2×50 mL) and dried over MgSO4. The ether was removed under vacuum and the residue was chromatographed on silica gel eluting with hexane and 10% Et2O/hexane to yield 3-bromo-5-methylbenzaldehyde (2.80 g) as a light yellow oil which solidified upon standing. MS and NMR were consistent with the desired structure. at reflux for 2 hours the mixture was refluxed an additional 15 minutes extracted with ether (150 mL) The ether layer was washed with H2O (3×25 mL), 10% NaHCO3 (2×50 mL) dried over MgSO4 The ether was removed under vacuum the residue was chromatographed on silica gel eluting with hexane and 10% Et2O/hexane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 5-bromo-m-xylene (24.03 g, 0.13 mole) in benzene (125 mL) was added benzoylperoxide (3.04 g, 0.013 mole). The reaction mixture was heated to reflux in a 250 mL round bottom flask. N-bromosuccinimide (18.15 g, 0.10 mole) was added in portions over 15 minutes. After 2 hours, heating was discontinued and the reaction mixture was allowed to cool to room temperature. Precipitated solids were removed by filtration and the filtrate was concentrated. The residue was taken up in hexane and additional solids were removed by filtration. The filtrate was passed through a small pad of silica gel and the filtrate was concentrated. The resultant yellow oil was titurated with MeOH over ice to give 3-bromo-5-methylbenzyl bromide (7.34 g) as a white solid. MS and NMR were consistent with the desired structure. The reaction mixture was heated to reflux in a 250 mL round bottom flask heating Precipitated solids were removed by filtration the filtrate was concentrated additional solids were removed by filtration the filtrate was concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 1-bromo-3-(bromomethyl)-5-methylbenzene (40.0 g, 151 mmol), 1,4-dioxane (150 mL), water (150 mL) and calcium carbonate (37.9 g, 379 mmol) was heated for 16 h at reflux. The mixture was filtered and the filtrate was concentrated in vacuum, then diluted with CH2Cl2 (150 mL). The organic layer was washed with HCl (2N, 50 mL) and a solution of saturated sodium bicarbonate (50 mL), dried over (Na2SO4) and concentrated in vacuum to give 25.0 g of crude product (3-bromo-5-methylphenyl)methanol. was heated for 16 h at reflux The mixture was filtered the filtrate was concentrated in vacuum diluted with CH2Cl2 (150 mL) The organic layer was washed with HCl (2N, 50 mL) a solution of saturated sodium bicarbonate (50 mL), dried over (Na2SO4) concentrated in vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 1-bromo-3,5-dimethylbenzene (25.0 g, 135 mmol), NBS (24.0 g, 135 mmol) and BPO (1.30 g) in CCl4 (250 mL) was refluxed for 6 h. After cooling to room temperature, the mixture was filtered, and the filtrate was washed successively with saturated sodium bicarbonate (100 mL), water (2×50 mL) and brine (2×50 mL). The combined organic phases were dried (Na2SO4) and concentrated in vacuum to give 40.0 g of crude product 1-bromo-3-(bromomethyl)-5-methylbenzene. was refluxed for 6 h the mixture was filtered the filtrate was washed successively with saturated sodium bicarbonate (100 mL), water (2×50 mL) and brine (2×50 mL) The combined organic phases were dried (Na2SO4) concentrated in vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 1-bromo-3-(bromomethyl)-5-methylbenzene (34.0 g, 128.8 mmol) in DMF (200 mL), was added potassium phthalide (28.9 g, 154.6 mmol, and the mixture was stirred under reflux for 2 h. The reaction was allowed to cool to room temperature. After the solvent was remove under reduced pressure, the residue was dissolved in CH2Cl2 (300 mL), and washed with water (50 mL×3). The organic layer was dried over anhydrous sodium sulfate. Evaporation of the solvent gave a white solid. The solid was recrystallized from toluene and EtOH to give the product, 2-[(3-bromo-5-methylphenyl)methyl]-1H-isoindole-1,3(2H)-dione (28.5 g, 67%). 1H NMR (400 MHz, CDCl3) δ 7.87-7.72 (m, 4H), 7.36 (s, 1H), 7.23 (s, 1H), 7.15 (s, 1H), 4.77 (s, 2H), 2.30 (s, 3H). under reflux for 2 h After the solvent was remove under reduced pressure the residue was dissolved in CH2Cl2 (300 mL) washed with water (50 mL×3) The organic layer was dried over anhydrous sodium sulfate Evaporation of the solvent gave a white solid The solid was recrystallized from toluene and EtOH

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 1-bromo-3,5-dimethylbenzene (25.0 g, 135.0 mmol) in CCl4 (150 mL), was added 1,3-dibromo-5,5-dimethylimidazolidine-2,4-dione (14.5 g, 54.0 mmol) and dibenzoyl peroxide (BPO) (0.2 g) and the mixture was refluxed for 7 h. After the reaction mixture was cooled to room temperature, the precipitate was filtered out using Celite, and then the solid was rinsed two times with pentane (50 mL). The combined filtrates were washed with water (50 mL), followed by saturated sodium bicarbonate (50 mL) and sodium thiosulfate (50 mL×2). The organic layer was dried over anhydrous sodium sulfate. Evaporation of the solvent afforded the compound 1-bromo-3-(bromomethyl)-5-methylbenzene (35.6 g, 99%). the mixture was refluxed for 7 h the precipitate was filtered out the solid was rinsed two times with pentane (50 mL) The combined filtrates were washed with water (50 mL) The organic layer was dried over anhydrous sodium sulfate Evaporation of the solvent