2-(4-Bromobenzyl)isoindoline-1,3-dione

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: To a suspension of 10 g (44.94 mmol) of 4-bromobenzylamine hydrochloride in 200 ml of chloroform was added 12.5 ml (89.62 mmol) of triethylamine, followed by the addition of 8.99 g (60.67 mmol) of phthalic anhydride. The mixture was stirred at room temperature for 10 minutes to give a homogeneous solution, which was then heated at 75° C. for three hours. The reaction mixture was then evaporated to remove the chloroform and the residue was suspended in 400 ml of toluene followed by adding 700 mg of p-toluenesulfonic acid monohydrate. The resulting mixture was briefly refluxed at 140° C., and additional 3 ml of triethylamine was added to form a homogeneous solution. The solution was refluxed at 140° C. for 2 hours; and the water formed was collected through a Dean-Stark trap apparatus. The solution was then cooled to room temperature, washed with 3% sodium hydroxide (2×200 ml), water (1×200 ml), brine (1×200 ml), and dried over sodium sulfate. Removal of the solvent under reduced pressure gave 12.07 g (85% yield) of 4-phthalimidomethyl bromobenzene as a white solid. Rf: 0.6 (silica gel, ethyl acetate:hexane=1:2). 1H NMR (CDCl3): δ ppm 4.79 (2H, s), 7.31, 7.44 (2H each, AA'BB'), 7.73, 7.84 (2H each, m). to give a homogeneous solution, which was then heated at 75° C. for three hours The reaction mixture was then evaporated to remove the chloroform by adding 700 mg of p-toluenesulfonic acid monohydrate The resulting mixture was briefly refluxed at 140° C. additional 3 ml of triethylamine was added to form a homogeneous solution The solution was refluxed at 140° C. for 2 hours was collected through a Dean-Stark trap apparatus The solution was then cooled to room temperature washed with 3% sodium hydroxide (2×200 ml), water (1×200 ml), brine (1×200 ml) dried over sodium sulfate Removal of the solvent under reduced pressure