(a) A reaction mixture of p-bromobenzyl bromide (4.00 g, 16.004 mmol) and phthalimide potassium salt (3.26 g, 17.61 mmol) in N,N-dimethylformamide (DMF, 10 mL) was subjected to an oil bath at 100 °C, CaCl2 was added as a desiccant, and the reaction was stirred for 6 hours. After completion of the reaction, the reaction was cooled to room temperature, the reaction was quenched by the addition of deionized water (100 mL), and the reaction mixture was extracted with ethyl acetate (AcOEt, 100 mL x 3). The organic phases were combined, washed sequentially with deionized water (100 mL×1) and saturated saline (100 mL×1), dried over anhydrous sodium sulfate (Na2SO4), filtered, and concentrated under reduced pressure to afford 2-(4-bromobenzyl)isoindoline-1,3-dione (5.28 g, quantitative yield) as a colorless solid. Colorless cottony crystals were obtained by recrystallization from hexane/ethyl acetate mixed solvent. Melting point 126-129 °C. 1H NMR (300 MHz, CDCl3) δ 4.80 (2H, s, CH2), 7.32 (2H, d, J = 7.8 Hz, ArH), 7.44 (2H, d, J = 8.1 Hz, ArH), 7.71-7.73 (2H, m, ArH), 7.84-7.85 (2H, m, ArH ).
