Methylparaben → 4-[5-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-pentyloxy]-benzoic acid methyl ester

A mixture of 4-hydroxy-benzoic acid methyl ester (3.01 g, 19.8 mmol), 2-(5-bromo-pentyl)-isoindole-1,3-dione (3.9 g, 13.2 mmol), and K2CO3 (1.82 g, 13.2 mmol) in acetone (150 mL) was heated to reflux for 24 hrs. The reaction mixture was cooled to rt and the solvents were removed in vacuo. The crude was diluted in EtOAc and washed with 1N NaOH and brine. The organic layer was dried over sodium sulfate. The solvents were removed in vacuo. The crude was recrystallized from EtOAc to afford the title compound as a white solid (4 g, 83%). 1H-NMR (CDCl3): δ 7.95–7.98 (m, 2H), 7.83–7.86 (m, 2H), 7.70–7.73 (m, 2H), 6.86–6.89 (m, 2H), 4.00 (t, 2H, J=6.22 Hz), 3.88 (s, 3H), 3.73 (t, 2H, J=7.29 Hz), 1.82–1.89 (m, 2H), 1.73–1.81 (m, 2H), 1.50–1.57 (m, 2H).