Reaction Steps
Distilled THF (25 mL) was added to 3-chloro-3-(4-chlorophenyl)-3H-isobenzofuran-1-one (3.2 g, 11.5 mmol), 4-nitrobenzylamine hydrochloride (2.3 g, 12.6 mmol), and triethylamine (4.8 mL, 34.5 mmol). The mixture was stirred at room temperature under nitrogen for 4 h and monitored by TLC. On completion the solvent was removed under vacuum, the residue was taken up in ethyl acetate (30 mL), washed with water (3×20 mL), brine (10 mL) and dried (MgSO4). The solvent was removed under vacuum. Recrystallisation (ethyl acetate) gave 3-(4-Chlorophenyl)-3-hydroxy-2-(4-nitrobenzyl)-2,3-dihydroisoindol-1-one as a light yellow solid (2.95 g, 7.47 mmol, 65%); Rf=0.4 (40:60: EtOAc:petrol). mp 197.1-199.7° C. λmax (CH3OH)/nm 225. IR: 3215, 1676, 1517, 1395, 1341 cm1. 1H NMR: (300 MHz, d6-DMSO) δ 4.35 (d, 1H, J=16.3 Hz, N—CH2), 4.61 (d, 1H, J=16.3 Hz, N—CH2), 7.28 (m, 4H, Ar—H), 7.45 (m, 3H, Ar—H), 7.58 (m, 2H, Ar—H), 7.79 (m, 1H, Ar—H), 8.05 (m, 2H, Ar—H). 13C NMR: (75 MHz, d6-DMSO) δ 42.1, 90.5, 123.1, 123.3, 128.4, 128.7, 129.1, 129.9, 130.3, 133.2, 133.3, 138.9, 146.4, 146.5, 149.4, 167.1. LCMS (ESI+) m/z=307.2, 368.2, 377.1. Anal. Calcd. for C21H15ClN2O4: C, 63.89; H, 3.83; N, 7.10%. Found C, 63.78; H, 3.92; N, 7.12%. HRMS (EI) m/z Calcd. for C21H15ClN2O4: 394.0720. Found 394.0714.
