Phenylsuccinic Anhydride → 1-(2,2,4,6,7-Pentamethyl-3-(4-methylphenyl)-2,3-dihydro-1-benzofuran-5-yl)-3-phenylpyrrolidine-2,5-dione

Participants

Reaction Conditions

Reaction Steps

A solution of 2,2,4,6,7-pentamethyl-3-(4-methylphenyl)-2,3-dihydro-1-benzofuran-5-amine (2.95 g, 10 mmol) and phenylsuccinic anhydride (1.94 g, 11 mmol) in toluene was refluxed for 6 hours. The reaction mixture was concentrated under reduced pressure. The residue was diluted with water and extracted with ethyl acetate. The extract was washed with saturated aqueous sodium chloride, dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure. A mixture of the residue and sodium acetate (0.86 g, 10.5 mmol) in acetic anhydride (60 ml) was stirred at 90° C. for 1 hour. The reaction mixture was concentrated under reduced pressure. The residue was diluted with water and extracted with ethyl acetate. The extract was washed with saturated aqueous sodium chloride, dried over anhydrous sodium sulfate, and removed under reduced pressure. The residue was purified with silica gel column chromatography (hexane/ethyl acetate−4/1) to obtain 2.27 g (yield 50%) of the title compound. mp. 130–131° C. low polarity product, 1H-NMR (CDCl3) δ: 1.00 (3H, s)=1.52 (3H, s), 1.64 (3H, s), 2.02 (3H, s), 2.16 (3H, s), 2.30 (3H, s), 3.00 (1H, dd, J=4.7, 18.5 Hz), 3.36 (1H, dd, J=9.5, 18.5 Hz), 4.15–4.25 (2H, m), 6.85 (2H, br), 7.06 (2H, brd, J=6.6 Hz), 7.30–7.47 (5H, m).

Provenance & Evidence