1,4-Dioxane → 5-(3-Chlorophenyl)indoline-2,3-dione

Participants

Reaction Steps

A solution of 5-(3-Chloro-phenyl)-1,3-dihydro-indol-2-one (10.0 g, 41 mmol) in dioxane (200 cm3) and SeO2 (22.8 g, 205 mmol) was brought to reflux for 2 h then cooled to RT and concentrated onto Florisil. The Florisil was washed (acetone:CHCl3 1:9) and the combined organic extracts were evaporated. The residue was purified by column chromatography (SiO2, acetone:CHCl3 1:8) to afford the subtitled compound (8 g, 31 mmol, 76%) as a tan solid: m.p. 256–258° C., 1H NMR (THF-d8) δ 6.96 (d, J=8.8 Hz, 1H), 7.33 (d, J=8.1 Hz, 1H), 7.4 (dd, J=7.7, 7.7 Hz, 1H), 7.56 (d, J=7.7 Hz, 1H), 7.68 (dd, J=1.84, 1.84 Hz, 1H), 7.83–7.86 (m, 2H), 10.05 (br s, 1H); 13C NMR (DMSO-d6) δ 113.30 (d), 119.08 (s), 123.44, 125.57, 126.65, 127.92, 131.41 (d), 133.88, 134.47 (s), 137.25 (d), 141.51, 150.99, 160.15, 184.83 (s); MS (EI) m/z 256 (M−H)+; Anal. (C14H8ClNO2-0.1 H2O) C, H, N.

Provenance & Evidence