1-(diphenylmethyl)-1H-indole-2,3-dione → 1-(diphenylmethyl)-3-hydroxy-3-(7-hydroxy-3,4-dihydro-2H-chromen-6-yl)-1,3-dihydro-2H-indol-2-one

Participants

Reaction Conditions

Reaction Steps

To a cooled (0° C.) solution of chroman-7-ol (Cube, R. V., et al., Bioorg. Med. Chem. Lett. (2005), 15(9):2389-93) (0.55 g, 3.66 mmol) in tetrahydrofuran (11 mL) under nitrogen was added isopropylmagnesium chloride (2.4 mL, 2 M in tetrahydrofuran, 4.8 mmol). The resulting solution was stirred at 0° C. for 30 min. A suspension of 1-(diphenylmethyl)indoline-2,3-dione (1.16 g, 3.70 mmol) in dichloromethane (4 mL) was added. The reaction was stirred at 0° C. for 10 min, then warmed to ambient temperature and stirred for 15.5 h. The reaction was diluted with saturated ammonium chloride solution (10 mL) and the organic solvents were removed under reduced pressure. The residual mixture was diluted with water (50 mL) and extracted with ethyl acetate (3×25 mL). The combined organic solution was washed with brine (50 mL), dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by flash column chromatography with hexanes/ethyl acetate (7:3) to afford 1-(diphenylmethyl)-3-hydroxy-3-(7-hydroxy-3,4-dihydro-2H-chromen-6-yl)-1,3-dihydro-2H-indol-2-one (1.37 g, 81%) as a light yellow solid: mp 204-206° C. (diethyl ether/hexanes); 1H NMR (300 MHz, CDCl3) δ8.90 (s, 1H), 7.49 (dd, J=5.6, 3.2 Hz, 1H), 7.38-7.23 (m, 10H), 7.12-7.06 (m, 2H), 6.95 (s, 1H), 6.52-6.47 (m, 3H), 4.23 (s, 1H), 4.121 (dd, J=5.7, 4.5 Hz, 2H), 2.53 (t, J=6.3 Hz, 2H), 1.95-1.87 (m, 2H); MS (ES+) m/z 486.1 (M+23).

Provenance & Evidence