Trifluoroacetic acid → 1-(diphenylmethyl)-3-(2-hydroxy-4-methoxyphenyl)-1,3-dihydro-2H-indol-2-one

Participants

Reaction Steps

To a solution of 1-(diphenylmethyl)-3-hydroxy-3-(2-hydroxy-4-methoxyphenyl)-1,3-dihydro-2H-indol-2-one (27.9 g, 63.8 mmol) in dichloromethane (200 mL) were added trifluoroacetic acid (2 mL) and triethylsilane (1.5 mL) at ambient temperature. The reaction mixture was refluxed for 15 h. The mixture was concentrated in vacuo to dryness. The residue was purified by flash chromatograph using 25% ethyl acetate in hexane to afford 1-(diphenylmethyl)-3-(2-hydroxy-4-methoxyphenyl)-1,3-dihydro-2H-indol-2-one (7.40 g, 27%) as a colorless solid: 1H NMR (300 MHz, CDCl3) δ 7.40-7.18 (m, 11H), 7.13-7.06 (m, 2H), 6.97 (s, 1H), 6.83 (d, J=8.4 Hz, 1H), 6.67-6.64 (m, 1H), 6.57-6.52 (m, 1H), 6.41 (dd, J=8.4, 2.4 Hz, 1H), 5.11 (s, 1H), 3.77 (s, 3H).

Provenance & Evidence