Trifluoroacetic acid → 3-(6-hydroxy-3-methyl-1,2-benzisoxazol-5-yl)-1-(4-methoxybenzyl)-1,3-dihydro-2H-indol-2-one

Participants

Reaction Steps

To a stirred solution of 3-hydroxy-3-(6-hydroxy-3-methyl-1,2-benzisoxazol-5-yl)-1-(4-methoxybenzyl)-1,3-dihydro-2H-indol-2-one (3.70 g; 8.9 mmol) and triethylsilane (8.4 mL, 52.6 mmol) in dichloromethane (50 mL) was added trifluoroacetic acid (7.0 mL, 90.8 mmol). The reaction mixture was stirred at ambient temperature for 57 h, concentrated in vacuo to dryness. The residue was washed with diethyl ether-hexanes (1:2) to afford 3-(6-hydroxy-3-methyl-1,2-benzisoxazol-5-yl)-1-(4-methoxybenzyl)-1,3-dihydro-2H-indol-2-one (3.34 g, 93%): mp 195-197° C. (diethyl ether/hexanes); 1H NMR (300 MHz, CDCl3) 7.37 (d, J=9.0 Hz, 2H), 7.19-7.14 (m, 1H), 7.03-6.81 (m, 6H), 6.42 (d, J=9.0 Hz, 1H), 5.46 (s, 1H), 5.04 (Aq, 2H), 3.74 (s, 3H), 2.43 (s, 3H); MS (ES+) m/z 401.0 (M+1).

Provenance & Evidence