Cesium carbonate → 1'-(diphenylmethyl)-6-methoxy-5-methylspiro[1-benzofuran-3,3'-indol]-2'(1'H)-one

Participants

Reaction Steps

To a mixture of 1-(diphenylmethyl)-3-(2-hydroxy-4-methoxy-5-methylphenyl)-1,3-dihydro-2H-indol-2-one (10.6 g, 24.4 mmol) and cesium carbonate (23.8 g, 73.1 mmol) in tetrahydrofuran (100 mL) was added chloroiodomethane (6.35 g, 36.6 mmol) under nitrogen. The mixture was stirred at ambient temperature for 3 h, then filtered through a pad of silica and rinsed with tetrahydrofuran (500 mL). The filtrate was concentrated in vacuo to dryness. The residue was recrystallized from diethyl ether (20 mL) to afford 1′-(diphenylmethyl)-6-methoxy-5-methylspiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (7.9 g, 72%) as a colorless solid: 1H NMR (300 MHz, CDCl3) δ7.41-7.27 (m, 10H), 7.15 (dd, J=7.1, 1.5 Hz, 1H), 7.07 (s, 1H), 7.05-6.92 (m, 2H), 6.55-6.49 (m, 2H), 6.34 (s, 1H), 4.86 (ABq, 2H), 3.80 (s, 3H), 2.01 (s, 3H); 13C NMR (75 MHz, CDCl3) δ178.1, 160.2, 159.2, 141.8, 137.8, 137.4, 132.9, 128.70, 128.66, 128.48, 128.46, 128.2, 128.0, 127.9, 124.2, 123.8, 123.1, 119.6, 112.2, 93.8, 80.4, 58.7, 57.7, 55.6, 16.1; MS (ES+) m/z 448.3 (M+1).

Provenance & Evidence