Benzyl Bromide → 4'-(benzyloxy)-1'-methyl-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3'-indol]-2'(1'H)-one

Participants

Reaction Steps

4′-Hydroxy-1′-methyl-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one (0.25 g, 0.77 mmol), benzyl bromide (0.13 mL, 1.1 mmol), and cesium carbonate (0.751 g, 2.30 mmol) were combined in anhydrous N,N-dimethylformamide (10 mL) at ambient temperature and stirred for 16 h. The reaction mixture was concentrated in vacuo and the residue was taken up in water (25 mL) and extracted with dichloromethane (3×25 mL). The organic layer was dried over magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography and eluted with a 0% to 10% gradient of ethyl acetate in dichloromethane, followed by recrystallization from methanol/dichloromethane to afford 4′-(benzyloxy)-1′-methyl-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one (0.130 g, 41%) as a colorless solid: mp 198-200° C.; 1H NMR (300 MHz, DMSO-d6) δ 7.32-7.23 (m, 4H), 7.03-7.01 (m, 2H), 6.81 (d, J=8.5 Hz, 1H) 6.74 (d, J=7.8 Hz, 1H), 6.44 (s, 1H), 6.20 (s, 1H), 5.06 (s, 2H), 4.70 (ABq, 2H), 4.19-4.11 (m, 4H), 3.16 (s, 3H); 13C NMR (75 MHz, DMSO-d6) δ 177.4, 155.8, 154.4, 145.0, 144.3, 137.8, 137.3, 130.6, 128.5, 127.9, 127.0, 120.5, 117.6, 111.5, 108.1, 102.8, 98.8, 77.5, 69.1, 64.7, 64.1, 57.7, 27.1; MS (ES+) m/z 416.0 (M+1).

Provenance & Evidence