Cesium carbonate → HCID 59352082, compound

Participants

Reaction Steps

To a solution of 5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one (0.97 g, 3.46 mmol) in 2-butanone (25 mL) were added cesium carbonate (3.39 g, 10.39 mmol) and α-bromo-m-tolunitrile (0.85 g, 4.33 mmol). The mixture was heated to reflux for 2 h, cooled to ambient temperature, and filtered. The solid was washed with ethyl acetate. The filtrate was concentrated in vacuo, the residue was purified by column chromatography with ethyl acetate-hexanes (1:5-1:1), followed by recrystallization from ethyl acetate and ether to afford 3-[(2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)methyl]benzonitrile (1.26 g, 92%) as a colorless solid: mp 187-193° C.; 1H NMR (300 MHz, CDCl3) δ 7.61-7.58 (m, 3H), 7.47-7.44 (m, 1H), 7.25-7.19 (m, 2H), 7.07-7.03 (m, 1H), 6.73-6.71 (m, 1H), 6.43-6.41 (m, 2H), 5.11-4.70 (m, 4H), 4.53 (d, J=9.0 Hz, 2H), 3.09-2.91 (m, 2H); 13C NMR (75 MHz, CDCl3) δ 178.1, 162.0, 161.4, 141.5, 137.5, 132.6, 131.9, 131.6, 130.7, 129.9, 128.9, 124.3, 123.9, 120.2, 119.9, 118.7, 118.4, 113.1, 108.8, 93.4, 80.5, 72.5, 57.7, 43.4, 29.0; MS (ES+) m/z 394.8 (M+1).

Provenance & Evidence