Reaction Steps
A mixture of 4′-bromo-1′-pentylspiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-2′(1′H)-one (0.28 g, 0.65 mmol), tetrakis(triphenylphosphine)palladium(0) (0.08 g, 10 mole %), triethylamine (0.33 g, 0.50 mL, 3.25 mmol) and 2-aminopyridine (0.12 g, 1.30 mmol) in N,N-dimethylformamide (5.00 mL) was subjected to carbon monoxide (40 Psi). The reaction mixture was heated at 80° C. for 16 h. After cooling down to ambient temperature, the reaction mixture was diluted with ethyl acetate (20.0 mL), washed with water (3×20.0 mL), brine (2×20.0 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The residue was subjected to column chromatography to give the title compound (0.04 g, 14%) as a solid: 1H NMR (300 MHz, CDCl3) δ 8.52 (d, 1H), 7.87 (br, 1H), 7.69-7.62 (m, 3H), 7.53-7.51 (m, 1H), 7.47-7.38 (m, 3H), 7.04-6.98 (m, 1H), 5.79 (d, 2H), 4.97 (ABq, 2H), 3.84-3.66 (m, 2H), 1.77-1.67 (m, 2H), 1.38-1.33 (m, 4H), 0.90 (t, 3H); 13C NMR (75 MHz, CDCl3) δ 177.5, 158.2, 156.7, 149.2, 143.5, 142.1, 132.2, 132.0, 131.9, 131.8, 129.6, 128.6, 128.4, 121.8, 118.2, 110.7, 102.0, 101.4, 93.9, 79.5, 77.2, 58.5, 40.6, 29.0, 27.0, 22.3, 14.0; MS (ES+) m/z 473.2 (M+2).
