Reaction Steps
To an oven-dried flask was charged with [6-(dimethylamino)pyridin-3-yl]boronic acid (37.0 mg, 0.17 mmol), Pd(PPh3)4 (13.5 mg, 0.012 mmol) followed by flashing with nitrogen. To the flask was added a solution of 4′-bromo-1′-pentylspiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-2′(1′H)-one (50.0 mg, 0.12 mmol) in anhydrous dioxane (2.00 mL) followed by the addition of 2.0 M Na2CO3 (0.24 mL). The reaction mixture was heated at reflux for 48 h. After cooling down to ambient temperature, the solvent was removed under reduced pressure. The residue was diluted with ethyl acetate (2.00 mL), washed with saturated ammonium chloride (2.00 mL), and concentrated in vacuo to dryness. The residue was subjected to column chromatography to yield the title compounds: 1H NMR (300 MHz, CDCl3) δ 7.77 (d, 1H), 7.32 (t, 1H), 6.87 (dd, 2H), 6.71 (dd, 1H), 6.23 (d, 1H), 6.20 (s, 1H), 5.88 (d, 2H), 4.56 (ABq, 2H), 3.89-3.80 (m, 1H, 3.69-3.59 (m, 1H), 3.05 (s, 6H), 1.78-1.69 (m, 2H), 1.39-1.35 (m, 4H), 0.90 (t, 3H); 13C NMR (75 MHz, CDCl3) δ 177.9, 158.3, 156.1, 148.8, 147.3, 142.9, 142.0, 137.8, 137.2, 129.9, 128.9, 125.6, 122.0, 121.0, 107.6, 104.3, 102.5, 101.5, 93.6, 77.8, 58.5, 40.5, 38.2, 29.1, 27.2, 22.4, 14.0; MS (ES+, m/z) 472.0 (M+1).
