Triphenylphosphine → 1'-(2-cyclopropylethyl)spiro[furo[2,3-f][1,3]benzodioxole-7,3'-indol]-2'(1'H)-one

Participants

Reaction Steps

To a solution of 1-(2-cyclopropylethyl)-3-(6-hydroxy-1,3-benzodioxol-5-yl)-3-(hydroxymethyl)-1,3-dihydro-2H-indol-2-one (0.92 g, 2.51 mmol) in anhydrous THF (20.0 mL) was added triphenylphosphine (0.82 g, 3.13 mmol) and diethyl azodicarboxylate (0.55, 3.13 mmol) at −78° C. The brown reaction solution was stirred at ambient temperature for 16 h, and quenched with saturated ammonium chloride (50.0 mL). The organic solvent was removed under reduced pressure and the aqueous mixture was extracted with ethyl acetate (3×50.0 mL). The combined organic layers were dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The brown residue was subjected to column chromatography eluting with ethyl acetate/hexane (5% to 20%, gradient) to give the title compound (0.63 g, 72%) which was crystallized from ether to afford a colorless solid: mp 125-127° C.; 1H NMR (300 MHz, CDCl3) δ 7.30-7.25 (m, 1H), 7.14 (d, 1H), 7.02 (t, 1H), 6.89 (d, 1H), 6.49 (s, 1H), 6.11 (s, 1H), 5.84 (m, 2H), 4.76 (m, 2H), 3.93-3.74 (m, 2H), 1.65-1.57 (m, 2H), 0.76-0.56 (m, 1H), 0.48-0.41 (m, 2H), 0.08-0.03 (m, 2H); 13C NMR (75 MHz, CDCl3) δ 177.4, 155.9, 148.8, 142.6, 142.3, 132.4, 128.8, 124.0, 123.1, 119.5, 108.6, 103.1, 101.5, 93.6, 80.6, 58.2, 40.5, 32.5, 30.8, 8.7, 4.4; MS (ES+) m/z 350.3 (M+1).

Provenance & Evidence