Reaction Steps
1′-[(4-Benzylmorpholin-2-yl)methyl]-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one (0.19 g, 0.41 mmol) was suspended in methanol (20 mL) and ethyl acetate (20 mL) in a steel bomb, then 20% palladium hydroxide on carbon (0.03 g, 0.04 mmol) was added. Hydrogenation was done at 120 psi in the steel bomb for 16 h. The reaction mixture was filtered through a pad of celite, and the filtrate was concentrated to dryness. The residue was purified by column chromatography (ethyl acetate/methanol/ammonia, 10:1:0.1) to afford 1′-[(4-methylmorpholin-2-yl)methyl]-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1H)-one (0.015 g, 10%) as a colorless foam as the first fraction: 1H NMR (300 MHz, CDCl3) δ7.34-7.25 (m, 1H), 7.17-6.99 (m, 3H), 6.48 (s, 0.5H), 6.44 (s, 0.5H), 6.39 (s, 1H), 4.94-4.88 (m, 1H), 4.69-4.63 (m, 1H), 4.52 (t, J=8.7 Hz, 2H), 4.00-3.55 (m, 5H), 2.97 (t, J=8.7 Hz, 2H), 2.76 (d, J=8.4 Hz, 1H), 2.60 (d, J=8.4 Hz, 1H), 2.26 (s, 3H), 2.18-1.88 (m, 2H); 13C NMR (75 MHz, CDCl3) δ 178.1, 178.0, 161.8, 161.7, 161.2, 161.18, 142.7, 142.67, 132.7, 132.6, 128.7, 128.6), 123.7, 123.6, 123.3, 123.2, 120.4, 120.3, 119.8, 119.7, 118.9, 118.8, 109.6, 109.4, 93.2, 93.16, 80.5, 80.4, 73.7, 73.6, 72.3, 66.8, 66.6, 58.3 58.0, 57.6, 54.7, 54.6, 46.4, 46.3, 43.2, 43.17, 29.0; MS (ES+) m/z 393.0 (M+1), and 1-(morpholin-2-ylmethyl)-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one (0.04 g, 26%) as a colorless foam as the second fraction: MS (ES+) m/z 379.0 (M+1).
