Reaction Steps
A suspension of 1′-(4-bromobenzyl)-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one (0.45 g, 1.0 mmol), morpholine (0.26 g, 3.0 mmol), dicyclohexyloxalylhydrazide (0.14 g, 0.5 mmol), tetrabutylammonium bromide (0.34 g, 1 mmol), copper (II) oxide (0.05 g, 0.6 mmol) and cesium carbonate (0.65 g, 2.0 mmol) was heated in microwave reactor at 130° C. for 10 min. The reaction mixture was concentrated under reduced pressure, and the residue was subjected to column chromatography with dichloromethane-methanol (100:1-10:1) to afford 1′-(4-morpholin-4-ylbenzyl)-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one as a colorless solid: 1H NMR (300 MHz, CDCl3) δ 7.35-6.74 (m, 8H), (0.09 g, 19%), 6.45 (s, 1H), 6.41 (s, 1H), 4.87 (ABq, 2H), 4.81 (ABq, 2H), 4.52 (t, J=8.7, 8.7 Hz, 2H), 4.01-3.74 (m, 4H), 3.25-3.07 (m, 4H), 3.05-2.90 (m, 2H); 13C NMR (75 MHz, CDCl3) δ 177.8, 161.8, 161.3, 142.1, 132.8, 128.6 (2C), 123.8, 123.3, 120.2, 119.9, 118.9, 116.0, 109.3, 93.2, 80.6, 72.3, 66.6, 57.7, 49.4, 43.6, 29.0; MS (ES+) m/z 454.87 (M+1).
