Reaction Steps
Following the procedure as described in EXAMPLE 4 and making non-critical variations using α-bromo-m-tolunitrile to replace 2-(bromomethyl)tetrahydro-2H-pyran, and 2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one to replace 5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one, 3-[(2′-oxo-2,3-dihydrospiro[furo[2,3-g][1,4]-benzodioxine-8,3′-indol]-1′(2′H)-yl)methyl]benzonitrile was obtained (66%) as a colorless solid: mp 173-178° C. (ethyl acetate/diethyl ether); 1H NMR (300 MHz, CDCl3) δ 7.60-7.63 (m, 3H), 7.44-7.47 (m, 1H), 7.21-7.24 (m, 2H), 7.05 (t, J=7.5 Hz, 1H), 6.72 (d, J=7.5 Hz, 1H), 6.50 (s, 1H), 6.18 (s, 1H), 4.93-4.97 (m, 3H), 4.66-4.69 (m, 1H), 4.13-4.17 (m, 4H); 13C NMR (75 MHz, CDCl3) δ 177.7, 155.3, 144.8, 141.5, 138.4, 137.4, 132.1, 131.8, 131.7, 130.9, 129.9, 129.0, 124.3, 123.9, 120.7, 118.4, 113.1, 111.4, 108.8, 99.5, 80.1, 64.5, 63.9, 58.0, 43.4; MS (ES+) m/z 410.8 (M+1).