Reaction Steps
Following the procedure as described in EXAMPLE 4 and making non-critical variations using 5-(bromomethyl)-2,1,3-benzooxadiazole 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, 1′-(2,1,3-benzoxadiazol-5-ylmethyl)-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one was obtained (44%) as a colorless solid: mp 164-166° C.; 1H NMR (300 MHz, CDCl3) δ7.86 (d, J=9.3 Hz, 1H), 7.75 (s, 1H), 7.43-7.37 (m, 1H), 7.25-7.19 (m, 2H), 7.08 (dd, J=7.5, 7.5 Hz, 1H), 6.82 (d, J=7.8 Hz, 1H), 6.53 (s, 1H), 6.23 (s, 1H), 5.13 (d, J=16.2 Hz, 1H), 4.95 (d, J=9.0 Hz, 1H), 4.94 (d, J=16.2 Hz, 1H), 4.70 (d, J=9.0 Hz, 1H), 4.24-4.10 (m, 4H); 13C NMR (75 MHz, CDCl3) δ177.7, 155.3, 149.0, 148.7, 144.8, 141.4, 139.7, 138.4, 132.0, 131.4, 129.0, 124.3, 124.0, 120.6, 117.8, 113.9, 111.4, 108.8, 99.6, 80.1, 64.5, 63.9, 58.0, 44.0; MS (ES+) m/z 427.9 (M+1).
