Reaction Steps
Following the procedure as described in EXAMPLE 9 and making non-critical variations using N-(3-bromopropyl)phthalimide to replace 2-(bromomethyl)-5-(trifluoromethyl)furan, and 5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one to replace 3-methylspiro[furo[3,2-f][1,2]benzisoxazole-5,3′-indol]-2′(1′H)-one, 2-[3-(2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)propyl]-1H-isoindole-1,3(2H)-dione was obtained (39%) as a pale yellow solid: mp 214-217° C.; 1H NMR (300 MHz, CDCl3) δ 7.84 (dd, J=5.6, 3.0 Hz, 2H), 7.72 (dd, J=5.5, 3.0 Hz, 2H), 7.31-7.28 (m, 1H), 7.18 (dd, J=7.4, 0.8 Hz, 1H), 7.04 (ddd, J=8.4, 7.5, 0.8 Hz, 1H), 6.88 (d, J=7.8 Hz, 1H), 6.58 (s, 1H), 6.40 (s, 1H), 4.94 (d, J=9.0 Hz, 1H), 4.69 (d, J=9.0 Hz, 1H), 4.53 (t, J=8.6 Hz, 2H), 3.98-3.89 (m, 1H), 3.85-3.75 (m, 3H), 3.01 (ddd, J=10.6, 8.4, 1.7 Hz, 2H), 2.20-2.10 (m, 2H); 13C NMR (75 MHz, CDCl3) δ177.7, 168.1, 161.7, 161.2, 141.9, 134.0, 133.0, 131.9, 128.7, 124.0, 123.3, 123.2, 120.2, 119.9, 118.9, 108.2, 93.1, 80.4, 72.4, 57.6, 38.0, 35.7, 29.0, 26.8; MS (ES+) m/z 466.9 (M+1).
