Reaction Steps
Following the procedure as described in EXAMPLE 4 and making non-critical variations using 5-fluoro-6-methoxyspiro[1-benzofuran-3,3′-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, and benzylbromide to replace 2-(bromomethyl)tetrahydro-2H-pyran, 1′-benzyl-5-fluoro-6-methoxyspiro[1-benzofuran-3,3′-indol]-2′(1′H)-one was obtained (86%) as a colorless solid: mp 160-162° C.; 1H NMR (300 MHz, CDCl3) δ7.39-7.26 (m, 5H), 7.20 (ddd, J=7.6, 7.6, 1.2 Hz, 1H), 7.16-7.09 (m, 1H), 7.06-6.97 (m, 1H), 6.79 (d, J=7.8 Hz, 1H), 6.61 (d, J=6.8 Hz, 1H), 6.43 (d, J=10.1 Hz, 1H), 5.05 (d, J=15.5 Hz, 1H), 4.99 (d, J=9.0 Hz, 1H), 4.83 (d, J=15.5 Hz, 1H), 4.70 (d, J=9.0 Hz, 1H), 3.86 (s, 3H); 13C NMR (75 MHz, CDCl3) δ182.3, 173.3, 166.3, 165.6, 147.9, 137.5, 133.7, 128.5, 128.0, 126.1, 124.9, 124.6, 114.2, 97.5, 84.9, 77.3, 62.0, 47.6, 33.5; MS (ES+) m/z 376.0 (M+1).
