Reaction Steps
Following the procedure as described in EXAMPLE 12 and making non-critical variations using 2-ethylaniline to replace cyclohexanemethylamine, and 2-[(2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)methyl]benzoic acid to replace 3-[(2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)methyl]benzoic acid, N-(2-ethylphenyl)-2-[(2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)methyl]benzamide was obtained (95%) as a colorless solid: mp 184-186° C.; 1H NMR (300 MHz, DMSO-d6) δ10.06 (s, 1H), 7.69-7.61 (m, 1H), 7.50-7.34 (m, 3H), 7.31-7.13 (m, 6H), 7.01 (dd, J=7.5, 7.5 Hz, 1H), 6.90 (d, J=7.8 Hz, 1H), 6.53 (s, 1H), 6.40 (s, 1H), 5.20-5.01 (m, 2H), 4.86 (d, J=8.9 Hz, 1H), 4.72 (d, J=8.9 Hz, 1H), 4.47 (t, J=8.7 Hz, 2H), 2.93 (t, J=8.7 Hz, 2H), 2.68 (q, J=7.5 Hz, 2H), 1.16 (t, J=7.5 Hz, 3H); 13C NMR (75 MHz, DMSO-d6) δ177.9, 168.1, 161.6, 161.2, 142.8, 139.8, 136.4, 135.8, 134.5, 132.7, 130.8, 129.1, 129.0, 128.3, 127.9, 127.8, 127.0, 126.9, 126.5, 124.2, 123.6, 120.9, 120.4, 119.6, 109.7, 92.9, 80.4, 72.6, 57.5, 41.4, 28.8, 24.5, 14.8; MS (ES+) m/z 517.2 (M+1).
