Reaction Steps
Following the procedure as described in EXAMPLE 12 and making non-critical variations using 2,4-dimethylaniline 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-(2,4-dimethylphenyl)-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 (90%) as a colorless solid: mp 207-208° C.; 1H NMR (300 MHz, DMSO-d6) δ9.95 (s, 1H), 7.69-7.61 (m, 1H), 7.49-7.34 (m, 2H), 7.31-7.13 (m, 4H), 7.09-6.95 (m, 3H), 6.89 (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), 4.71 (d, J=8.9 Hz, 1H), 4.47 (t, J=8.7 Hz, 2H), 2.93 (t, J=8.7 Hz, 2H), 2.25 (s, 6H); 13C NMR (75 MHz, DMSO-d6) δ177.9, 167.7, 161.6, 161.2, 142.8, 136.6, 135.6, 134.4, 133.9, 133.5, 132.7, 131.3, 130.8, 129.1, 128.4, 127.8, 126.9, 126.7, 124.2, 123.6, 120.9, 120.4, 119.6, 109.7, 92.9, 80.4, 72.6, 65.4, 57.5, 41.4, 28.8, 21.0, 18.4, 15.6; MS (ES+) m/z 517.2 (M+1).
