Reaction Steps
Following the procedure as described in EXAMPLE 12 and making non-critical variations using 2-ethylaniline to replace cyclohexanemethylamine, and 4-[(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)-4-[(2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)methyl]benzamide was obtained (49%) as a colorless solid: mp 203-204° C.; 1H NMR (300 MHz, CDCl3) δ7.96-7.83 (m, 3H), 7.69 (s, 1H), 7.52-7.44 (m, 2H), 7.31-7.13 (m, 5H), 7.10-7.02 (m, 1H), 6.82-6.74 (m, 1H), 6.49 (s, 1H), 6.44 (s, 1H), 5.03 (ABq, 2H), 4.86 (ABq, 2H), 4.60-4.51 (m, 2H), 3.11-2.92 (m, 2H), 2.67 (q, J=7.5 Hz, 2H), 1.27 (t, J=7.5 Hz, 3H); 13C NMR (75 MHz, CDCl3) δ 178.0, 165.2, 161.9, 161.3, 141.8, 139.8, 135.1, 134.9, 134.6, 132.7, 128.8, 128.6, 127.8, 127.7, 126.8, 125.8, 124.1, 123.7, 120.0, 119.9, 118.8, 109.1, 93.3, 80.6, 72.4, 57.7, 43.8, 29.0, 24.4, 14.0; MS (ES+) m/z 517.2 (M+1).
