Reaction Steps
Following the procedure as described in EXAMPLE 12 and making non-critical variations using heptylamine 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-heptyl-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 (75%) as a colorless solid: mp 196-198° C.; 1H NMR (300 MHz, DMSO-d6) δ8.53 (t, J=5.5 Hz, 1H), 7.46-7.27 (m, 3H), 7.23-7.06 (m, 3H), 6.99 (dd, J=7.5, 7.5 Hz, 1H), 6.84 (d, J=7.7 Hz, 1H), 6.51 (s, 1H), 6.40 (s, 1H), 5.10=-4.92 (m, 2H), 4.85 (d, J=9.4 Hz, 1H), 4.71 (d, J=9.4 Hz, 1H), 4.55-4.39 (m, 2H), 3.23 (q, J=6.8 Hz, 2H), 3.03-2.84 (m, 2H), 1.59-1.44 (m, 2H), 1.38-1.14 (m, 8H), 0.81 (t, J=6.6 Hz, 1H); 13C NMR (75 MHz, DMSO-d6) δ177.8, 168.7, 161.6, 161.2, 142.8, 136.9, 134.1, 132.6, 130.4, 129.1, 128.1, 127.8, 126.8, 124.1, 123.6, 120.9, 120.3, 119.6, 109.6, 92.9, 80.4, 72.6, 57.4, 41.3, 31.7, 29.4, 28.9, 28.8, 26.9, 22.5, 14.4; MS (ES+) m/z 511.2 (M+1).
