Reaction Steps
Following the procedure as described in EXAMPLE 12 and making non-critical variations using 2-thiopheneethylamine 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, 4-[(2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)methyl]-N-(2-thiophen-2-ylethyl)benzamide was obtained (74%) as a colorless solid: 1H NMR (300 MHz, CDCl3) δ7.71 (d, J=7.9 Hz, 2H), 7.37 (d, J=7.9 Hz, 2H), 7.24-7.13 (m, 3H), 7.04 (dd, J=7.5, 7.5 Hz, 1H), 6.95 (dd, J=5.0, 3.5 Hz, 1H), 6.86 (d, J=3.5 Hz, 1H), 6.74 (d, J=7.6 Hz, 1H), 6.51-6.46 (m, 1H), 6.46 (s, 1H), 6.42 (s, 1H), 4.97 (ABq, 2H), 4.83 (ABq, 2H), 4.52 (t, J=8.6 Hz, 2H), 3.78-3.57 (m, 2H), 3.13 (t, J=6.2 Hz, 2H), 2.95 (t, J=8.6 Hz, 2H); 13C NMR (75 MHz, CDCl3) δ 177.9, 166.8, 161.8, 161.3, 141.7, 141.1, 139.2, 134.1, 132.5, 128.7, 127.5, 127.4, 127.0, 125.4, 123.9 (2C), 123.6, 119.9 (2C), 118.7, 109.0, 93.2, 80.5, 72.3, 57.6, 43.7, 41.2, 29.8, 28.9; MS (ES+) m/z 523.1 (M+1).
