Reaction Steps
Following the procedure as described in EXAMPLE 12 and making non-critical variations using methylamine hydrochloride 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-methyl-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 (86%) as a colorless solid: 1H NMR (300 MHz, CDCl3) δ7.71 (d, J=8.0 Hz, 2H), 7.34 (d, J=8.0 Hz, 2H), 7.22-7.12 (m, 2H), 7.02 (t, J=7.6 Hz, 1H), 6.73 (d, J=7.6 Hz, 1H), 6.57-6.45 (m, 1H), 6.42 (s, 1H), 6.39 (s, 1H), 4.95 (ABq, 2H), 4.81 (ABq, 2H), 4.53-4.34 (m, 2H), 2.95 (d, J=4.0 Hz, 3H), 2.90-2.73 (m, 2H); 13C NMR (75 MHz, CDCl3) δ178.2, 167.5, 161.9, 161.4, 141.8, 139.0, 134.2, 132.5, 128.8, 127.6, 127.4, 124.0, 123.7, 120.0, 119.8, 118.7, 109.2, 93.3, 80.6, 72.4, 57.7, 43.8, 28.9, 26.8; MS (ES+) m/z 427.1 (M+1).
