Reaction Steps
Following the procedure as described in EXAMPLE 9 and making non-critical variations using methyl 3-bromomethylbenzoate to replace 2-(bromomethyl)-5-(trifluoromethyl)furan, and 2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one to replace 3-methylspiro[furo[3,2-f][1,2]benzisoxazole-5,3′-indol]-2′(1′H)-one, methyl 3-[(2′-oxo-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-1′(2′H)-yl)methyl]benzoate was obtained (99%) as a colorless solid: mp 89-97° C. (ethyl acetate/diethyl ether); 1H NMR (300 MHz, CDCl3) δ 7.98-7.95 (m, 2H), 7.51-7.42 (m, 2H), 7.19-7.14 (m, 2H), 7.03-7.01 (m, 1H), 6.73-6.70 (m, 1H), 6.50 (s, 1H), 6.27 (s, 1H), 5.19-5.13 (m, 1H), 4.95-4.92 (m, 1H), 4.84-4.79 (m, 1H), 4.67-4.64 (m, 1H), 4.19-4.11 (m, 4H), 3.90 (s, 3H) 13C NMR (75 MHz, CDCl3) δ 177.6, 166.7, 153.3, 144.7, 141.7, 138.4, 136.1, 132.3, 131.7, 130.8, 129.2, 128.9, 128.1, 124.0, 123.6, 120.9, 111.6, 109.2, 99.4, 80.2, 64.5, 63.9, 58.1, 52.3, 43.8, 29.7; MS (ES+) m/z 443.8 (M+1).
