Reaction Steps
Following the procedure as described in EXAMPLE 2.46 and making non-critical variations using 3-furanboronic acid to replace quinolin-3-ylboronic acid, and 4′-bromo-1′-methylspiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-2′(1′H)-one to replace 4′-bromo-1′-(diphenylmethyl)-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one, 4′-furan-3-yl-1′-methyl-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one was obtained (65%) as a colorless solid: mp 178-180° C. (ethyl acetate/hexanes); 1H NMR (300 MHz, CDCl3) δ 7.38-7.29 (m, 2H), 7.00 (d, J=7.9 Hz, 1H), 6.86 (d, J=7.8 Hz, 1H), 6.76 (s, 1H), 6.41 (s, 1H), 6.28 (s, 1H), 6.04-6.01 (m, 1H), 4.68 (d, J=9.0 Hz, 1H), 4.53 (d, J=9.0 Hz, 1H), 4.23-4.09 (m, 4H), 3.26 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 178.0, 155.5, 144.7, 144.3, 142.8, 140.5, 137.9, 130.8, 129.1, 128.1, 125.2, 122.6, 122.5, 111.2, 111.1, 107.4, 99.7, 76.7, 64.6, 64.0, 58.3, 26.8; MS (ES+) m/z 375.9 (M+1).
