Reaction Steps
Following the procedure as described in EXAMPLE 10, and making non-critical variations using 5,5-dimethyl-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one to replace spiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-2′(1′H)-one, and tert-butyl 4-(tosyloxymethyl)piperidine-1-carboxylate to replace 4-fluorobenzyl bromide, the title compound was obtained in 70% yield: mp 65-75° C.; 1H NMR (300 MHz, CDCl3) δ 7.30 (td, 1H), 7.18 (d, 1H), 7.05 (t, 1H), 6.89 (d, 1H), 6.38 (s, 1H), 6.28 (s, 1H), 4.88 (d, 1H), 4.64 (d, 1H), 4.18 (s, 2H), 4.17-4.01 (br, 2H), 3.74-3.53 (m, 2H), 2.74-2.59 (m, 2H), 2.11-1.92 (m, 1H), 1.70-1.59 (m, 2H), 1.43 (s, 9H), 1.37-1.19 (m, 2H), 1.17 (s, 3H), 1.14 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 178.0, 161.3, 161.0, 154.7, 142.8, 132.6, 129.9, 128.7, 124.2, 123.3, 120.3, 116.2, 108.5, 93.4, 85.4, 80.6, 79.5, 57.7, 45.7, 41.3, 35.0, 30.0, 28.4, 27.8, 27.5; MS (ES+) m/z 527.5 (M+23).
