Reaction Steps
Following the procedure as described in EXAMPLE 5 and making non-critical variations using (3R)-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one to replace 5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one, and 1-bromopentane to replace 5-(chloromethyl)-2-methoxypyrimidine, (3R)-1′-pentyl-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one was obtained (78%) as a colorless solid: mp 128-129° C. (diethyl ether); 1H NMR (300 MHz, CDCl3) δ7.33-7.26 (m, 1H), 7.17 (d, J=7.1 Hz, 1H), 7.07-7.02 (m, 1H), 6.91 (d, J=7.8 Hz, 1H), 6.49 (s, 1H), 6.41 (s, 1H), 4.92 (d, J=8.9 Hz, 1H), 4.67 (d, J=8.9 Hz, 1H), 8.64 (t, J=4.5 Hz, 2H), 3.87-3.63 (m, 2H), 2.99 (t, J=4.5 Hz, 2H), 1.79-1.69 (m, 2H), 1.40-1.35 (m, 4H), 0.94-0.89 (m, 3H); 13C NMR (75 MHz, CDCl3) δ177.5, 161.6, 161.2, 142.4, 133.0, 128.6, 123.8, 123.0, 120.3, 119.7, 118.7, 108.4, 93.1, 80.5, 72.3, 57.6, 40.3, 29.0, 27.1, 22.3, 13.9; MS (ES+) m/z 349.9 (M+1).
