Reaction Steps
Following the procedure as described in EXAMPLE 4 and making non-critical variations using 5-chloromethyl-2-isopropyloxazole to replace 2-(bromomethyl)tetrahydro-2H-pyran, and spiro[furo[2,3-f][1,3]benzodioxole-7,3′-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, 1′-[(2-isopropyl-1,3-oxazol-5-yl)methyl]spiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-2′(1′H)-one was obtained (11%) as a colorless solid: mp 75-77° C.; 1H NMR (300 MHz, CDCl3) δ7.42 (s, 1H), 7.26 (dd, J=7.4, 7.4 Hz, 1H), 7.15 (d, J=7.3 Hz, 1H), 7.07-7.00 (m, 2H), 6.48 (s, 1H), 6.15 (s, 1H), 5.83 (d, J=4.2 Hz, 2H), 4.83 (ABq, 2H), 4.78 (ABq, 2H), 3.10-2.95 (m, 1H), 1.30 (d, J=7.0 Hz, 6H); 13C NMR (75 MHz, DMSO-d6) δ177.3, 169.4, 155.8, 148.9, 142.3, 141.8, 135.3, 135.1, 132.2, 128.9, 123.8, 123.5, 119.5, 109.6, 103.1, 101.5, 93.6, 80.3, 58.2, 36.6, 28.5, 20.4, 20.3; MS (ES+) m/z 405.4 (M+1).
