Reaction Steps
Following the procedure as described in PREPARATION 13A, and making non-critical variations using 4-methyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-7-ol to replace chroman-7-ol, and 1-[(2R)-tetrahydrofuran-2-ylmethyl]-1H-indole-2,3-dione to replace 1-(diphenylmethyl)indoline-2,3-dione, 3-hydroxy-3-(7-hydroxy-4-methyl-3,4-dihydro-2H-1,4-benzoxazin-6-yl)-1-[(2R)-tetrahydrofuran-2-ylmethyl]-1,3-dihydro-2H-indol-2-one was obtained (91%) as a pale grey solid: 1H NMR (300 MHz, CDCl3) (diastereomers) δ 8.94 (s, 0.4H), 8.80 (s, 0.6H), 7.52-7.48 (m, 1H), 7.41-7.34 (m, 1H), 7.20-7.08 (m, 2H), 6.52 (s, 1H), 6.16 (s, 1H), 4.51 (s, 0.4H), 4.44 (s, 0.6H), 4.29-4.17 (m, 3H), 3.90-3.64 (m, 4H), 3.17-2.99 (m, 2H), 2.58 (s, 3H), 2.04-1.78 (m, 3H), 1.74-1.60 (m, 1H); 13C NMR (diastereomers) (75 MHz, CDCl3) δ179.4, 179.2, 149.4, 149.3, 146.2, 143.2, 143.0, 130.2, 130.1, 129.8, 129.6, 125.9, 125.7, 123.6, 123.5, 117.6, 112.7, 112.4, 110.4, 110.3, 107.4, 79.3, 79.2, 76.9, 76.7, 68.3, 68.2, 65.3, 49.5, 44.7, 44.6, 39.5, 29.3, 29.1, 25.7, 25.6; MS (ES+) m/z 419.1 (M+23).
