Reaction Steps
5-(3,5-dimethylisoxazol-4-yl)indoline-2,3-dione (242 mg, 1.0 mmol) is dissolved in MeOH (20 ml), cyclohexanone (196 mg, 2.0 mmol) and dimethylamine (0.4 mmol) are added and the reaction mixture is stirred for 4 h at room temperature. After that, the mixture is concentrated in vacuo and the residue was purified with chromatography on column to give two isomers (The first 50 mg, 14.7%, the second 30 mg, 8.8% and mixture 100 mg, 29.3%). The fast isomer (50 mg, 14.7%): 1H NMR (400 MHz, DMSO-d6): δ 10.25 (s, 1H), 7.29 (d, J=1.6 Hz, 1H), 7.17 (dd, J=1.6, 8.0 Hz, 1H), 6.84 (d, J=8.0 Hz, 1H), 5.83 (s, 1H), 3.32-3.41 (m, 1H), 2.30-2.40 (m, 5H), 2.19 (s, 3H), 1.98-2.06 (m, 2H), 1.80-1.83 (m, 2H), 1.44-1.64 (m, 2H), MS (ESI) m/e [M+1]+ 341.0; the slow isomer (30 mg, 8.8%): 1H NMR (400 MHz, DMSO-d6): δ 10.31 (s, 1H), 7.16-7.20 (m, 2H), 6.88 (d, J=8.0 Hz, 1H), 5.92 (s, 1H), 3.08-3.12 (m, 1H), 2.59-2.62 (m, 1H), 2.36 (s, 3H), 2.29-2.35 (m, 1H), 2.19 (s, 3H), 1.77-2.00 (m, 4H), 1.62-1.68 (m, 1H), 1.42-1.50 (m, 1H), MS (ESI) m/e [M+1]+ 341.
