反应详情

温度

80 °C

To a 100 mL round-bottomed flask were added a stir bar, 4-methoxy-o-phenylenediamine bis-hydrochloride salt (2 g, 9.5 mmol), acetonitrile (20 mL), triethylamine (2.6 mL, 19 mmol), and 3,3-dimethyldihydrofuran-2,5-dione (1.2 g, 9.5 mmol). After 1 h, the mixture was concentrated to dryness and ethanol (50 mL) followed by HCl (1 mL, 12 N) was added to the residue. The reaction vessel was heated at 80° C. for 12 hours before cooling to RT. The reaction mixture was concentrated to dryness. The residue was diluted with water (50 mL) and neutralized with sat. NaHCO3 until pH was 6.8-7. The aqueous was extracted with diethyl ether (3×100 mL), the combined extracts dried over sodium sulfate, filtered and concentrated to dryness. The residue was subjected to FCC to give the title compound (1.5 g, 57%). MS (ESI): mass calcd. for C15H20N2O3, 276.15; m/z found, 277.1 [M+H]+. A mixture of two tautomers observed so peaks are listed for identification purposes only. 1H NMR (600 MHz, DMSO-d6) δ 11.99-11.85 (m), 7.39 (d, J=8.7), 7.29 (d, J=8.6), 7.07 (d, J=2.4), 6.92 (d, J=2.4), 6.75 (dd, J=8.6, 2.4), 6.72 (dd, J=8.7, 2.4), 4.13-4.02 (m), 3.78-3.74 (m), 3.00-2.94 (m), 1.24-1.21 (m), 1.13 (t, J=7.1).

1. additionTo a 100 mL round-bottomed flask were added a stir bar
2. concentrationthe mixture was concentrated to dryness and ethanol (50 mL)
3. additionwas added to the residue
4. temperaturebefore cooling to RT
5. concentrationThe reaction mixture was concentrated to dryness
6. additionThe residue was diluted with water (50 mL)
7. extractionThe aqueous was extracted with diethyl ether (3×100 mL)
8. dry with materialthe combined extracts dried over sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated to dryness