反应详情

温度

60 °C

To a solution of (2,3-bis{[2-(methyloxy)ethyl]oxy}phenyl)acetonitrile (0.93 g, 3.52 mmol) in THF (20 mL) was added sodium hydride (0.42 g, 10.56 mmol) and ethyl acetate (1.55 g, 17.60 mmol), and the mixture was stirred at 60° C. for 90 min. After cooling to 0° C., water was added (50 mL), the aqueous layer was washed with dichloro-methane (3×25 mL), acidified with 1N HCl to pH 3, and extracted with ethyl acetate (3×50 mL). The ethyl acetate layer was washed with brine (50 mL), dried with sodium sulfate, and concentrated to give a yellow oil. This oil was dissolved in dry ethanol (5 mL), and hydrazine dihydrochloride (0.44 g, 4.20 mmol) and triethylamine (0.22 g, 2.10 mmol) were added. The reaction mixture was refluxed for 90 min, cooled to rt, and added into sat. sodium bicarbonate (100 mL). The aqueous layer was extracted with dichloromethane (3×50 mL), the organic layer was dried with sodium sulfate, and concentrated. Column chromatography on silica (95:5 dichloromethane/methanol) afforded 4-(2,3-bis{[2-(methyloxy)ethyl]oxy}phenyl)-3-methyl-1H-pyrazol-5-amine (0.81 g, 71% yield) as a pale yellow oil. 1H NMR (400 MHz, d4-methanol) δ7.08 (t, 1H), 6.97 (dd, 1H), 6.85 (dd, 1H), 4.18 (m, 2H), 3.90 (m, 2H), 3.78 (m, 2H), 3.47 (m, 2H), 3.43 (s, 3H), 3.23 (s, 3H), 2.19 (s, 3H).

1. temperatureAfter cooling to 0° C.
2. washthe aqueous layer was washed with dichloro-methane (3×25 mL)
3. extractionextracted with ethyl acetate (3×50 mL)
4. washThe ethyl acetate layer was washed with brine (50 mL)
5. dry with materialdried with sodium sulfate
6. concentrationconcentrated
7. customto give a yellow oil
8. temperatureThe reaction mixture was refluxed for 90 min
9. temperaturecooled to rt
10. extractionThe aqueous layer was extracted with dichloromethane (3×50 mL)
11. dry with materialthe organic layer was dried with sodium sulfate
12. concentrationconcentrated