反应详情

温度

0 °C

3-(4-methyl-2-thienyl)-1H-pyrazole (9.0 mmol) was dissolved in 20 mL dry N,N-dimethylformamide and cooled to 0° C. under argon atmosphere. Sodium hydride (13.5 mmol, 60% dispersion in mineral oil) was added in portions at 0° C. The reaction mixture was allowed to warm to room temperature and was stirred at room temperature for 15 min. After cooling to 0° C. again, 2-iodopropane (18.0 mmol) was added dropwise at 0° C. The reaction mixture was stirred at room temperature for 14 h. Water and MTBE were added to the reaction mixture. The phases were separated and the aqueous phase was extracted with MTBE. The combined organic extracts were successively washed with water and brine, dried over MgSO4, filtered and concentrated. The residue was purified by chromatography on silica gel (cyclohexane:dichloromethane 100:0 to 0:100, then cyclohexane:ethyl acetate 100:0 to 0:100) to afford 1.15 g 1-isopropyl-3-(4-methyl-2-thienyl)-1H-pyrazole (62% yield) and 305 mg of 1-isopropyl-5-(4-methyl-2-thienyl)-1H-pyrazole (16% yield).

1. temperatureto warm to room temperature
2. temperatureAfter cooling to 0° C. again
3. stirringThe reaction mixture was stirred at room temperature for 14 h
4. customThe phases were separated
5. extractionthe aqueous phase was extracted with MTBE
6. washThe combined organic extracts were successively washed with water and brine
7. dry with materialdried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated
10. customThe residue was purified by chromatography on silica gel (cyclohexane:dichloromethane 100:0 to 0:100