反应详情

温度

82 °C

A mixture of 3-methylpyrazole (500 mg, 6.09 mmol), salicylaldoxime (167 mg, 1.22 mmol), copper (I) oxide (44 mg, 0.30 mmol), and cesium carbonate (3.97 g, 12.2 mmol) was sparged with argon for 3 minutes. To this mixture was added acetonitrile (3 ml) and 2-bromothiophene (0.88 ml, 9.1 mmol). The reaction mixture was sparged with argon for 3 minutes and heated to 82° C. After 16 hours, the reaction mixture was diluted with ethyl acetate, washed with water and brine, then dried over magnesium sulfate, filtered, and concentrated. The residue was purified by column chromatography on silica gel (ethyl acetate/hexanes gradient) to afford 3-methyl-1-(2-thienyl)-1H-pyrazole (faster eluting isomer) and 5-methyl-1-(2-thienyl)-1H-pyrazole (slower eluting isomer).

1. customwas sparged with argon for 3 minutes
2. customThe reaction mixture was sparged with argon for 3 minutes
3. additionthe reaction mixture was diluted with ethyl acetate
4. washwashed with water and brine
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated
8. customThe residue was purified by column chromatography on silica gel (ethyl acetate/hexanes gradient)