反应详情

To a solution 3-Amino-1-methyl-pyrazole (1.39 g, 14.3 mmol, 3.5 equiv.) in 25 ml of dry dioxane were added 7.17 ml of a 2M solution of trimethyl aluminium in hexane (14.3 mmol, 3.5 equiv.) and the mixture was stirred for 1 h at r.t. Then 3-Bromo-6-methyl-pyridine-2-carboxylic acid ethyl ester (1.00 g, 4.1 mmol) were added and the reaction was refluxed for 2 h. After allowing the reaction to cool to r.t., the reaction was quenched with water (0.5 ml), stirred for 10 min, dried by addition of magnesium sulfate and filtered over Dicalite which was further washed with methylene chloride. The filtrate was concentrated in vaccuo. The residue (1.66 g, yellow oil) was purified by flash chromatography (heptane/ethyl acetate 2:3) to yield the title compound as a yellow solid (total 0.99 g, 82%), MS (ISP): m/e=295.2, 297.2 (M+H+).

1. temperaturethe reaction was refluxed for 2 h
2. customthe reaction
3. temperatureto cool to r.t.
4. customthe reaction was quenched with water (0.5 ml)
5. stirringstirred for 10 min
6. dry with materialdried by addition of magnesium sulfate
7. filtrationfiltered over Dicalite which
8. washwas further washed with methylene chloride
9. concentrationThe filtrate was concentrated in vaccuo
10. customThe residue (1.66 g, yellow oil) was purified by flash chromatography (heptane/ethyl acetate 2:3)