反应详情

To a solution of 2-acetyl-4-tert-butoxy-3-oxo-butyric acid ethyl ester [0.325 g, Reference Example 46] in acetic acid (3 ml) was added hydrazine hydrate (71 μL). The mixture was stirred at ambient temperature for 16 hours and then evaporated to remove the acetic acid. The residue was dissolved in ethyl acetate and the solution was washed with 5% sodium hydrogen carbonate solution, then with water, then dried over magnesium sulfate, and then evaporated to yield 3-tert-butyloxymethyl-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (0.258 g) as a yellow oil which was used without further purification. LC-MS (METHOD B): RT=3.22 minutes; 241 (M+H)+.

1. customevaporated
2. customto remove the acetic acid
3. dissolutionThe residue was dissolved in ethyl acetate
4. washthe solution was washed with 5% sodium hydrogen carbonate solution
5. dry with materialwith water, then dried over magnesium sulfate
6. customevaporated