反应详情

2-Ethyl-2H-pyrazole-3,4-dicarboxylic acid diethyl ester (280 mg, 1.2 mmol) was suspended in a NaOH solution (0.5M in water, 2.8 ml) and stirred at r.t. until HPLC analysis indicated the consumption of the starting material (4 h). HCl (1N, 1 ml) was added, and the mixture was extracted with ethyl acetate. The combined organic layers were dried (Na2SO4), evaporated, and the title compound (200 mg, 81%) was isolated from the mixture by column chromatography (silica gel, heptane:ethyl acetate=100:0-60:40). MS (m/e)=211.1 [M−H+].

1. customthe consumption of the starting material (4 h)
2. additionHCl (1N, 1 ml) was added
3. extractionthe mixture was extracted with ethyl acetate
4. dry with materialThe combined organic layers were dried (Na2SO4)
5. customevaporated