反应详情

温度

80 °C

To a stirred solution of ethyl 1-methyl-1H-pyrazole-3-carboxylate (5 g, 32.4 mmol) in CH3CN (200 mL) under Ar was added I2 (4.94 g, 19.46 mmol) and after 5 min CAN (10.67 g, 19.46 mmol). The reaction mixture was stirred for 1 hr at 80° C., concentrated, quenched with a 10% aq. Na2S2O3 solution, and extracted with CH2Cl2. The combined organic layers were washed with brine, dried over Na2SO4 and evaporated. The crude material was purified by silica gel column chromatography (hexane/EtOAc 25-45%) to afford the title product (9.04 g, 32.3 mmol, 100% yield) as a white solid. tR: 3.78 min (HPLC 1); tR: 0.80 min (LC-MS 2); ESI-MS: 281 [M+H]+ (LC-MS 2); Rf=0.45 (hexane/EtOAc 1:1).

1. concentrationconcentrated
2. customquenched with a 10% aq. Na2S2O3 solution
3. extractionextracted with CH2Cl2
4. washThe combined organic layers were washed with brine
5. dry with materialdried over Na2SO4
6. customevaporated
7. customThe crude material was purified by silica gel column chromatography (hexane/EtOAc 25-45%)