反应详情

温度

0 °C

Sulfuric acid (7.77 mL, 146 mmol) was added to a solution of 2-(4-chloro-3-methyl-1H-pyrazol-1-yl)-6-methylaniline (1.9 g, 8.57 mmol) in concentrated hydrogen chloride (2.056 mL, 25.7 mmol) at 0° C. The solution was stirred and after cooling back to 0° C., sodium nitrite (0.591 g, 8.57 mmol) in water (3.5 mL) was added dropwise. The reaction was stirred 40 min at 0° C. before potassium iodide (2.85 g, 17.14 mmol) in water (3.5 mL) was added dropwise and then the solution was stirred at RT. After 1 h, the reaction is poured into ice with EtOAc and separated. The aqueous layer was extracted with EtOAc. The combined organic extracts were washed with 1N HCl, water, saturated sodium bicarbonate, 1N sodium sulfite, and dried over sodium sulfate. The solution was filtered and concentrated in vacuo to give the crude material. The crude material was purified by silica gel column chromatography by eluting with 1:4 EtOAc in hexane to provide 4-chloro-1-(2-iodo-3-methylphenyl)-3-methyl-1H-pyrazole.

1. additionwas added dropwise
2. stirringthe solution was stirred at RT
3. customseparated
4. extractionThe aqueous layer was extracted with EtOAc
5. washThe combined organic extracts were washed with 1N HCl, water, saturated sodium bicarbonate, 1N sodium sulfite
6. dry with materialdried over sodium sulfate
7. filtrationThe solution was filtered
8. concentrationconcentrated in vacuo
9. customto give the crude material
10. customThe crude material was purified by silica gel column chromatography
11. washby eluting with 1:4 EtOAc in hexane