反应详情

1-(3-Chloro-4-fluoro-phenyl)-5-methyl-1H-pyrazole-4-carboxylic acid tert-butyl ester (2.1 g, 6.8 mmol) is treated with cold HCl in dioxane (4.0 N solution, 10 mL, 40 mmol) and stirred for 16 hours at room temperature. The resultant precipitate is collected by filtration, washed with dioxane (2×1 mL) and dried to afford 1-(3-chloro-4-fluoro-phenyl)-5-methyl-1H-pyrazole-4-carboxylic acid as a tan solid (540 mg, 31%).

1. filtrationThe resultant precipitate is collected by filtration
2. washwashed with dioxane (2×1 mL)
3. customdried