反应详情

To a solution of dry pyridine (0.237 g, 300 mmol) in anhydrous methylene chloride (5 mL) was slowly added chromium trioxide (0.15 g, 1.5 mmol) to give a wine colored mixture which was stirred at room temperature for 10 minutes. A solution of ethyl 3-phenyl-4-[(4-chloro-2-nitrophenyl)(hydroxy)methyl]-1H-pyrazole-5-carboxylate (0.10 g, 0.25 mmol) in anhydrous methylene chloride (2 mL) was added to the wine red mixture in three portions over 25 minutes. The reaction mixture was stirred at room temperature for 18 hours. The reaction mixture was filtered and the filtrate extracted with 3×20 mL 3N HCl. The combined organic extracts were dried with sodium sulfate and concentrated via rotary evaporation to give an oil (0.1 g) which was triturated with hexane:ethyl acetate (4:1) to give the title compound as a tan solid (0.075 g, 75%).

1. customto give a wine colored mixture which
2. stirringThe reaction mixture was stirred at room temperature for 18 hours
3. filtrationThe reaction mixture was filtered
4. extractionthe filtrate extracted with 3×20 mL 3N HCl
5. dry with materialThe combined organic extracts were dried with sodium sulfate
6. concentrationconcentrated via rotary evaporation