反应详情

2-(2,4-Dinitrophenyl)-3-methyl-4-nitropyrazole (16.0 g, 0.055 mole) was dissolved in methanol (250 ml). Sodium methoxide (11.0 g, 0.22 mole) was added dropwise as a suspension in methanol. The colour of the reaction mixture changed from yellow to a dark red. The reaction mixture was then stirred at room temperature for 3 h. The methanol was removed in vacuo to give a dark red oil, which was neutralized by pouring onto ice/HCl. The resulting brown precipitate of dinitroanisole was filtered off and discarded. The aqueous filtrate was neutralized with 10% sodium carbonate solution and extracted with ethyl acetate (3×200 ml), dried and evaporated to dryness to give a yellow solid. Crystallisation from ether/methanol gave pale yellow needles of 3-methyl-4-nitropyrazole (6.0 g, 86%).

1. customThe methanol was removed in vacuo
2. customto give a dark red oil, which
3. additionby pouring onto ice/HCl
4. filtrationThe resulting brown precipitate of dinitroanisole was filtered off
5. extractionextracted with ethyl acetate (3×200 ml)
6. customdried
7. customevaporated to dryness
8. customto give a yellow solid
9. customCrystallisation from ether/methanol