反应详情

温度

100 °C

12.5 g of p-tolylhydrazine in 150 ml of glacial acetic acid were added to a solution of 16 g of methyl 4-ethoxy-2-oxobut-3-enoat in 100 ml of glacial acetic acid at 50° C. The mixture was stirred at 100° C. for 5 hours, poured into 1 liter of water, and extracted twice with 100 ml of ethyl acetate. The organic phase was washed with saturated NaHCO3 solution and subsequently with water, and dried. After evaporating in a water-pump vaccum, the mixture was separated by distillation in a high vacuum. 4.1 g of methyl 1-(4-methylphenyl)-pyrazole-5-carboxylate of boiling point 116°-120° C./0.01 torr (example 8) and 5.3 g of methyl 1-(4-methylphenyl)-pyrazole-3-carboxylate of boiling point 138°-142° C./0.01 torr were obtained. The compounds were characterized by 1H NMR spectroscopy.

1. extractionextracted twice with 100 ml of ethyl acetate
2. washThe organic phase was washed with saturated NaHCO3 solution and subsequently with water
3. customdried
4. customAfter evaporating in a water-pump vaccum
5. customthe mixture was separated by distillation in a high vacuum