反应详情

温度

30 °C

To a solution of 90% t-butyl nitrite (50 mL, 0.37 mol) in 200 mL DMF was added in portions ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate (39 g, 0.23 mol), maintaining the temperature at around 30° C. After the addition, the resulting mixture was warmed to 50° C. and stirred at that temperature for 0.5 h. The mixture was poured into 100 mL conc HCl and 40 mL water and extracted with CH2Cl2. The organic solution was washed with water, brine, dried and concentrated. Vacuum distillation of the residue gave 32.4 g of ethyl 1-methyl-1H-pyrazole-4-carboxylate as a clear liquid. b.p. 65-80° C. at 0.1 torr.

1. additionAfter the addition
2. temperaturethe resulting mixture was warmed to 50° C.
3. extractionextracted with CH2Cl2
4. washThe organic solution was washed with water, brine
5. customdried
6. concentrationconcentrated
7. distillationVacuum distillation of the residue