反応 #41104

反応方程式

t-butylhydrazine hydrochloride salt

ethyl (ethoxymethylene)-cyanoacetate

sodium acetate

→

5-amino-1-tert-butyl-1H-pyrazole-4-carboxylic acid ethyl ester

収率 77.0%

溶媒

ethanol

反応条件

後処理

1. 1
   温度refluxed for 16 hours
2. 2
   抽出The separated aqueous phase was extracted three times with dichloromethane
3. 3
   洗浄The combined organic phases were washed successively with water and saturated brine solution
4. 4
   乾燥dried with sodium sulfate
5. 5
   その他The solvent was removed in vacuo

実験手順

A solution containing t-butylhydrazine hydrochloride salt (10 g, 80.3 mmol), ethyl (ethoxymethylene)-cyanoacetate (13.6 g, 80.4 mmol), and anhydrous sodium acetate (8.2 g, 100 mmol) in 100 mL ethanol was stirred and refluxed for 16 hours. The solution was poured into ice-water. The separated aqueous phase was extracted three times with dichloromethane. The combined organic phases were washed successively with water and saturated brine solution and dried with sodium sulfate. The solvent was removed in vacuo to give 5-amino-1-tert-butyl-1H-pyrazole-4-carboxylic acid ethyl ester (13 g, 77%).

出典