反应 #41156

反应方程式

Cyclohexylhydrazine hydrochloride

ethyl (ethoxymethylene)-cyanoacetate

sodium acetate

→

5-amino-1-cyclohexyl-1H-pyrazole-4-carboxylic acid ethyl ester

收率 92.9%

溶剂

ethanol

反应条件

后处理

1. 1
   温度then cooled to room temperature
2. 2
   浓缩concentrated
3. 3
   其他The residue was partitioned between methylene chloride and water
4. 4
   萃取The separated aqueous phase was extracted with a second portion of methylene chloride
5. 5
   洗涤The organic phases were successively washed with water and brine
6. 6
   干燥dried over sodium sulfate
7. 7
   浓缩concentrated in vacuo
8. 8
   其他The residue was purified by flash chromatography
9. 9
   洗涤eluting with a gradient of 25-70% ethyl acetate/hexanes

实验过程

Cyclohexylhydrazine hydrochloride (3.057 g, 20.29 mmol, CAS #24214-73-1, purchased from Aldrich) was combined with ethyl (ethoxymethylene)-cyanoacetate (3.390 g, 20.04 mmol) and anhydrous sodium acetate (2.080 g, 25.36 mmol) in 30 mL ethanol. The mixture was heated at 70° C. for 16 hours then cooled to room temperature and concentrated. The residue was partitioned between methylene chloride and water. The separated aqueous phase was extracted with a second portion of methylene chloride. The organic phases were successively washed with water and brine and then combined, dried over sodium sulfate and concentrated in vacuo. The residue was purified by flash chromatography eluting with a gradient of 25-70% ethyl acetate/hexanes to give 5-amino-1-cyclohexyl-1H-pyrazole-4-carboxylic acid ethyl ester (4.42 g, 92%). Mass spectrum: m/z: 238.1 (M+H).

来源