反応 #41156

反応方程式

Cyclohexylhydrazine hydrochloride

ethyl (ethoxymethylene)-cyanoacetate

sodium acetate

→

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

収率 92.9%

溶媒

ethanol

反応条件

後処理

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

実験手順

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).

出典