반응 #41156

반응 방정식

Cyclohexylhydrazine hydrochloride

ethyl (ethoxymethylene)-cyanoacetate

sodium acetate

→

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

수율 92.9%

용매

ethanol

반응 조건

후처리

1. 1
   온도then cooled to room temperature
2. 2
   농축concentrated
3. 3
   기타The residue was partitioned between methylene chloride and water
4. 4
   추출The separated aqueous phase was extracted with a second portion of methylene chloride
5. 5
   세척The organic phases were successively washed with water and brine
6. 6
   건조dried over sodium sulfate
7. 7
   농축concentrated in vacuo
8. 8
   기타The residue was purified by flash chromatography
9. 9
   세척eluting with a gradient of 25-70% ethyl acetate/hexanes

실험 절차

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).

출처