반응 #41164

반응 방정식

Cyclopentyl-hydrazine hydrochloride

ethyl (ethoxymethylene)-cyanoacetate

sodium acetate

→

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

수율 79.3%

용매

ethanol

반응 조건

후처리

1. 1
   온도After cooling to room temperature
2. 2
   기타ethanol was removed in vacuo
3. 3
   기타the residue was partitioned between methylene chloride and water
4. 4
   세척The organic phase was washed sequentially with water and brine
5. 5
   추출Each aqueous phase was back extracted with a single portion of methylene chloride
6. 6
   건조dried over sodium sulfate
7. 7
   농축concentrated
8. 8
   기타Purification by flash chromatography
9. 9
   세척eluting with 10-40% EtOAc/hexanes

실험 절차

Cyclopentyl-hydrazine hydrochloride (1.000 g; 7.32 mmol), ethyl (ethoxymethylene)-cyanoacetate (1.026 g, 6.61 mmol) and anhydrous sodium acetate (0.644 g, 7.85 mmol) were combined in ethanol (10 mL) and heated at 70° C. for 20 hours. After cooling to room temperature, ethanol was removed in vacuo and the residue was partitioned between methylene chloride and water. The organic phase was washed sequentially with water and brine. Each aqueous phase was back extracted with a single portion of methylene chloride. The two organic phases were combined, dried over sodium sulfate and concentrated. Purification by flash chromatography, eluting with 10-40% EtOAc/hexanes yielded 5-amino-1-cyclopentyl-1H-pyrazole-4-carboxylic acid ethyl ester (1.170 g, 73%). Mass spectrum: m/z: 224.1 (M+H).

출처