تفاعل #41164

معادلة التفاعل

Cyclopentyl-hydrazine hydrochloride

ethyl (ethoxymethylene)-cyanoacetate

sodium acetate

→

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

المردود 79.3%

المذيبات

ethanol

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةAfter cooling to room temperature
2. 2
   أخرىethanol was removed in vacuo
3. 3
   أخرىthe residue was partitioned between methylene chloride and water
4. 4
   غسيلThe organic phase was washed sequentially with water and brine
5. 5
   استخلاصEach aqueous phase was back extracted with a single portion of methylene chloride
6. 6
   تجفيفdried over sodium sulfate
7. 7
   تركيزconcentrated
8. 8
   أخرىPurification by flash chromatography
9. 9
   غسيلeluting with 10-40% EtOAc/hexanes

الإجراء التجريبي

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).

المصدر