Reacción #41169

Ecuación de reacción

Cyclopentyl-hydrazine hydrochloride

cyclopentyl-hydrazine hydrochloride

2-dimethylaminomethylene-4,4,4-trifluoro-3-oxo-butyric acid ethyl ester

sodium acetate

→

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

Rendimiento 52.6%

Disolventes

ethanol

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaAfter cooling to room temperature
2. 2
   Otrothe reaction mixture was partitioned between methylene chloride and water
3. 3
   LavadoThe organic phase was washed with water and brine
4. 4
   ExtracciónEach aqueous phase was back extracted with a second portion of methylene chloride
5. 5
   Secadodried over sodium sulfate
6. 6
   Concentraciónconcentrated in vacuo
7. 7
   OtroPurification by flash chromatography
8. 8
   Lavadoeluting with a 10-40% ethyl acetate-hexanes

Procedimiento

Cyclopentyl-hydrazine hydrochloride (0.250 g, 1.83 mmol, Example 64, Step 2), 2-dimethylaminomethylene-4,4,4-trifluoro-3-oxo-butyric acid ethyl ester (0.403 g, 1.68 mmol) and anhydrous sodium acetate (0.163 g, 1.99 mmol) were combined in ethanol (2.5 mL) and heated at 70° C. for 17 hours. After cooling to room temperature, the reaction mixture was partitioned between methylene chloride and water. The organic phase was washed with water and brine. Each aqueous phase was back extracted with a second portion of methylene chloride. The two organic phases were combined, dried over sodium sulfate and concentrated in vacuo. Purification by flash chromatography, eluting with a 10-40% ethyl acetate-hexanes gradient, yielded 1-cyclopentyl-5-trifluoromethyl-1H-pyrazole-4-carboxylic acid ethyl ester (0.244 g, 52%). Mass spectrum: m/z: 277.1 (M+H).

Fuente