Reacción #41156

Ecuación de reacción

Cyclohexylhydrazine hydrochloride

ethyl (ethoxymethylene)-cyanoacetate

sodium acetate

→

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

Rendimiento 92.9%

Disolventes

ethanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturathen cooled to room temperature
2. 2
   Concentraciónconcentrated
3. 3
   OtroThe residue was partitioned between methylene chloride and water
4. 4
   ExtracciónThe separated aqueous phase was extracted with a second portion of methylene chloride
5. 5
   LavadoThe organic phases were successively washed with water and brine
6. 6
   Secadodried over sodium sulfate
7. 7
   Concentraciónconcentrated in vacuo
8. 8
   OtroThe residue was purified by flash chromatography
9. 9
   Lavadoeluting with a gradient of 25-70% ethyl acetate/hexanes

Procedimiento

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).

Fuente