Reacción #41161

Ecuación de reacción

(Tetrahydro-pyran-4-yl)-hydrazine hydrochloride

ethyl (ethoxymethylene)-cyanoacetate

sodium acetate

→

5-amino-1-(tetrahydro-pyran-4-yl)-1H-pyrazole-4-carboxylic acid ethyl ester

Rendimiento 92.3%

Disolventes

ethanol

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaAfter cooling to room temperature
2. 2
   Concentraciónthe reaction was concentrated
3. 3
   Otrothe residue was partitioned between methylene chloride and water
4. 4
   OtroThe organic phase was separated
5. 5
   Lavadowashed with water
6. 6
   ExtracciónEach aqueous phase was back extracted with methylene chloride
7. 7
   Secadodried over sodium sulfate
8. 8
   Concentraciónconcentrated in vacuo
9. 9
   OtroThe crude material was purified by flash chromatography
10. 10
    Lavadoeluting with 60-100% ethyl acetate/hexanes

Procedimiento

(Tetrahydro-pyran-4-yl)-hydrazine hydrochloride (1.975 g, 12.94 mmol), ethyl (ethoxymethylene)-cyanoacetate (1.958 g, 11.57 mmol) and sodium acetate (1.370 g; 16.70 mmol) were combined in ethanol (16 mL). The mixture was heated at 80-85° C. for 17 hours. After cooling to room temperature, the reaction was concentrated and the residue was partitioned between methylene chloride and water. The organic phase was separated and washed with water and then brine. Each aqueous phase was back extracted with methylene chloride. The two organic phases were combined, dried over sodium sulfate and concentrated in vacuo. The crude material was purified by flash chromatography eluting with 60-100% ethyl acetate/hexanes to give 5-amino-1-(tetrahydro-pyran-4-yl)-1H-pyrazole-4-carboxylic acid ethyl ester (2.554 g, 92%).

Fuente