Reacción #1532724

Ecuación de reacción

ethyl 1-(3-chloro-2-pyridinyl)-2,3-dihydro-3-oxo-1H-pyrazole-5-carboxyate

product

Ethyl 1-(3-chloro-2-pyridinyl)-2,3-dihydro-3-oxo-1H-pyrazole-5-carboxyate

potassium carbonate

propargyl bromide

water

→

title compound

Rendimiento 95.0%

Ethyl 1-(3-chloro-2-pyridinyl)-3-(2-propynyloxy)-1H-pyrazole-5-carboxylate

Rendimiento 95.0%

Disolventes

acetonitrile

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe reaction mixture was heated
2. 2
   Temperaturaat reflux for 15 minutes
3. 3
   TemperaturaThe mixture was then cooled
4. 4
   Extracciónextracted with a 1:1 mixture of diethyl ether and ethyl acetate
5. 5
   LavadoThe organic extracts were then washed with a saturated solution of sodium chloride
6. 6
   Secadodried over magnesium sulfate
7. 7
   ConcentraciónThe extract was concentrated to dryness on a rotary evaporator
8. 8
   Otrochromatographed on silica gel

Procedimiento

To a solution of ethyl 1-(3-chloro-2-pyridinyl)-2,3-dihydro-3-oxo-1H-pyrazole-5-carboxyate (i.e. the product of Example 1, Step B) (0.5 g, 1.9 mmol) in acetonitrile (20 mL) was added potassium carbonate (0.6 g, 3.8 mmol) and propargyl bromide (1.0 mL, 9.4 mmol). The reaction mixture was heated at reflux for 15 minutes. The mixture was then cooled and treated with water and extracted with a 1:1 mixture of diethyl ether and ethyl acetate. The organic extracts were then washed with a saturated solution of sodium chloride and dried over magnesium sulfate. The extract was concentrated to dryness on a rotary evaporator and chromatographed on silica gel using hexane/ethyl acetate (7:3) as eluent to isolate the title compound (0.45 g, 95% purity) as a red oil.

Fuente