Reacción #1532720

Ecuación de reacción

sodium hydroxide

Water

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

product

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

water

→

title compound

1-(3-Chloro-2-pyridinyl)-2,3-dihydro-3-oxo-1H-pyrazole-5-carboxylic acid

Disolventes

methanol

Condiciones de reacción

Tratamiento posterior

1. 1
   Extracciónthe reaction mixture was extracted with ethyl ether, which
2. 2
   Extracciónextracted with ethyl acetate (50 mL)
3. 3
   ExtracciónThe ethyl acetate extract
4. 4
   Lavadowas washed with water (20 mL) and brine (20 mL)
5. 5
   Secadodried over magnesium sulfate
6. 6
   Concentraciónconcentrated

Procedimiento

To a stirred solution of ethyl 1-(3-chloro-2-pyridinyl)-2,3-dihydro-3-oxo-1H-pyrazole-5-carboxylate (i.e. the product of Step B) (1.0 g, 3.7 mmol) in methanol (15 mL) was added water (3 mL). An aqueous solution of sodium hydroxide (50%, 1.0 g, 12.5 mmol) was added dropwise, and the reaction mixture was stirred at room temperature for 3 hours, during which time the reaction mixture turned a clear yellow. Water (20 mL) was added and the reaction mixture was extracted with ethyl ether, which was discarded. The aqueous phase was acidified to pH 2 using concentrated hydrochloric acid and then extracted with ethyl acetate (50 mL). The ethyl acetate extract was washed with water (20 mL) and brine (20 mL), dried over magnesium sulfate and concentrated to give the title compound, isolated as a white solid (0.76 g).

Fuente