تفاعل #657253

معادلة التفاعل

ethyl 3-acetyl-4-oxopentanoate

hydrazine hydrate

→

pyrazole

المردود 72.0%

Ethyl 2-(3,5-dimethyl-1H-pyrazol-4-yl)acetate

المردود 72.0%

المذيبات

ethanol

ethanol

ظروف التفاعل

المعالجة

1. 1
   أخرىAfter removing ethanol under vacuum, dichloromethane and water
2. 2
   workup.ADDITIONwere added to the crude product
3. 3
   أخرىthe organic layer was separated
4. 4
   استخلاصThe aqueous layer was extracted further with dichloromethane
5. 5
   غسيلthe combined organic extracts were washed with water
6. 6
   تجفيفAfter drying over MgSO4 and evaporation of the solvent under reduced pressure

الإجراء التجريبي

To a solution of ethyl 3-acetyl-4-oxopentanoate (synthesized as described D. P. Shrout and D. A. Lightner, Synth. Commun. 20 (1990), 2075) (9.676 g, 51.96 mmol) in ethanol, at 0° C., was added slowly a solution of hydrazine hydrate (2.990 g, 59.75 g) in absolute ethanol. The reaction mixture was warmed to room temperature and stirred for 2 hours. After removing ethanol under vacuum, dichloromethane and water were added to the crude product and the organic layer was separated. The aqueous layer was extracted further with dichloromethane and the combined organic extracts were washed with water. After drying over MgSO4 and evaporation of the solvent under reduced pressure, the pyrazole was isolated as a yellow oil. Yield: 72% (6.777 g, 37.2 mmol).

المصدر