Reaktion #620013

Reaktionsgleichung

4-Dimethylamino-2-oxo-but-3-enoic acid ethyl ester

hydrazine dihydrochloride

→

product

Ausbeute 39.0%

1H-Pyrazole-3-carboxylic Acid Ethyl Ester

Ausbeute 39.0%

Lösungsmittel

EtOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was then heated
2. 2
   Temperaturto reflux for 2 hours
3. 3
   Temperaturto cool to room temperature
4. 4
   Filtrationfiltered
5. 5
   WaschenThe solid was washed with water three times
6. 6
   Sonstigedried
7. 7
   EinengenThe filtrate was concentrated to a thick oil
8. 8
   workup.ADDITIONadded dropwise into a flask with stirred EtOAc (200 mL)
9. 9
   FiltrationThe resulting solid was filtered
10. 10
    Waschenrinsed with a small amount of EtOAc

Vorschrift

4-Dimethylamino-2-oxo-but-3-enoic acid ethyl ester (195 g, 1.14 mol) and hydrazine dihydrochloride (119.7 g, 1 eq) were dissolved in EtOH (1 L) and stirred at room temperature overnight. The mixture was then heated to reflux for 2 hours. The reaction mixture was allowed to cool to room temperature and filtered. The solid was washed with water three times and dried. The filtrate was concentrated to a thick oil and added dropwise into a flask with stirred EtOAc (200 mL). The resulting solid was filtered and rinsed with a small amount of EtOAc. The filtered solids were combined to give the product (62 g, 39% yield). MS (ES) m/z 141.1 (M+H+).

Quelle