Reaktion #594916

Reaktionsgleichung

triethylamine

(1-chloro-2-methylpropylidene)methane-1,1-dicarbonitrile

2,6-dichlorophenylhydrazine hydrochloride

→

pyrazole

Ausbeute 62.2%

5-amino-1-(2,6-dichlorophenyl)-3-isopropyl-1H-pyrazole-4-carbonitrile

Ausbeute 62.2%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction was then heated
2. 2
   Temperaturto reflux for 18 h
3. 3
   Sonstigepartitioned between EtOAc (150 mL) and 1N NaOH (100 mL)
4. 4
   ExtraktionThe aqueous layer was extracted with EtOAc (2×150 mL)
5. 5
   Waschenthe combined organic layers were washed with 10% aq. citric acid (150 mL), sat. aq. NaHCO3 (150 mL), and brine (150 mL)
6. 6
   TrocknenThe organic layer was dried (MgSO4)
7. 7
   Filtrationfiltered
8. 8
   Sonstigeevaporated
9. 9
   SonstigeThe crude product was recrystallized from EtOAc/hexane

Vorschrift

A solution of (1-chloro-2-methylpropylidene)methane-1,1-dicarbonitrile (9.4 g, 61 mmol) in THF (250 mL) was treated with 2,6-dichlorophenylhydrazine hydrochloride (13.0 g, 61 mmol) followed by triethylamine (12.3 g, 122 mmol). The reaction was then heated to reflux for 18 h. The reaction was then cooled to room temp and partitioned between EtOAc (150 mL) and 1N NaOH (100 mL). The aqueous layer was extracted with EtOAc (2×150 mL) and the combined organic layers were washed with 10% aq. citric acid (150 mL), sat. aq. NaHCO3 (150 mL), and brine (150 mL). The organic layer was dried (MgSO4), filtered, and evaporated. The crude product was recrystallized from EtOAc/hexane to yield the desired pyrazole (11.2 g, 62%).

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