Reaktion #2507847

Reaktionsgleichung

1,2-Dihydro-4-((4-ethylphenyl)methyl)-5-(trifluoromethyl)-3H-pyrazol-3-one

t-Butyldimethylsilyl chloride

Water

imidazole

→

desired compound

3-t-butyldimethylsilyloxy-4-((4-ethylphenyl)methyl)-5-(trifluoromethyl)-1H-pyrazole

Lösungsmittel

ethyl acetate

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added in portions
2. 2
   Sonstigewas back to ambient temperature
3. 3
   WaschenThe organic phase was washed with aqueous saturated sodium chloride
4. 4
   Trocknendried over anhydrous sodium sulfate
5. 5
   Einengenconcentrated

Vorschrift

1,2-Dihydro-4-((4-ethylphenyl)methyl)-5-(trifluoromethyl)-3H-pyrazol-3-one (4) (prepared by the method described in J. Med. Chem 1996, 39, 3920-3928) (15.0 g; 55.6 mmol) was dissolved in dimethylformamide (150 ml) and cooled to 0° C. t-Butyldimethylsilyl chloride (9.3 g; 61.1 mmol) was added in portions, and then, imidazole (4.2 g; 61.1 mmol) was added in portions. Then, the resulting mixture was back to ambient temperature, then the mixture was stirred for 3 hours. Water was added to the reaction solution, for extraction twice with ethyl acetate. The organic phase was washed with aqueous saturated sodium chloride, dried over anhydrous sodium sulfate and concentrated, to give the desired compound (21.4 g; 55.6 mmol). (100%)

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