Reaktion #440284

Reaktionsgleichung

2-{4-[(3,5-dibromophenyl)sulfanyl]-3,5-diethyl-1H-pyrazol-1-yl}ethanol

2-{4-[(3,5-Dibromophenyl)sulfanyl]-3,5-diethyl-1H-pyrazol-1-yl}ethanol

imidazole

tert-butyl(chloro)dimethylsilane

→

title compound

Ausbeute 72.9%

1-(2-{[tert-Butyl(dimethyl)silyl]oxy}ethyl)-4-[(3,5-dibromophenyl)sulfanyl]-3,5-diethyl-1H-pyrazole

Ausbeute 72.9%

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe mixture was partitioned between diethyl ether (70 ml) and citric acid solution (5% weight:volume in water, 150 ml)
2. 2
   ExtraktionThe aqueous layer was further extracted with diethyl ether (70 ml)
3. 3
   Waschenthe combined organic layers were washed with brine (2×70 ml)
4. 4
   Trocknendried over magnesium sulphate
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated under reduced pressure
7. 7
   SonstigeThe crude product was purified by flash chromatography on silica gel eluting with pentane:dichloromethane (1:1, by volume)

Vorschrift

A solution of 2-{4-[(3,5-dibromophenyl)sulfanyl]-3,5-diethyl-1H-pyrazol-1-yl}ethanol (1.3 g, 3 mmol) (Example 93) in dimethylformamide (3 ml) was treated with imidazole (270 mg, 4 mmol) and tert-butyl(chloro)dimethylsilane (500 mg, 3.3 mmol) and stirred at 20° C. for 15 hours. The mixture was partitioned between diethyl ether (70 ml) and citric acid solution (5% weight:volume in water, 150 ml). The aqueous layer was further extracted with diethyl ether (70 ml) and the combined organic layers were washed with brine (2×70 ml), dried over magnesium sulphate, filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography on silica gel eluting with pentane:dichloromethane (1:1, by volume) to provide the title compound (1.2 g) as a colourless oil.

Quelle