Imidazole → 6-(3-tert-butyldimethylsilyloxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

6-(3-Hydroxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran (2.2 g) (see Preparation 9) was dissolved in dry dimethylformamide (4 ml) and imidazole (1.1 g) and tert-butyidimethylsilyl chloride (1.2 g) were added. The flask was fitted with a calcium chloride drying tube and the mixture was stirred at 40° C. for one hour. Water was added and the mixture was extracted with diethyl ether. The organic extract was washed with aqueous sodium hydrogen carbonate solution (×2), dried (anhydrous sodium sulphate), the solvent removed under reduced pressure and the crude product chromatographed on silica using (4:1 hexane:dichloromethane as the eluent to yield 6-(3-tert-Butyldimethylsilyloxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran (2.84 g) as an oil.

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