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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

6-(2-hydroxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran (1.1 g) (see Preparation 10) was dissolved in dry dimethylformamide (2 ml) and imidazole (0.55 g) and tert-butyldimethylsilyl chloride (0.61 g) were added. The flask was fitted with a calcium chloride drying tube and the mixture stirred at 40° C. for 90 minutes. 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 was chromatographed on silica using 4:1 hexane: dichloromethane as the eluent to yield 6-(2-tert-butyidimethylsilyloxyphenyl)thio-2,2,3-trimethyl-2H-benzo[b]pyran (1.43 g) as an oil.

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