Triphenylphosphine → Methyl 5-[6-({[tert-butyl(dimethyl)silyl]oxy}methyl)-1H-imidazo[4,5-c]pyridin-1-yl]-3-{1-[4-fluoro-2-(trifluoromethyl)phenyl]ethoxy}thiophene-2-carboxylate

Participants

Reaction Steps

Under a nitrogen atmosphere, 2.1 g of methyl 5-[6-({[tert-butyl(dimethyl)silyl]oxy}methyl)-1H-imidazo[4,5-c]pyridin-1-yl]-3-hydroxythiophene-2-carboxylate are dissolved in 60 ml anhydrous dichloromethane. Consecutively, 1.56 g of 1-[4-fluoro-2-(trifluoromethyl)phenyl]ethanol, 3.3 g triphenylphosphine (polymer bound, ˜3 mmol/g) and 2.3 g of di-tert-butyl azodicarboxylate are added to the solution. The reaction mixture is stirred at room temperature for 15 h and then filtered. The filter cake is washed with 50 ml of a dichloromethane/methanol mixture (95:5). The filtrate is concentrated to dryness under reduced pressure. The crude is purified by flash chromatography [Silica gel, eluent: ethyl acetate/cyclohexane, elution gradient of 5/95 (v/v) to 70/30 (v/v) to yield the title product.

Provenance & Evidence