2,2,6,6-Tetramethylpiperidine → methyl 5-[6-({[tert-butyl(dimethyl)silyl]oxy}methyl)-1H-imidazo[4,5-c]pyridin-1-yl]-3-hydroxythiophene-2-carboxylate

Participants

Reaction Steps

To a mixture of 21.2 g of 6-({[tert-butyl(dimethyl)silyl]oxy}methyl)-1H-imidazo[4,5-c]pyridine and 11.36 g of 2,2,6,6-tetramethylpiperidine in 2 l dichloromethane was slowly added a solution of 8.77 g of methyl 2-chloro-3-oxo-2,3-dihydrothiophene-2-carboxylate in 300 ml chloroform at 30-40° C. The reaction mixture was stirred for 12 h, washed with water (2×200 ml) and concentrated under vacuum. The residue was purified by flash chromatography (eluents: ethyl acetate/methanol/triethylamine) two times and after precipitation from ethyl acetate/n-hexane the title compounds were obtained as a mixture of regioisomers.

Provenance & Evidence