Sodium hydride → tert-butyl {[1-{[5-(1,3-dioxolan-2-yl)-2-furyl]sulfonyl}-4-fluoro-5-(2-fluoropyridin-3-yl)-1H-pyrrol-3-yl]methyl}methylcarbamate

Participants

Reaction Steps

To a suspension of sodium hydride (60% in oil, 155 mg) in tetrahydrofuran (10 mL) was added tert-butyl {[5-(2-fluoropyridin-3-yl)-4-fluoro-1H-pyrrol-3-yl]methyl}methylcarbamate (1.04 g) under ice-cooling and the mixture was stirred for 15 min. 15-Crown-5 (354 mg) and a solution of methyl 5-(chlorosulfonyl)-2-furoate in tetrahydrofuran (2 mL) were added dropwise and the mixture was further stirred at room temperature for 1.5 hr. The reaction mixture was concentrated under reduced pressure, and the residue was diluted with water, and extracted with ethyl acetate. The separated aqueous layer was extracted again with ethyl acetate. The combined organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=4:1→1:1) to give the title compound as a brown oil (yield 1.33 g, 78%).

Provenance & Evidence