Potassium Phosphate, Tribasic → HCID 22495628, compound

Participants

Reaction Conditions

Reaction Steps

A flask purged of oxygen and under a nitrogen atmosphere was charged with 0.104 gm (0.482 mMol) 5-fluoro-7-bromobenzofuran, 0.184 gm (0.723 mMol) bis(pinacolato)di-boron, 0.0043 gm (0.0024 mMol) palladium(II) chloride, 0.016 gm (0.0029 mMol) 1,1′-bis(diphenylphosphino)ferrocene, 0.142 gm (1.45 mMol) potassium acetate, and 3 mL toluene. This mixture was heated at 90° C. for 5 hours and was then poured into 150 mL diethyl ether and filtered through a bed of celite. The filtrate was concentrated under reduced pressure to provide a dark residue. This material was dissolved in 3 mL tetrahydrofuran and the resulting solution purged of oxygen and placed under a nitrogen atmosphere. To this solution were added 0.028 gm (0.0024 mMol) tetrakis(triphenylphosphino)palladium(0), 0.153 gm (0.723 mMol) potassium phosphate, and 0.15 gm (0.434 mMol) 1-(tert-butoxycarbonyl)-2-methyl-4-trifluoromethylsulfonyloxy-1,2,5,6-tetrahydropyridine. The resulting mixture was stirred at reflux for 3.5 hours and was then charged with an additional 0.5 equivalents of 1-(tert-butoxycarbonyl)-2-methyl-4-trifluoromethylsulfonyloxy-1,2,5,6-tetrahydropyridine. The mixture was stirred at reflux for an additional 1.5 hours and was then poured into 150 mL diethyl ether. The mixture was filtered through a bed of celite and the filtrate concentrated under reduced pressure. The residue was dissolved in 2 mL dichloromethane and the solution was subjected to silica gel chromatography, eluting with a gradient of hexane containing 0-5% ethyl acetate. Fractions containing product were combined and concentrated under reduced pressure to provide 0.10 gm (62%) of the desired compound.

Provenance & Evidence