Triphenylphosphine → (5,7-difluoro-3,4-dihydro-2H-chromen-4-yl)oxy-N,N,2-trimethyl-1-[(4-methylphenyl)-sulfonyl]-1H-benzi midazole-6-carboxamide

Participants

Reaction Steps

To a stirred mixture of 4-hydroxy-N,N,2-trimethyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole-6-carboxamide (110 mg, 0.294 mmol, STEP 7), 5,7-difluoro-3,4-dihydro-2H-chromen-4-ol (164 mg, 0.884 mmol, STEP 8-1) and triphenylphosphine (232 mg, 0.884 mmol) in toluene (5 mL) was added diisopropyl azodicarboxylate (DIAD) (179 mg, 0.884 mmol) at room temperature. The reaction mixture was stirred at room temperature for 6 hours and concentrated in vacuum. The residue was purified by column chromatography on silica gel (ethyl acetate:hexane gradient elution from 1:20 to 10:1) to afford a mixture of the title compound and triphenylphosphine oxide (280 mg, crude) as white solids, which was used in the next step without further purification.

Provenance & Evidence