Diphosgene → {5-Fluoro-4-[2-methyl-4-(2,3,4,5-tetrahydrobenzo[b]azepine-1-carbonyl)-benzylcarbamoyl]-2-oxo-3,4-dihydro-2H-quinoxalin-1-yl}acetic Acid Tert-Butyl Ester

Participants

Reaction Steps

To a solution of (5-fluoro-2-oxo-3,4-dihydro-2H-quinoxalin-1-yl)acetic acid tert-butyl ester from Example 7A (84 mg, 0.30 mmol) in toluene (4.0 ml) were added trichloromethyl chloroformate (36 μl, 0.30 mmol), diisopropylethylamine (54 μl, 0.30 mmol) and a spatula full of activated carbon. The mixture was heated at reflux for 2 h, cooled, filtered through Celite®, washed with EtOAc and evaporated in vacuo. The residue was taken up in THF (3.0 ml) and added to a solution of (4-aminomethyl-3-methylphenyl)-(2,3,4,5-tetrahydrobenzo[b]azepin-1-yl)methanone from Example F (85 mg, 0.29 mmol) in THF (3.0 ml) while cooling in an ice/water bath. The mixture was allowed to warm to room temperature, stirred for 1 h and evaporated in vacuo. The residue was purified by flash chromatography on silica (eluant EtOAc:pet. ether 75:25) to afford a white solid; yield 120 mg, 66%.

Provenance & Evidence