Diisopropylethylamine → 8-Fluoro-4-(2-methylaminoethyl)-3-oxo-3,4-dihydro-2H-quinoxaline-1-carboxylic acid 2-methyl-4-(2,3,4,5-tetrahydrobenzo[b]azepine-1-carbonyl)benzylamide

Participants

Reaction Steps

Methylamine hydrochloride (68 mg, 1.0 mmol) was added to a solution of 8-fluoro-3-oxo-4-(2-oxoethyl)-3,4-dihydro-2H-quinoxaline-1-carboxylic acid 2-methyl-4-(2,3,4,5-tetrahydrobenzo[b]azepine-1-carbonyl)benzylamide from Example 10 (53 mg, 0.1 mmol) in methanol (4.0 ml) then the mixture was cooled in an ice/water bath. Diisopropylethylamine (185 μl, 1.0 mmol) was added and the mixture was stirred for 20 mins. Acetic acid (0.40 ml) and sodium cyanoborohydride (6.3 mg, 0.1 mmol) were added and the mixture was allowed to warm to room temperature. The mixture was stirred for 3 h, diluted with toluene and evaporated in vacuo. The residue was partitioned between EtOAc and saturated sodium hydrogen carbonate solution and separated. The organic phase was washed with brine, dried and evaporated in vacuo. The residue was purified by flash chromatography on silica (eluant dichloromethane:methanol:triethylamine 95:4:1) to give a white solid; yield 22 mg, 41%.

Provenance & Evidence